Taking Xingtai, a typical industrial city, as the study object, the pollution characteristics of O₃ were analyzed based on air quality monitoring and meteorological data from 2018 to 2022. The geographical detector method was employed to investigate the individual and combined impacts of meteorological factors and precursors on O₃ pollution. An air quality model was used to assess the sensitivity of O₃ generation, and EKMA curves were adopted to determine optimal emission reduction ratios in different control areas. The research revealed that the monthly average O₃ concentrations in Xingtai exhibited an inverted V-shaped pattern, with peak values observed in June (199.28μg/m³) and trough values recorded in January and December (37.16μg/m³). The hourly O₃ concentrations and their variation ranges across seasons followed the order: summer > spring > autumn > winter. Significant seasonal differences were identified in the driving factors affecting surface O₃ concentrations. On an annual scale, meteorological factors were found to exert greater influence on O₃ pollution than precursor pollutants. Temperature and solar radiation were identified as the main positive driving factors for O₃ concentration increases, while humidity and precipitation served as primary negative drivers. CO and NO₂ were positive drivers in spring and summer but showed opposite effects in autumn and winter. The central urban area with surrounding counties, along with Qinghe and Linxi counties, were classified as VOCs control areas. The northwestern and central-eastern counties were designated as synergistic control areas for both VOCs and NO_x. The optimal emission reduction ratios for between VOCs and NO_x were determined to be 1.5:1 and 1:1, respectively, in the different control areas.

This study investigated the spatiotemporal variations of ozone (O₃) pollution and O₃ formation sensitivity in the Yangtze River Delta (YRD) with the air quality model CAMx and an optimized photochemical indicator (PH₂O₂/PHNO₃). The critical years of emission reduction strategies (2013, 2017, 2020, and 2030) were selected to simulate and predict changes in ozone concentration and formation sensitivity under different emission scenarios. The results revealed a north-south gradient in O₃ concentrations, with higher levels in northern areas and lower levels in southern areas. The ozone formation sensitivity regimes were divided by an Anqing-Nanjing-Suzhou-Jiaxing line. The northern aeras of the line were governed by a VOCs-limited regime (occupying 43.3% of the total area) and the southern areas were predominantly NO_x-limited (45.3%), with transitional zones covering the remaining area. Under fixed meteorological conditions, continuous reduction in anthropogenic emissions during 2013~2020led to a sustained decline in the daily maximum 8-hour average (MDA8) O₃ concentration, and a shift of the ozone formation regime from VOCs-limited to NO_x-limited. In 2030, O₃ levels in urban hotspots such as Shanghai are likely to increase, despite an overall reduction in regional O₃ levels. The shift towards the NO_x-limited region will continue, increasing by 30.2% from 2013 levels. Only specific cities along the Yangtze River and areas with heavy traffic emissions will remain VOCs-limited. In summary, excluding the impact of climate change, the emission mitigation strategies can effectively decrease the ozone levels in the YRD. Meanwhile it is still necessary to coordinate the reduction rates of NO_x and VOCs in VOCs-limited cities to prevent increases in O₃ levels.

In this study, ozone (O₃) formation sensitivity in Henan Province was assessed using the FNR indicator derived from the Community Multiscale Air Quality (CMAQ) model outputs, which was used to classify the province into distinct sensitivity zones. Observation data from national monitoring sites in Henan Province (2015~2022) were integrated with the Temperature method (Temp), Nighttime method (Night), 5_th percentile method, and CMAQ-Night method to evaluate regional background O₃ concentrations during both warm and cold seasons and their evolution trends across different zones. The results indicate that northern and eastern Henan are primarily VOC-limited, while the western and southern parts are predominantly NO_x-limited. In northern and eastern Henan, the planetary boundary layer exhibits stronger VOC-limitation than the troposphere. The results demonstrate a regime transition, where VOC-limited zones gradually shift to transition zones, and these transition zones evolve into NO_x-limited regimes. Background O₃ concentrations estimated by the Temp, Night, and 5_th percentile methods were 96.0, 103.2 and 88.4μg/m³, respectively, accounting for 64.9 69.7 and 59.9% of O₃-8h during the warm season. In the cold season, the corresponding estimates were 56.0, 73.6, and 40.0μg/m³, with the Temp and 5th percentile methods contributing 88.4 and 63.2% of O₃-8h, respectively. The result from the Night method exceeded O₃-8h, likely due to the significant influence of NO titration effects during the cold season. The annual increase in cold-season O₃ concentrations was attributed to the weakening of NO titration effects, driven by substantial reductions in NO_x emissions. The CMAQ-Night method revealed that, in June, background O₃ concentrations ranged from 73.1 to 151.4μg/m³ across Henan Province, accounting for 60% (in northern Henan) to 98% (in western Henan) of O₃-8h, with an average value of 103.3μg/m³ (71.6%). In VOC-limited zones of northern Henan, O₃ pollution was jointly driven by background contributions and local generation, while in the mountainous and hilly regions of western Henan, background contributions dominated. From 2015 to 2017, the increase in O₃ concentrations across the province was primarily driven by local generation (57%), whereas the decline from 2017 to 2020 was mainly attributed to reductions in background O₃ concentrations (58%). These findings highlight significant potential for further reducing locally generated O₃ through targeted emission control measures.

The typical compound pollution of PM_2.5 and O₃ in Baoding City was investigated in this study. Objective weather classification of sea-level pressure and 10m wind fields in the Beijing-Tianjin-Hebei region during the autumn-winter and spring-summer seasons was conducted using the Principal Component T-mode (PCT) method. Backward trajectory analysis (PSCF, CWT) and meteorological-air quality modeling system (WRF-CAMx) were applied to identify the source contributions and transport pathways of PM_2.5 and O₃ under pollution-related weather types. From 2019 to 2022, the annual average PM_2.5 concentration in Baoding showed a significant decline of 26.9%, whereas O₃ exhibited a fluctuating trend with a slight reduction of only 2.2%, indicating limited improvement. Monthly average concentrations of both pollutants demonstrated pronounced seasonal patterns. In autumn and winter, high-pressure systems dominated, and weather types T5 (eastern high-pressure rear, 11.6%), T6 (saddle-type, 11.6%), and T9 (isobaric field, 5.2%) were most frequently associated with PM_2.5 pollution events. In contrast, low-pressure systems prevailed in spring and summer, with weather types S3 (isobaric field, 12.9%) and S7 (northwest low-pressure rear, 16.8%) contributing notably to O₃ pollution. Local emissions were identified as the dominant source of PM_2.5 during pollution weather types. Under T5, additional contributions originated mainly from Handan and Shijiazhuang; under T6, from Shanxi Province and Shijiazhuang; and under T9, from Shanxi and Inner Mongolia. For O₃ pollution, local sources accounted for the largest share. Under S3, transport from surrounding cities played a secondary role, whereas under S7, contributions from southwestern regions, including Henan, Handan, Shanxi, and Shijiazhuang, were more prominent.

To enhance the independence and controllability of regional atmospheric environment numerical prediction and its capability to support air quality forecast and air pollution warning, a CMA-GFS driving numerical prediction system (RAEMS-CMA) was established and operationally implemented. This system was based on the NCEP-GFS driving Regional Atmospheric Environmental Modeling System for eastern China (RAEMS-NCEP). The forecast effects evaluation on the major air pollutants over the YRD region from July 4^th, 2023, to July 3^rd, 2024, was executed. Evaluation results showed that RAEMS-CMA had good performance in forecasting the major air pollutants, e.g. correlation coefficients were generally over 0.7 and root mean square errors were 30%~70% of corresponding observation means. The performance was consistent in different forecast lengths of 24h ~ 96h. Further analysis indicated that the performance differs from air pollutants, with better skills in forecasting PM_2.5 and O₃. The prediction of PM₁₀ was underestimated, while the others were overestimated. It also showed better forecast capability over the north region than over the south. The intercomparison indicated that RAEMS-CMA had slightly superior performance to that of RAEMS-EC (which was driven by ECMWF) and accordant to RAEMS-NCEP, while their differences were usually less than 5%. These results proved the applicability of CMA-GFS in numerical air quality prediction over the YRD region. At the same time, the divergent performance in pollutants and regions suggests further efforts on technological improvements and application approaches to numerical air quality prediction.

To investigate concentration variations, source characteristics, and relationships with environmental factors of biogenic volatile organic compounds (BVOCs) in urban areas, we conducted measurements of BVOCs at 100meters using a proton transfer reaction mass spectrometer (PTR-ToF-MS) at the Shenzhen Meteorological Gradient Tower in the spring and summer of 2024. During the observation period, the concentrations of isoprene, Methacrolein+methyl vinyl ketone (MVK+MACR), and monoterpenes were measured at (0.24±0.29)×10^-9, (0.20±0.22)×10^-9, and (0.11±0.14)×10^-9, respectively. These results indicate the isoprene concentrations were lower than those reported in Beijing during the same seasons, likely due to differences in environmental conditions and oxidation during vertical transport. Temporally, BVOC concentrations peaked at midday under high temperatures and strong sunlight. Spatially, higher concentrations were observed in the upwind direction towards the south, where vegetation is lush. The initial isoprene concentrations, calculated from the product concentrations, were significantly higher than the observed concentrations, suggesting a high degree of air mass aging. Source apportionment based on tracers revealed that the average contribution of anthropogenic sources to monoterpene concentrations was only 9.9%, but this contribution could reach 21.7% at night. Temperature was identified as a significant environmental factor influencing BVOC concentrations. The study found that the empirical coefficients of initial isoprene concentrations with temperature were more consistent with those of MVK+MACR than with observed isoprene concentrations, indicating that initial isoprene better represents the temperature dependence of plant emissions.

To investigate the vertical distribution and source characteristics of formic acid in the atmospheric boundary layer, online measurements of formic acid and related air pollutants were conducted at six heights from the ground level to 335m in autumn 2021 using iodide chemical ionization mass spectrometry (I-CIMS) coupled with a multi-inlet tubing system at the Shiyan Meteorological Gradient Tower in Shenzhen. Results revealed that the average ground-level formic acid concentration during the campaign was 0.7 ppb, lower than previously reported values from other regions globally. Vertically, formic acid concentrations exhibited a consistent height-dependent pattern with an initial increase followed by a decrease, peaking at 120m during both daytime and nighttime. This vertical maximum was particularly pronounced in daylight hours. Correlation analyses with co-measured pollutants (ozone, NO_x, PM_2.5) demonstrated that the sources of formic acid were influenced by both primary emissions and secondary formation. A vertical stratification of sources was identified: contributions below 120m predominantly originated from direct emissions of vehicle exhausts, while photochemical secondary formation became the dominant source above 120m.

Accurate estimation of CO₂ emissions at the regional scale, particularly in large urban agglomerations, is essential for effective greenhouse gas mitigation. In this study, the WRF-STILT model, combined with three prior anthropogenic CO₂ emission inventories (EDGAR v6.0, an improved version of EDGAR v6.0 integrated with GCG v1.0, and the ODIAC inventory) was used to simulate atmospheric CO₂ concentrations in the Yangtze River Delta during winter 2018. Observational data from a 70-meter tower in Quanjiao, Anhui province, served as the reference. A scale factor Bayesian inversion method was applied to optimize the simulation results, allowing estimation of anthropogenic CO₂ emission fluxes in the region. The results indicate that the CO₂ concentrations simulated by the WRF-STILT model effectively reflect the emission characteristics of the Yangtze River Delta. In winter, simulations based on the improved inventory aligned more closely with observations than those using EDGAR v6.0alone. The posterior CO₂ emission fluxes estimated using the EDGAR and improved inventories were (0.199 ± 0.005) and (0.200 ± 0.007) mg/(m²·s), respectively—representing decreases of 0.02 and 0.01mg/(m²·s) compared to the prior flux estimates. The Bayesian inversion method significantly optimized the prior emissions from the EDGAR inventory. When calculating total CO₂ emissions for the region using the improved inventory, power generation and industrial sectors were identified as the primary sources of uncertainty. Additionally, due to the low nocturnal boundary layer height, the model tended to overestimate the contribution of elevated emission sources near the observation site. Future simulations should ensure the WRF model accurately captures hourly boundary layer heights, and that vertical emission profiles of point sources are incorporated into emission inventories.

To clarify the variation characteristics and causes of urban atmospheric CO₂ concentrations during heatwave periods, this study investigates Hangzhou—a typical city in the Yangtze River Delta—using the WRF-STILT atmospheric transport model, the EDGAR anthropogenic emission inventory, high-precision laser spectrometer observations, and a Bayesian optimization inversion algorithm. Results show that heatwaves significantly affect atmospheric CO₂ concentrations: daytime concentrations are lower, while nighttime concentrations are higher compared to non-heatwave periods. The spatial representativeness of measurement sites and changes in CO₂ emissions are the main factors influencing atmospheric CO₂ levels in Hangzhou. Heatwaves also lead to notable changes in spatial representativeness: during heatwaves, local emissions account for 80.5% of the observed CO₂ compared to only 51.6% during non-heatwave periods, and representative spatial range is smaller. In addition, CO₂ emissions from various anthropogenic sectors respond differently to heatwaves: emission from the manufacturing, energy, and refining and conversion sectors increase, while emissions from transportation decreases.

This study systematically analyzes and compares the spatiotemporal coverage and distribution patterns of the Level-2 atmospheric column CO₂ concentration (XCO₂) products from OCO-3, OCO-2, and GOSAT satellites over China. The results showed that the annual average spatial coverage of the Level-2 XCO₂ products in China were 43.38%, 21.19% and 0.40% for OCO-3, OCO-2, and GOSAT, respectively, with corresponding monthly average coverages were 4.77%, 2.43% and 0.16%. Notably, OCO-3 exhibited a significant lower monthly average coverage in odd-numbered months (2.23%) compared to even-numbered months (7.31%). There were significant spatial distribution differences in the coverage of the three satellite products. The coverage of OCO-2 and OCO-3 in southern and central China was significantly lower than that in northeastern, northwestern and northern China. In contrast, GOSAT's observations were extremely sparse, mainly concentrated in eastern China. In addition, OCO-3 identified over 20 hotspot observation areas over provincial capitals and industrial cities, which showed markedly higher coverage and observation frequency. From 2019 to 2022, all three satellite XCO₂ products reveal consistent increasing trends in annual average XCO₂, albeit with declining annual increment. Seasonal pattern showed consistently higher XCO₂ in spring and winter than in summer and autumn. Spatially, annual average XCO₂ showed higher concentrations in the eastern than western China, and in southern than northern China. However, the location of XCO₂ extreme value varied across satellites, and significant differences in XCO₂ concentrations were observed among different products within the same sub-region.

This study investigated the effect of ozone and photolysis rate on formic acid formation mechanisms from oxidation of benzene across five major Chinese cities (Beijing, Shanghai, Guangzhou, Xi'an, and Chengdu) between 2014~2023. Combining the spatiotemporal patterns of ozone (maximum 8-hr average from China's National Environmental Monitoring Center), J_(NO2) (derived from solar zenith angle calculations) and the oxidation mechanism of benzene, the effect of ozone and J_(NO2) on formic acid production from the atmospheric oxidation of benzene were modelled. Key findings revealed that formic acid yields from benzene exhibited: (1) strong seasonal correlation with ozone levels across all cities (R² = 0.96); (2) consistent trends with that of J_(NO2) in Beijing, Shanghai, Xi'an, and Chengdu (R² = 0.80~0.94), contrasting with Guangzhou's weak correlation (R² = 0.27); (3) distinct seasonal variations with significant lower production in winter than other seasons in all cities, consistent peak production of formic acid in summer in Beijing, Xi'an, and Chengdu, alternating maxima between spring and summer in Shanghai, and peak formation in autumn in Guangzhou.

This study evaluated the small-scale atmospheric dispersion performance of the Micro-SWIFT SPRAY (MSS) model and the GPU-accelerated QES model (GPU-QES) in the complex environment of a nuclear power plant site. Based on wind tunnel experimental data from the Sanmen Nuclear Power Plant, two typical wind direction dispersion scenarios were simulated by both models, and the results were compared in terms of wind field and concentration field predictions, including horizontal ground-level wind and concentration fields, as well as vertical wind speed and concentration profiles. The results indicated that GPU-QES outperformed MSS in wind speed prediction, especially in the areas between buildings, where the underestimation of wind speed is reduced by about 53%. Furthermore, GPU-QES simulated the three-dimensional wind field 450times faster than MSS, generating wind data over a 9km² area with 35million grid points in just 4s. In plume dispersion prediction, high-concentration areas were effectively reproduced by both models, but GPU-QES showed higher consistency with actual values in low-concentration regions. Statistical analysis revealed that both models meet internationally accepted model criteria. However, higher simulation accuracy was demonstrated by GPU-QES in most metrics, especially in the building ground area, where the fraction of predictions within a factor of two of the observations (FAC2) was 4.5% higher than that of MSS. Additionally, due to differences in the dispersion behavior behind buildings between MSS and GPU-QES, simulation accuracy was improved by averaging the results of both models (FAC2reached 71.8%). On the other hand, due to differences in concentration calculation methods, GPU-QES generated the plume approximately 48times faster than MSS. Therefore, a clear advantage was shown by GPU-QES over MSS in nuclear emergency response scenarios that required rapid and accurate predictions.

This study investigates the chemical composition and brown carbon (BrC) light-absorption characteristics of smoke particles from six industrial biomass boilers. The mass fractions of organic carbon (OC) and elemental carbon (EC) in the smoke particles were 1.96% and 0.78%, respectively, while water-soluble inorganic ions accounted for 46.3% of the mass. Significant differences in the chemical composition of smoke particles were observed across different boilers, influenced by factors such as fuel types, boiler loads, and dust removal techniques. Soot-EC from bag-filtered boilers exhibited a higher OC/EC ratio (10.8) compared to cyclone-filtered boilers (2.27). The carbon components were predominantly OC₂, OC₃, OC₄ and EC1, with a highly variable Char-EC/Soot-EC ratio (average: 18.7, range: 0.25~86.0). Water-soluble inorganic ions were primarily K⁺, Cl^-, Na⁺, SO₄^2- and Ca²⁺, constituting 81.0%~93.6% of the total ions. The spectral properties of BrC, including water-soluble organic carbon (WSOC) and methanol-soluble organic carbon (MSOC), showed limited correlation with boiler fuel, load, or dust removal method. The mass absorption efficiency at 365 nm (MAE₃₆₅) was closely related to the OC/EC ratio, suggesting a strong link between BrC photo-absorption capacity and combustion conditions. The mass absorption efficiency of WSOC (MAE_WSOC) from industrial biomass boiler was 4~5 times higher than that from biomass cookstoves and 5~9 times higher than open biomass combustion emissions, as reported in literature. The study elucidates the light absorption characteristics of brown carbon in smoke particles emitted from industrial biomass boiler and their correlation with combustion conditions.

This review summarizes the extracellular electron transfer mechanisms in anaerobic ammonium oxidation (anammox) systems and strategies for their enhancement, categorizing the influence mechanisms of carbon-based materials on anammox bacteria into three aspects: conductivity of carbon-based materials, functional groups on their surfaces, and interactions between microbial communities and extracellular polymeric substances. Studies have demonstrated that biochar, activated carbon, carbon nanomaterials, and iron-carbon composites can regulate the anammox process by mediating extracellular electron transfer. Carbon-based materials primarily enhance anammox performance through shortening reactor start-up periods, improving nitrogen removal efficiency, and alleviating pollutant inhibition effects. These materials not only effectively enrich microorganisms but also promote the stability enhancement of granular sludge, demonstrating significant application potential in anammox systems. Future research should focus on material modification to further improve the sustainability of carbon-based materials in practical applications.

To precisely control the denitrification process such that NO₃^--N is reduced solely to NO₂^--N without further reduction to N₂, short-term aeration was implemented to enhance the nitrate-to-nitrite transformation ratio (NTR) of denitrifying phosphorus-accumulating organisms (DPAOs). The results demonstrated that after aeration intensification, phosphorus removal efficiency in the reactor improved (from 84.62% to 88.34%). When aeration durations were set at 5, 10, and 15minutes, the NTR values reached 36.09%, 89.14%, and 91.86%, respectively. However, extending aeration to 20minutes resulted in elevated effluent nitrate concentrations (10.11mg/L). As aeration duration increased, the content of pre-anoxic electron donors (PHBs) gradually diminished, which was identified as the primary reason for nitrite accumulation. Furthermore, aeration induced an increase in the relative abundance of DPAOs while decreasing that of endogenous denitrifying glycogen-accumulating organisms (DGAOs). Based on the outcomes of the partial denitrification coupled with phosphorus removal (PDPR) process, the feasibility of implementing the N-PDPR-Anammox process in practical engineering applications was discussed.

In order to strengthen the rapid and stable formation of hydrostatically oxygenic photogranules (HSP), a strategy of inoculating Oscillatoria sp., a typical kind of filamentous cyanobacteria, into activated sludge at the early stage of cultivation was proposed. The photogranulation process, morphology, extracellular polymeric substances contents, surface thermodynamics properties and microbial community were analyzed to elucidate the mechanism for efficient photogranulation in R1 (cultivated with Oscillatoria sp.). Results showed that the mixed liquid suspended solid of mature HSP in R1 (2.17g/L) was larger than that in R2 (cultivated without Oscillatoria sp.) (2.03g/L), and the surface of HSP in R1 was smoother. Values of PN/PS in R1 (2.01) was slightly larger than R2 (1.45) on 30d, implying that inoculating Oscillatoria sp. enhanced the hydrophobicity of granular sludge. Furthermore, results showed that the interfacial free energy was strengthened in R1 with the potential energy barrier of 2616.75kT, which was lower than the potential energy barrier in R2 (5037.85kT). The EPS producing bacteria were enriched and the relative abundance of enzymes related to EPS production was increased by 8%~156% in HSP after being strengthened by Oscillatoria sp. Overall, inoculating filamentous cyanobacteria Oscillatoria sp. into activated sludge facilitated the attachment and aggregation between bacteria and microalgae in HSP, contributing to the rapid development of HSP.

This review summarized the research progress on mixotrophic metabolic mechanisms of anaerobic ammonium-oxidizing bacteria (AnAOB), and provided perspectives on future research directions and highlighted the engineering implications. Current studies indicated that the mixotrophic metabolism of AnAOB could be influenced by factors such as the C/N ratio, organic matter concentration and types. However, the metabolic rates and micro-mechanisms of different AnAOB strains in metabolizing small organic molecules (e.g., acetate, propionate) remain unclear. In recent years, advanced ¹³C isotope labelling technology (DNA-SIP) and single-cell techniques have provided novel approaches to elucidate the pathways of small organic molecules uptake and metabolism in AnAOB. Multi-omics analysis showed that AnAOB fix inorganic carbon through the reductive acetyl-CoA pathway and harboured multiple pathways for small organic molecules metabolism, including denitrifying nitrate to ammonium (DNRA), formate metabolism, acetate metabolism, propionate metabolism, and the tricarboxylic acid cycle, yet the specific mechanisms remain controversial. Future research could focus on the electron transfer mechanisms, endogenous organic matter utilization strategies, and small organic molecules assimilation capabilities in the mixotrophic metabolism of AnAOB, aiming to optimize the enrichment and nitrogen removal performance of AnAOB, and expand their application potential in complex wastewater treatment.

Feammox functional microorganisms were enriched from anaerobic digestion sludge with NH₄⁺-N and Fe(Ⅲ) supplementation and their long-term nitrogen removal performance was evaluated. Feammox activity was detected on day 66and remained stable in subsequent batches. The relative abundances of the potential Feammox functional bacteria Geobacter and Anaeromyxobacter increased by 457-fold and 11.6-fold, respectively. Metagenomic analysis revealed a significant increase in the total relative abundance of functional genes associated with three nitrite transformation pathways: ammonia oxidation to nitrite (amo, hao), nitrite denitrification to nitrogen gas (nirSK, norB, nosCZ), and nitrite reduction to ammonium (nirABD, nrfAH). The addition of the electron shuttle AQDS promoted extracellular electron transfer and enhanced the ammonia removal efficiency by 17.8%.

A novel efficient phosphate adsorbent (CF-La) was synthesized by treating activated carbon fibers using lanthanum with impregnation method. The adsorption isotherms, adsorption kinetics, one-way experiments, and actual water sample tests were carried out. The adsorption isotherm studies demonstrated that the adsorption process conforms to the Langmuir model, indicating monolayer adsorption, with the maximum adsorption capacity of 5.78mg/g at 333K. Kinetic analyses revealed that the adsorption process follows the pseudo-second-order kinetic model, involving both physical and chemical adsorption mechanisms. The pH and competitive ions experiments indicated that the best adsorption effect was achieved under neutral environment, and the best adsorption result was achieved under neutral condition. The effects of five anions on CF-La were in the following order: S^2- > SO₄^2->CO₃^2-> Cl^-≈NO₃^-. The recyclability assessment through five adsorption-desorption cycles showed that CF-La retained >80% adsorption and desorption efficiency. By conducting characterization with SEM and BET on the modified material before and after, it is confirmed that lanthanum has been successfully loaded onto the surface. Analysis of the materials before and after adsorption using XPS and FTIR indicates that the synthesized material features a mesoporous structure, and the presence of lanthanum in two different oxidation states on the surface is beneficial for enhancing the adsorption efficiency. The experiment on sample water verified that CF-La showed excellent adsorption performance on inorganic phosphorus and organic phosphorus in Chaohu Lake, Anhui Province, and the water samples from Chaohu Lake in summer and winter could be reduced to within the threshold of cyanobacterial bloom after adsorption for 10h.

A composite material (CBC-nZVI) was synthesized by green reduction of Artemisia arenaria extract to produce nanoscale zero-valent iron (nZVI), which was subsequently loaded onto biochar derived from waste corn straw. This composite was employed for the removal of hexavalent chromium (Cr(Ⅵ)) from aqueous solutions. The study investigated the adsorption kinetics and thermodynamics, as well as the effects of pH, dosage, and coexisting ions on Cr(Ⅵ) removal by CBC-nZVI. The material was characterized using SEM, FTIR, XRD, and XPS to elucidate the Cr(Ⅵ) removal mechanisms. The adsorption kinetics of Cr(Ⅵ) onto CBC-nZVI fit best with the Elovich model, indicating that intraparticle diffusion was the rate-controlling step. The adsorption isotherm fitted the Freundlich model, indicating that the adsorption was a spontaneous endothermic and entropy-increasing process. The Cr(Ⅵ) removal efficiency improved with increasing reaction temperature, material dosage, and solution acidity. Under optimal conditions (298K, pH 2, and dosage of 1.0g/L), 100% removal efficiency was achieved for a Cr(Ⅵ) concentration of 30mg/L. The presence of coexisting cations or anions in the solution inhibited the removal of Cr(Ⅵ) by the CBC-nZVI to varying degrees, with the order of inhibition being Cd²⁺>Mg²⁺>Ca²⁺>Cu^2-, and CO₃^2->Cl^->NO₃^->SO₄^2-. The results of characterization of CBC-nZVI and batch adsorption experiments showed that the Cr(Ⅵ) removal mechanism by CBC-nZVI involves electrostatic adsorption, chemical reduction, functional group complexation, and precipitation. nZVI reduces adsorbed Cr(Ⅵ) to Cr(Ⅲ), which is then removed through surface complexation with functional groups and co-precipitation with Fe(Ⅲ) as Cr(Ⅲ)-Fe(Ⅲ) complexes. The loaded nZVI and CBC exhibited a synergistic effect in the removal of Cr(Ⅵ) by the composite material.

To solve the problems of high synthesis cost and lack of specific adsorption sites on traditional zeolites surface, polydopamine-modified coal gangue based zeolite was successfully synthesized by combining alkali melting hydrothermal method and impregnation coating method using coal gangue as raw material and dopamine as the polymerization monomer and applied for efficient adsorption of Cd(Ⅱ) from aqueous solution. The adsorption performance was investigated by batch adsorption experiments, and adsorption mechanism was revealed by SEM-EDS and XPS method. The results showed that polydopamine coating significantly improved the adsorption capacity of coal gangue-derived zeolite. The adsorption process conformed to the Langmuir adsorption isotherm model and pseudo-second-order model, suggesting that Cd(Ⅱ) adsorption by Zeolite@PDA was monolayer and chemical adsorption, and the theoretical maximum adsorption capacity could reach 130.89mg/g, which was two times as high as that of Zeolite (q_max=66.49mg/g). Thermodynamic studies indicated that Cd(Ⅱ) adsorption by Zeolite@PDA was a spontaneous, endothermic process with increased disorder at the solid-liquid interface. SEM-EDS and XPS analysis showed that cation exchange between Na⁺and Cd(Ⅱ) as well as surface complexation between surface functional groups and Cd(Ⅱ) played a primary role for Cd(Ⅱ) removal.

An original strategy for immobilization of photocatalyst on the gelatinous membrane surface to fabricate the composite photocatalytic membrane through submerged precipitated phase inversion method based on the gel property of organic casting solution was proposed to solve the problem of membrane fouling and photocatalyst recovery. The effect of photocatalyst on the structure and performance of the composite photocatalytic membrane was studied systematically. With the increase of photocatalyst load, the micropore of the composite photocatalytic membrane was occupied by the photocatalyst to form a uniform and complete photocatalytic layer, which contributed to improve the optical property, hydrophilicity and water flux of the composite photocatalytic membrane. The water flux was 628L/(m²·h), 92.76% and 41.53% of fluvastatin and TOC were removed by the composite photocatalytic membrane with ZnIn₂S₄ loading of 1.2mg/cm². Compared with PVDF membrane, the permeability and photocatalytic performance were enhanced and the stability of performance was demonstrated during the long-term operation. The outstanding antifouling performance of the composite photocatalytic membrane was confirmed due to the photocatalytic degradation of pollutant adsorbed on the membrane surface or pore. The stable immobilization of photocatalyst and efficient utilization of incident light were simultaneously achieved for the composite photocatalytic membrane. The structure and performance of the composite photocatalytic membrane were also regulated. A feasible way for beneficial combination of photocatalysis and membrane separation was provided.

Supported bimetallic Pd-Rh catalysts were prepared using the impregnation method. The effects of the active components content and the carrier on the catalytic activity of the bimetallic Pd-Rh catalysts were investigated with 4-fluorophenol (4-FP) as the representative fluorinated organic compounds (FOCs). The results showed that the presence of Rh significantly enhanced their catalytic activity for the hydrodefluorination (HDF) of 4-FP, and 2% Pd-1% Rh/AC exhibited good catalytic activity for the HDF of 4-FP, and the conversion of 4-FP over 2% Pd-1% Rh/AC reached 95.62% within 90min. Furthermore, the type of the carrier played a significant role on the catalytic activity of bimetallic Pd-Rh catalysts. 2%Pd-1%Rh/CB exhibited the highest catalytic activity for the HDF of 4-FP when carbon black (CB) was used as a carrier, and thus the complete HDF of 4-FP was achieved within 80min. Catalyst characterization (BET, ICP-MS, RS, TEM, and XPS) indicated that the carriers with more surface defects favored the catalysts exhibited higher catalytic activity, which in turn enabled 2%Pd-1%Rh/CB and 2%Pd-1%Rh/CNTs to exhibit higher catalytic activity for the HDF of 4-FP. Moreover, 2%Pd-1%Rh/CB possessed more Pd⁰, which is more conducive to the activation of the H₂, and in turn promoted catalytic HDF of 4-FP. Thus, 2%Pd-1%Rh/CB possessed the highest catalytic activity for the HDF of 4-FP.

A spherical Co-based catalyst (Co-BC) was successfully synthesized via ion-exchange and molding (drying, binding, rolling, calcination) using ZSM-5 as support and Co(NO₃)₂ as active component, with ultralow Co content (0.94wt.%). Multiple characterizations (EDS/XRD/ICP/XPS) demonstrated Co-BC's efficient PMS activation for aqueous acetone (CVOC model) degradation. Under the conditions of 5×10^-6acetone (initial pH=7), 7.5mmol/L PMS dosage, 10g/L Co-BC dosage, the removal efficiency of acetone can reach 100% in 2hours, with a pseudo first order kinetic constant of 0.077min^-1. Radical quenching experiment and electron spin-resonance spectrometer (ESR) characterization results indicated that the excellent performance was attributed to synergy of radicals (SO₄^·-, ^·OH, O₂^·-) and nonradical (¹O₂). Co-BC performed good removal efficiency (70%~100%) for acetone within a wide pH range (3~11). After being reused for 5times, Co-BC still exhibited a removal rate of 90% for acetone. The Co leaching amount from the Co-BC/PMS system was merely 0.61mg/L, well within the national wastewater discharge limit of 1mg/L and significantly lower than that (9.86mg/L) of the powder catalyst under identical conditions, demonstrating the superior catalytic performance and stability of Co-BC.

A fully symmetric "dual-anion membrane" flow-electrode capacitive deionization (SFCDI) device was developed for treating wastewater containing hexavalent chromium (Cr(Ⅵ)). By employing dual anion-exchange membranes and operating in a short-circuit discharge mode, efficient Cr(Ⅵ) removal can be achieved without the need for high concentration background ions. Results showed that, a key feature of this configuration is its ability to prevent Cr³⁺ back-diffusion and total chromium concentration rebound, which are common issues in traditional FCDI systems using cation-exchange membranes. Under conditions of 1.2V applied voltage and an initial pH of 5.0, the SFCDI reduced the Cr(Ⅵ) concentration from 50mg/L to 0.41mg/L within 150minutes, achieving a total chromium removal efficiency of 97.55% with an energy consumption of only 0.12kWh/m³. Compared to traditional FCDI, SFCDI significantly improved the total chromium removal efficiency while effectively preventing Cr³⁺ backflow. Further research systematically analyzed the effects of voltage, activated carbon content, pH, and coexisting anions on performance and demonstrated the applicability and stability of SFCDI in continuous operation and actual electroplating wastewater treatment. Within 180minutes, the removal rate of Cr(Ⅵ) in actual electroplating wastewater reached 97.68%, showcasing its potential as a green, efficient, and low-energy solution.

Developing a new method based on flow cytometry for rapid determination of the number of microplastics in drinking water, in response to the lack of rapid monitoring techniques that do not require visual sorting or pre-processing. The results showed that the use of Nile red dye (NR), methanol as the solvent, a dye concentration of 10μg/mL, a dyeing time of 10minutes, and flow cytometry for the quantitative analysis of microplastics in water, could reduce the testing time of a single sample to less than 14minutes. This method was used to analyse microplastics in influent and effluent water from a commercial bottled water plant and an ultrafiltration membrane. The results showed that the microplastic concentration in commercial bottled water was in the range (0.46~1.52)×10⁵ particles/L. The newly used polyvinylidene fluoride (PVDF) ultrafiltration membrane posed a higher risk of releasing microplastics only during the initial filtration stage (1d), and the release of microplastics during long-term operation could be disregarded. This new membrane's microplastic release could be analysed with 99.99% efficiency and effectiveness. Additionally, it can efficiently and effectively remove 99.99% of microplastics from feed water.

In response to the combined inhibition effects of sodium salt, heavy metals and antibiotics in the practical application of high-load anaerobic co-digestion (AcoD) of food waste (FW) and waste activates sludge (WAS), a series of batch experiments were conducted to investigate the individual and combined inhibitory effects of sodium salt (1~16g Na⁺/L), zinc ion (180~900mg Zn²⁺/L) and ciprofloxacin (5~60mg CIP/L) on the freshly discharged sludge and room temperature stored sludge from the high-load AcoD system. The results of single inhibition batch experiments indicated that the inhibition strengths of the three inhibitors on methanogenic efficiency were in the following order: CIP > Zn²⁺ > Na⁺. Furthermore, the results of the combined inhibition tests showed that the combined inhibition rate of high concentrations of Na⁺, Zn²⁺ and CIP was as high as 97.8% for the freshly discharged sludge. However, the combined inhibition rates were reduced to 74.4%~92.2% for the stored sludge under the room temperature. The reasons for the differences between the fresh sludge and storage sludge suffering three inhibitors may be due to the formation of more extracellular polymers for the stored sludge under room temperature. Meanwhile, the room temperature storage condition also changed the interaction patterns of the three inhibitors. The results of high-throughput microbial sequencing showed that Methanosarcina spp. with a small change in relative abundance (96.0%) and Firmicutes with an increase in relative abundance (31%~54.1%) in the sludge after room-temperature storage significantly enhanced the combined inhibitory thresholds of the three inhibitors, providing a better way to enhance the stability regulation of high-load AcoD in the coexistence of multiple inhibitors.

To comparatively investigate the influences of direct current (DC) and alternating current (AC) on the composting maturity of pig manure, fresh pig manure and corn stalks were utilized as raw materials. Based on aerobic composting, 3V DC and 3V AC were respectively applied, with no electric field application serving as the control (CK). A 42-day composting experiment was carried out. The results demonstrated that the high-temperature periods (>50℃) of the CK, DC, and AC treatments lasted for 9, 9, and 8days respectively, and the maximum temperatures were 68.3, 69.3, and 76.5℃ respectively. At the conclusion of composting, the pH values of the CK, DC, and AC treatments were 7.71, 7.92, and 7.61 respectively, the EC values were 3.75, 3.11, and 3.82mS/cm respectively, and the C/N ratios were 11.40, 10.51, and 11.96 respectively. The physicochemical properties of the compost in each treatment conformed to the basic requirements for harmlessness. At the end of composting, the moisture contents of the CK, DC, and AC treatments were 55.35%, 54.70%, and 45.45% respectively, the seed germination indices (GI) were 76%, 99%, and 87% respectively, and the ratios of humic acid to fulvic acid (HA/FA) were 1.53, 2.03, and 1.62 respectively. In summary, DC reduced the composting maturity time by 18%, and the effect of DC in promoting the composting maturity of pig manure was superior to that of AC. AC increased the maximum temperature of the compost by approximately 8℃, but it significantly decreased the moisture content of the compost.

This study analyzed the soils from riparian zones with different water level elevations in the Chongqing metropolitan area. The effects of soil Fe/Mn minerals and aggregate composition/stability on nitrogen and phosphorus under different urbanization levels and water level elevations were investigated by methods including wet sieving of aggregates, selective extraction, regression analysis and structural equation modeling. The results showed that no significant differences in iron and manganese speciation across urbanization or water level elevation gradients, with the riparian soils mainly composed of free iron oxide and amorphous manganese oxide. The composition and stability of soil aggregates exhibited significant differences across different urbanization and water level elevation gradients. The >2mm aggregates and aggregate stability increased with increasing water level elevation, while the<0.053mm aggregates exhibited an inverse relationship. At 165m water level elevation, county areas exhibited higher proportions of the >2mm aggregates and greater aggregate stability compared to the metropolitan core. TN and TP were significantly varied in different urbanized areas, with higher levels observed in the metropolitan core compared to county areas. TN, AN and AP increased with the increase of aggregate stability in the metropolitan core, whereas TP decreased with the increase of aggregate stability in the county areas. The content of TN, TP, AN and AP were (756.33±198.27)mg/kg, (399.97±108.25)mg/kg, (27.84±15.58)mg/kg and (15.03±11.15)mg/kg, respectively. The structural equation modeling results showed that soil pH regulated nitrogen and phosphorus dynamics in the riparian zone mainly by influencing the speciation of Fe, Mn minerals and the stability of the aggregates. In conclusion, the risks of nitrogen and phosphorus pollution in the metropolitan core are higher than that in the county areas, whereas water level elevation exhibited no significant impact on the pollution across the study area. Stabilized soil aggregates and Fe, Mn oxides can effectively immobilize nitrogen and phosphorus, thereby mitigating water pollution risks.

A 14-d indoor simulated short-duration rainfall (10min for a single rainfall) experiment was conducted with different rainfall intensities (60, 90, 120 and 180mm/h) and slope gradients (0°, 5°, 10° and 20°) to observe the runoff and sediment yield and MPs loss from the soil of sloping croplands. We investigated the migration characteristics of MPs in the horizontal and vertical directions of soil after rainfall, and explored the effects of rainfall intensity and slope gradient on soil MPs migration in sloping croplands. The results showed that: Under short-duration rainfall of 60and 90mm/h treatment, no runoff and sediment yield and MPs loss were observed. The runoff (213.11~261.70mm) and sediment yield (1191.68~1391.40g/m²) and MPs loss (23113~39953n/m²) increased with the increase of rainfall intensity in the rest of the treatments. The runoff and sediment yield and MPs loss were all zero at 0° slope gradient, and MPs loss was significantly higher at 20° (34570.92n/m²) than at 10° (23113.37n/m²). The MPs loss showed a firstly increasing and then decreasing trend along with the simulated rainfall experiment, and the MPs loss showed a significant positive correlation with both runoff and sediment yield (P<0.05). The total amount of MPs migration in the horizontal direction in surface soil ranged from 4.73 to 31.00n/g, which decreased with the increase of distance. There was a positive correlation between the amount of horizontal MPs migration and rainfall intensities (P>0.05). The total amount of vertical migration of MPs in soil column ranged from 1.41to 11.59n/g, which decreased with the increase of soil depth. The amount of vertical MPs migration showed a positive correlation with rainfall intensities and slopes (P>0.05). The results indicate that extreme rainfalls of short-duration lead to soil MPs loss from sloping croplands, and rainfall intensity and slope gradient are important factors affecting the MPs loss and changing the MPs distribution in soil.

The effects of two polarity fractions of pig manure DOM on the transport of doxycycline, enrofloxacin, florfenicol, and sulfamethazine in the surface and subsurface soils of a Lei bamboo forest were examined in this study. The results of batch experiment showed that the addition of the hydrophilic fraction of pig manure DOM significantly reduced the adsorption of doxycycline, enrofloxacin, and florfenicol in the soils, while the addition of the hydrophobic fraction of pig manure DOM significantly enhanced the adsorption of doxycycline and sulfamethazine. It was found that enrofloxacin and doxycycline could not break through any of the tested soil columns. The additions of either polarity fraction of pig manure DOM decreased the breakthrough recovery of florfenicol in surface soil columns by 2.25% and 20.43%, respectively, while the addition of either DOM fraction greatly increased the breakthrough recovery of florfenicol in subsurface soil columns (to nearly 100%). In surface soil columns, the addition of the hydrophilic fraction of pig manure DOM increased the breakthrough recovery of sulfamethazine, while the addition of the hydrophilic fraction of pig manure DOM decreased the breakthrough recovery of sulfamethazine. In subsurface soil columns, the addition of either DOM fractions markedly decreased the breakthrough recovery of sulfamethazine. Irrespective of the addition of hydrophilic/hydrophobic fraction of pig DOM, florfenicol exhibited a higher breakthrough recovery than sulfamethazine, implying that florfenicol has the highest leaching risk.

Based on the relevant studies conducted over the past few decades, in this article, the research status of atmospheric precipitation chemistry in China's offshore and coastal zones was systematically summarized in terms of precipitation pH and conductivity, the abundance and sources of major chemical constituents, the fluxes of nutrient wet deposition, and their ecological and environmental effects. The future research trends were also projected. The results showed that the pH and conductivity of precipitation in China's offshore and coastal zones were generally high in the north and low in the south due to the neutralization effect of alkaline ions from sand/construction dust in the northern region and the smaller precipitation amount there. The main chemical components in precipitation in China's offshore and coastal areas were dominated by 、、Ca²⁺、Cl^-、. The type of acid rain was primarily a mixture of sulfuric and nitric acids. The wet deposition characteristic of common ions in precipitation varied slightly across China's four major offshore sea areas. Except for the Bohai Sea, wet deposition was the main form in other sea areas, and it generally showed a pattern of wet season being greater than dry season. The Yellow Sea area had the highest ion deposition flux. Short-term heavy rainfall could affect the marine environment. The different components and proportions of input nutrients from wet deposition could influence the structure of marine plankton communities to some extent. Under the combined influences of sea, land, and human activities, the atmospheric precipitation in China's offshore and coastal waters exhibited chemical characteristics distinct from those in inland areas, which could have complex and far-reaching impacts on the offshore ecological environment. Future research should focus on land-sea coordination. It should delve deeper into the intrinsic influences and feedback mechanisms between terrestrial atmospheric pollutant emissions, precipitation chemical components, atmospheric deposition, and offshore ecosystem evolution. This approach may better explore the relationship between human activities and marine ecosystem evolution from the perspective of atmospheric deposition.

A total of 24 sediment samples were collected from the Yellow River Zhengzhou Section to explore the influence of confluence on the distribution and pollution of microplastics in the sediments of the middle and lower reaches of the Yellow River. To investigate the pollution distribution characteristics of microplastics, quantitative and qualitative analysis were conducted by using stereomicroscopy and fourier transform infrared spectroscopy method. Subsequently, cluster analysis was performed to examine the relationship of the microplastics pollution distribution between the main and tributary streams. The results showed that the mean values of microplastic abundance in the sediments were (1340.97 ± 314.84) n/kg and (2372.22 ± 604.17) n/kg during the wet season and dry season, respectively. Overall, the abundance of microplastics showed a trend of higher tributary than main stream, and higher downstream than upstream. Among them, fibrous microplastics accounted for the highest proportion, and dominated by blue, black, and transparent, with the majority of the particle size less than 2mm. The main polymer type was polyethylene terephthalate (PET), and the waste water discharges from washing and household waste disposal were identified as the major sources. Moreover, increased diversity in shapes and types of microplastic were observed after confluence, with a reduction in the fraction of the dominant colours (blue, black, clear) and an expansion in the proportion of small particle sizes (<2mm). This indicates that the tributaries, as the source, contributed to the composition and distribution of microplastics in the main stream sediments after confluence, even affecting their migration.

The study focused on the influence of calcium and magnesium ions (Ca²⁺ and Mg²⁺) in karst areas on adsorption behavior between algal organic matter (AOM) of Chlorella sp. and Pseudanabaena sp. and extracellular polymeric substances (EPS) extracted from bacterial cultures were conducted. The adsorption experiments, the fitting of kinetic and isotherm adsorption models, and the analysis of spectroscopic techniques revealed the influence of divalent cations on the biosorption between EPS and AOM. The results showed that in the presence of divalent ions (Ca²⁺=89.38mg/L, Mg²⁺=17.59mg/L), the biosorption efficiencies of the EPS were improved by bridging the negatively charged functional groups (which was consistent with adsorption under quasi-secondary kinetics). Among them, the adsorption efficiency of Chlorella AOM increased from 31.57% to 59.99% due to its richer functional group structure, which was significantly higher than that of Pseudanabaena AOM (from 59.59% to 62.77%). 3D-EEM analysis showed that aromatic protein (AP) and soluble microbial product (SMP) fractions dominated the adsorption system, and Ca²⁺ and Mg²⁺ altered the stability of fluorescent components during biosorption process. In combination with a specific UV wavelength SUVA₂₅₄, the adsorption induced an increase in the content of aromatic compounds. The characteristic peak shifts detected by FTIR in the bands of 3300~3600cm^-1 (O-H/N-H groups) and 1600~1650cm^-1 (C=O groups) revealed that divalent ions combined with related functional groups to form coordinate bonds and caused bridging effects. This study demonstrated that the divalent cations enhanced the adsorption strength of AOM and EPS through charge neutralization and bridging effects.

This study investigated the accumulation and translocation characteristics of emerging short-chain per- and polyfluoroalkyl substances (PFAS) in a typical submerged macrophyte Aquarius uruguayensis through controlled exposure experiments. The target pollutants included six short-chain PFAS (three perfluoroalkyl carboxylic acids (PFCAs) and three perfluoroether acids (PFEAs)). A. uruguayensis demonstrated bioaccumulation capability of all six short-chain PFAS from water, with whole-plant bioconcentration factors (BCF_total) ranging from 3.0 to 46.0L/kg, primarily detected in leaves with average shoot bioconcentration factors (BCF_shoot) of 2.5~62.2L/kg; In addition to roots and stems, A. uruguayensis leaves were also proven capable of accumulating PFASs independently, with stronger absorption capacity than roots and stems; A. uruguayensis showed selective accumulation of the six short-chain PFAS, preferentially concentrating hydrophilic small-molecule PFASs, with plant BCF showing significant negative correlations with logK_ow and molecular mass(ρ₁= -0.62, ρ₂= -0.81, P<0.05), and its BCF decreases with the increase of logK_ow and molecular mass; Short-chain PFAS underwent translocation within the plant, with a high contribution from roots to leaves, and a low contribution from leaves to roots.

Surface sediments of Dongting Lake were selected as the research object and the concentrations of non-extractable polycyclic aromatic hydrocarbons (PAHs) in the samples were analyzed using a combination of silanization and acidification methods. The study aims to investigate the impact of non-extractable residues on the pollution levels and source analysis of PAHs. The inclusion of non-extractable residues significantly altered the concentration and compositional characteristics of PAHs in the samples, raising the proportions of 3-ring PAHs from (19.78% ± 8.80%) in extractable fractions to (32.97% ± 11.16%) in total concentrations. The proportions of non-extractable PAHs did not exhibit a significant strong correlation with organic carbon or particle size, but were more affected by the total concentration of targets and pollution sources. Source apportionment results revealed that, after considering non-extractable residues, the main pollution sources shifted from traffic emissions (46.91%) to biomass and coal combustion sources (40.70%). The non-extractable residues play an important role in the source analysis of PAHs.

Dissolved organic matter (DOM) in surface water, which serves as a significant component within the carbon cycle, plays a vital role in the biogeochemical cycle of aquatic ecosystems. The triplet excited state of DOM (³DOM^*), singlet oxygen (¹O₂), along with hydroxyl radicals (·OH), which are the photochemical products generated from DOM, were taken as the research targets. Three regression algorithms were employed to constructed the machine learning (ML) models predictive models for evaluating importance of features including environmental factors, ultraviolet-visible light parameters and fluorescence parameters. The ML model based on the categorical boosting algorithm exhibited better performance for the prediction targets in the test set, with R² values of 0.9344, 0.8091, and 0.7775, respectively. Temperature, DOC, and pH were identified as the most important features for predicting ³DOM^*, ¹O₂ and ·OH, respectively. When applying the chained ML model incorporating with the categorical boosting algorithm, the prediction performance for ¹O₂ and ·OH was further optimized. For ¹O₂ the R² value in the test set increased from 0.8091 to 0.8233, and the RMSE decreased from 1.322 to 0.418. For ·OH the R² value in the test set rose from 0.7775 to 0.8094, and the RMSE dropped from 2.982 to 0.312. Additionally, the ML models perform better than the partial least squares regression model in predicting ³DOM^*, ¹O₂ and ·OH, indicating that the ML models possessed strong capability to handle non-linear relationships. The feature importance analysis based on ML successfully distinguished the key features in the DOM photochemical reaction. This finding can provide direct evidence for the intensive management of numerous influencing factors.

From October 2023 to September 2024, regular monitoring of water quality parameters and CO₂ concentrations in river water and groundwater was conducted in the upstream watershed of the Nantiao River in Lin'an, to quantitatively investigate their spatiotemporal variability. Results showed that both riverine and groundwater CO₂ concentrations exhibited pronounced temporal fluctuations. On a monthly scale, peak CO₂ concentrations in both river water and groundwater occurred in July, whereas the minima were temporally asynchronous, observed in December for rivers and January for groundwater, respectively. And seasonally, CO₂ concentrations in both river water and groundwater followed the order:summer > spring > autumn > winter. Overall, groundwater CO₂ concentrations averaged (152.04 ± 35.15) μmol/L, approximately 4.57 times higher than those in river water (33.24 ± 6.19μmol/L), indicating that groundwater may represent a significant potential source of aquatic CO₂ emissions in this region. CO₂ levels were markedly elevated in agricultural zones (river:68.47μmol/L; groundwater: 306.09μmol/L) compared to forested areas (river: 20.64μmol/L; groundwater: 73.93μmol/L). Significant positive correlations (P < 0.01) were observed between CO₂ concentrations and agricultural-related water quality indicators (e.g., TN, TP, DOC), whereas negative correlations were found with DO, pH, and water temperature. Multiple linear regression revealed that the optimal spatial scales of land-use type combination influence on CO₂ concentrations were 750m for river water (R² = 0.88) and 1250m for groundwater (R² = 0.58). Within these spatial buffers, riverine CO₂ concentrations were most strongly associated with residential land cover (r = 0.90, P < 0.01), while groundwater CO₂ was more influenced by cropland proportion (r = 0.83, P < 0.05). These findings suggest that intensive agricultural activities may significantly contribute to CO₂ enrichment in groundwater, which in turn serves as an important source of aquatic CO₂ emissions in the upstream watershed of the Nantiao River in Lin'an.

Based on the indoor two-dimensional sandbox DNAPL remediation experiment, the changes of DNAPL were monitored by the imaging method and the resistivity imaging method to evaluate the effectiveness and feasibility of the resistivity imaging method for monitoring. The results showed that: In the DNAPL infiltration experiment, both the resistivity imaging method and the imaging method could reflect that the DNAPL infiltration was mainly vertical and was mainly affected by gravity. Through the spatial moment analysis of the saturations obtained by the two methods, it was found that the trends of the horizontal centroids of the two methods were quite different, while the trends of the changes in the vertical centroid positions were basically the same. In the DNAPL remediation experiment, with the injection of the SDS solution, the relative resistivity value at the center of the DNAPL pollutant decreased from 25 Ω·m to - 10 Ω·m, and the saturation decreased from 0.42 to 0.15. When the correlation analysis was carried out at specific positions in the sandbox, the correlations between resistivity and saturation were 0.72, 0.84, and 0.92 respectively, and the correlation coefficients were all greater than 0.6, indicating that the two monitoring methods had consistency in interpreting the remediation process. By comparing the monitoring effects of the two methods on the DNAPL infiltration and remediation processes, it was found that during the infiltration process, the imaging method had a better monitoring effect. The imaging method could provide high - precision infiltration images and had a meticulous ability to capture the dynamic changes of DNAPL. During the remediation process, the resistivity imaging method had a better effect. The resistivity imaging could penetrate the medium to monitor the diffusion of the surfactant in different layers and spaces and obtain the macroscopic distribution trend.

In recent years, frequent coastal water environmental issues have been caused by economic and population development. In this study, water quality sampling was conducted in the Guan River, Huai River, and their adjacent coastal areas from October 30 to November 1, 2022, and from June 12 to June 14, 2023. The eutrophication status of the water bodies in the region was evaluated using the organic pollution index, nitrogen-to-phosphorus ratio, and eutrophication index method. Based on the Delft3D model, a three-dimensional hydrodynamic water quality model was established for the coastal areas of the Guan River and Huai River in northern Jiangsu Province. The transport and transformation processes of chemical oxygen demand (COD), ammonia nitrogen (NH₃-N), chlorophyll-a (Chl-a), total nitrogen (TN), and total phosphorus (TP) were simulated. Six different discharge scenarios were designed, including varying the pollutant discharge volume from the rivers (reduced by 20%, reduced by 50%, and increased by 30%) and different discharge timings (normal discharge and discharge during ebb tide when estuary gates were opened). The results showed that the water quality concentration distribution in the coastal areas of the Guan River and Huai River exhibited significant temporal and spatial characteristics. The average concentrations of COD, NH₃-N, Chl-a, and TN were higher in summer than in winter. Spatially, the average COD concentration in the Guan River channel was lower than that in the estuarine coastal area, while the average concentrations of NH₃-N, Chl-a, TN, and TP gradually decreased along the Huai River channel toward the estuary. The overall water quality concentration in the study area displayed a fan-shaped diffusion trend from the river channels to the estuarine coastal zone. Future scenario simulations indicated that reducing the discharge volume by 50% and discharging pollutants during ebb tide when the gates were opened could most effectively reduce pollutant concentrations in the study area.

This study constructed a data-driven RF-LSTM model to predict Total Nitrogen (TN) concentrations in the Haihe River, based on monitoring data from 69 water quality stations collected between 2021 and 2024. By coupling the Random Forest (RF) algorithm with a Long Short-Term Memory (LSTM) neural network, the model also explored the spatiotemporal variation and key influencing factors of TN. Results showed that TN concentrations were relatively high in 2021 and lower in 2022, with annual averages ranging from 4.97 to 5.22mg/L. Across the five watersheds, TN levels displayed a U-shaped seasonal pattern, peaking in January and February and reaching the lowest levels in August. Temperature and dissolved oxygen were identified as the main influencing factors. TN concentration showed a highly significant negative correlation with temperature and a highly significant positive correlation with dissolved oxygen. The RF-LSTM model outperformed the traditional standalone LSTM model in prediction accuracy (R²:0.830~0.939, R²:0.818~0.931) and demonstrated stronger generalization performance.

The plastisphere is a mobile reservoir of harmful microorganisms and genes such as pathogenic bacteria and antibiotic resistance genes, but the current understanding of the occurrence and dissemination risks of pathogenic bacteria in the plastisphere is still insufficient. The distribution and transmission characteristics of plastisphere pathogens in different environmental media are not yet clear. This article systematically introduces the definition and composition of the plastisphere, summarizes the occurrence status of microplastics and pathogenic bacteria in the plastisphere in water environment, soil environment, anthropogenic environment, and atmospheric environment. Results showed that Vibrio, Pseudomonas, and Acinetobacter are common pathogenic bacteria in the plastisphere. The transmission routes and potential health risks of pathogenic bacteria in plastics were summarized. It was found that microplastics carrying pathogenic bacteria could spread among water body, soil, and atmospheric environments, promoting the spread and proliferation of pathogenic bacteria and antibiotic resistance. Finally, prospects for future research are proposed. This article could provide a basis for a comprehensive assessment of the risk of microplastics pollution.

This study investigated the aquatic toxicity effects and underlying mechanisms of thin-layer molybdenum disulfide (MoS₂) using the Microcystis aeruginosa as a model organism. The results demonstrated that various concentration of MoS₂ (0.01~50mg/L) significantly inhibited algal growth during short-term exposure (0~7 days), with the highest inhibition rate of 75% observed in the 50mg/L group after 6days of cultivation. Throughout the 7-day exposure phase, MoS₂ exhibited strong dose-dependent inhibitory effects on pigment biosynthesis and biomass accumulation, as evidenced by concentration-responsive reduction in pigment content (<0.5mg/L), polysaccharides and proteins (<0.05mg/mL), and lipids synthesis (<2×10⁵ fluorescence units). When exposure duration extended to 14~21 days, the observed inhibitory effects gradually alleviated, though high-concentration treatments (50 and 10mg/L) still maintained substantial growth inhibition. Mechanistic analysis revealed that photoactivated MoS₂ nanoparticles generated reactive oxygen species (ROS), triggering acute/chronic oxidative stress in algal cells. During the initial 0~7 day exposure, intracellular ROS levels, superoxide dismutase (SOD) activity, and extracellular polymeric substances (EPS) secretion all significantly increased. These oxidative stress indicators progressively normalized during prolonged exposure (14~21 days). However, under high-concentration exposure conditions (50 and 10mg/L), the oxidative stress response exceeded cellular defense capacity, ultimately causing irreversible membrane damage. These findings provide fundamental data and theoretical support for ecological risk assessment of MoS₂ nanomaterials in aquatic environments.

To clarify the ecological risks of antibiotics in aquatic environments regarding bacterial toxicity and resistance, norfloxacin (NOR) and ceftazidime sodium (CTX) were selected as test compounds. Characteristic parameters including EC50and lower concentrations inducing 10% mutation/conjugation transfer promotion rates were employed. Binary antibiotic mixtures were designed using the direct equipartition ray method to investigate their toxicity and resistance-inducing effects on Escherichia coli (E. coli). Results demonstrated hormetic effects in both individual and combined exposures, with maximum growth promotion, mutation promotion, and conjugation transfer promotion rates reaching 38.40%, 101.26%, and 28.73%, respectively. Compared with individual exposure, the maximum promotion rate of mixed antibiotics on E.coli growth and mutation was reduced, along with decreased relative safety concentrations for mutation and conjugation transfer. Higher NOR proportion in mixtures resulted in lower EC₅₀ values, elevated maximum mutation/conjugation promotion rates, and reduced safety concentrations. The combined action patterns transitioned from additive/synergistic/synergistic to synergistic/antagonistic/antagonistic for toxicity/mutation/conjugation transfer effects respectively as concentrations increased. Higher NOR proportions diminished the maximum synergistic intensities for growth/mutation promotion and antagonistic intensity for conjugation transfer. The concentration ratio in antibiotic mixtures was identified as a critical factor for assessing bacterial toxicity and resistance risks in aquatic environments.

To address the limitations of conventional spectroscopic techniques in microplastic detection and comprehensively assess microplastic occurrence in wild marine fish, this study developed a pyrolysis-thermal desorption-gas chromatography/mass spectrometry (Py-TD-GC/MS) method. This approach demonstrated excellent recovery rates (>90%) for microplastic extraction and quantification. On this basis, this method was used to quantify the mass concentrations of PP, PE, PS and PVC (0.22~500μm) in the gastrointestinal tract of wild barracuda and bass in Bohai Bay. Results revealed that the concentration of small and medium-sized microplastics (0.22~20μm) in the gastrointestinal tract of barracuda ((64.71 ± 80.47) μg/g) was significantly lower than that of bass ((371.30 ± 401.53)μg/g) (P<0.05), while the concentration of large-sized microplastics (20~500μm) ((150.33±116.58) μg/g) was slightly higher than that in bass ((107±96.49) μg/g) (P>0.05). Additionally, the concentrations of PE and PVC were significantly higher than those of PS and PP. Subsequently, the laser infrared imaging system (LDIR) was used to quantify the abundance of microplastics (20~500μm) in the gastrointestinal tract of wild barracuda and bass in the Bohai Bay. It was found that the detected microplastics were mainly 20~50μm in size, primarily fragment-shaped, and mainly composed of 11polymers such as PE and PVC. The average abundance of PP, PE, PS and PVC in the gastrointestinal tract of barracuda ((38.21±19.95) items/g) was slightly higher than that of bass ((34.75±26.33) items/g) (P>0.05). The mass concentration distribution of microplastics in the four materials was generally consistent with the particle abundance distribution. The polymer hazard index was used to evaluate the potential ecological hazards of microplastics in the gastrointestinal tract of bass and barracuda, and it was found that the presence of PVC microplastics led to a higher potential hazard index. Py-TD-GC/MS can detect microplastics with smaller particle sizes in organisms, and the combination of Py-TD-GC/MS and infrared spectroscopy can fully reveal the characteristics of microplastic pollution in wild fish.

This article focuses on the demand side perspective and uses the value chain decomposition method to track the implicit carbon flow composition and path of China's regional information and communication technology industry (ICT industry), and further identify the pollution shelter effect of ICT industry at the regional level The results indicate that the implicit carbon emissions and added value of the ICT industry caused by cross regional trade-related activities dominate, and the shorter the ICT industry production chain in the domestic value chain, the higher the carbon productivity From the perspective of demand categories, the vast majority of domestic provinces mainly generate ICT carbon emissions through local demand (without cross regional trade activities), while foreign regions are mainly caused by cross-border trade activities of final products; The development needs of ICT itself have led to the highest carbon emissions, followed by the construction industry; Fixed capital formation is the largest demand type that leads to implicit carbon emissions in ICT, followed by exports With the increase of cross regional activities, the implicit carbon emissions caused by demand side in the ICT industry have shown a decreasing trend At different stages of the value chain, the role of pollution shelters in each province is heterogeneous, and there are significant differences in their roles when facing different demand areas Based on this, we need to draw an implicit carbon map of the ICT value chain from the demand side, strengthen regional collaborative carbon governance, promote innovative breakthroughs and applications of green and low-carbon technologies in the ICT industry, improve the carbon emission accounting and monitoring system of the ICT industry, and take measures to promote the green and low-carbon development of the ICT industry.

This study investigated the spatial and temporal characteristics of carbon emissions and carbon sinks in the Guanzhong Plain urban agglomeration from 2007 to 2022. In addition, it examined the types of carbon balance across cities within this urban agglomeration. The characteristics of the spatial and temporal dynamics of the carbon balance capacity were described using the ecological support coefficient of carbon emissions, the standard deviation ellipse, and the center of the gravity migration model. The spatial and temporal heterogeneity of the driving factors was explored using a spatial and temporal geographic weighting model. The findings were as follows. Carbon emissions fluctuated and increased from 128,815,700 tons in 2007 to 385,707,600 tons in 2022, with an average annual growth rate of 7.59%. The change in the carbon sink was smaller, increasing from 18,857,800 tons in 2007 to 21,761,100 tons in 2022, with an average annual growth rate of 0.10%. Cultivated land and forestland accounted for 82.56% and 17.01%, respectively, of the carbon sink, which was the main land type affecting the carbon sink level. The spatial difference in the carbon balance capacity was obvious, characterized by high values in the northwest and low values in the east. The standard deviation ellipse revealed a northwest southeast distribution pattern, with the center of gravity shifting eastward. There were significant differences in the driving factors of the carbon balance capacity. The influence of socioeconomic factors such as energy intensity, industrial structure, gross regional product, urbanization level and population density were the most significant, followed by the influence of climatic conditions such as precipitation and temperature. The influence of governance factors such as environmental regulation and green innovation were not significant. This study underscored the importance of developing differentiated strategies from the perspectives of carbon reduction in production and carbon sequestration in ecology.

This study applied the IPCC methodology to estimate carbon emissions in Shanxi Province from 2010 to 2022. A Kaya-LMDI model was employed to identify the key drivers influencing carbon emissions in the region. Using 2022 as the baseline year, the LEAP-Shanxi model was developed to forecast carbon emissions from 2023 to 2060. Economic development acted as the primary driver of carbon emission growth, whereas energy intensity emerged as the dominant restraining factor; By 2060, under four specific scenarios—industrial energy efficiency improvement, low-carbon transportation transition, accelerated new energy adoption, and optimized power structure—energy conservation and carbon reduction effects would become particularly pronounced, these measures could reduce sectoral emissions by 42.16, 3.21, 1.38 and 31.73Mt respectively; Both baseline and integrated scenarios indicate that Shanxi Province could reach its carbon peak by 2030, with projected emissions of 764.33 and 742.34Mt respectively; The comprehensive scenario demonstrates a potential reduction of 107.42Mt in carbon emissions compared to the baseline projections for 2060. These findings can offer a robust theoretical foundation for Shanxi Province to develop targeted low-carbon strategies and implement effective emission reduction measures.

The research explored the evolution trend, spatial correlation network characteristics and driving mechanism of the synergistic effects on carbon reduction, construction waste control, green expansion, and economic growth among different provinces in construction industry from 2010 to 2020 by entropy method, coupling coordination degree model, social network analysis method, and exponential random graph model. The results showed that: The synergistic effect of carbon reduction, construction waste control, green expansion, and economic growth in the construction industry increased from 0.51 to 0.60, gradually transitioning from a barely imbalanced state to a primary coordinated state, with significant spatial heterogeneity. The synergistic effect spatial correlation network presented a "Core-edge" distribution characteristic, and the network density showed an increasing trend, reaching 0.2287 in 2020. The network's dependence on the core region was weak, but the network state had not yet reached optimal state, and there was still significant for improvement, such as Henan, Hunan, Shaanxi, and Xinjiang were in a dominant position in the internet and had apparent "Matthew effect". Hebei, Anhui, Jiangxi, and Henan provinces had shown significant "Siphon effect". Heilongjiang, Jilin, Liaoning and other provinces played the role of peripheral actors in the network. Most of the spatial correlations of the synergistic effects of carbon reduction, construction waste control, green expansion, and economic growth in the construction industry were concentrated within blocks rather than between blocks. The developed eastern region was mainly the "Net profit" block, while the central and western regions were the "Two-way spillover" blocks. Hunan, Shaanxi, Hubei and other provinces occupied the network structure holes position and had obvious advantages in the construction of synergistic effects. The significant driving force of endogenous network structure was the formation process of the synergistic effect network. The factor of the proportion of construction industry output value/GDP strengthened the spatial correlation between the synergistic effects. The proximity of geographical locations helped to promote the formation of a basin collaborative governance network. Thus, targeted policies for carbon reduction, construction waste control, green expansion, and economic growth in the construction industry should be formulated based on the characteristics of different regions to promote high-quality development of the regional construction industry.

This study systematically reviews bioenergy with carbon capture and storage (BECCS) technology pathways based on various biomass conversion technologies. Using the Life Cycle Assessment (LCA) framework, it identifies the key processes in the BECCS life cycle and provides a comprehensive review of the negative emissions potential and environmental impacts of different BECCS technology pathways. The results indicate that BECCS pathways based on biomass direct combustion, gasification power generation, and biomass gasification for hydrogen production exhibit strong negative emissions potential. However, due to differences in technology types, technical parameters, and assumptions, the negative emissions potential of the same type of technology in existing studies varies significantly. Moreover, while the water consumption, energy consumption, and other environmental impacts of BECCS have gained attention, there is still no consensus on its comprehensive environmental impacts. At present, the evaluation of the negative emissions potential and life cycle environmental impacts of BECCS is still in its early stages, lacking standardized assessment frameworks and reliable full-chain data. Furthermore, no consistent conclusions have been formed for evaluating different BECCS technology pathways. It is imperative to conduct further research to support macro-level planning for carbon neutrality pathways.

Develop a net carbon sequestration accounting model for rice production and estimate the net carbon sequestration across 30 provinces in China from 2000 to 2021. Building on an understanding of its spatiotemporal dynamics, the study employs the coupling coordination model and the Tapio decoupling model to assess the degree of coupling coordination and the evolution of the coupling state between net carbon sequestration and rice output value. The results are as follows: (1) Overall, net carbon sequestration in China's rice production demonstrates a fluctuating upward trend, increased from 6634.50×10⁴t in 2000 to 7990.81×10⁴t in 2021. with notable spatial heterogeneity—higher values in the eastern regions and lower values in the west. The centroid of net carbon sequestration has shifted from the southwest to the northeast. (2) While there is spatial correlation in net carbon sequestration, the spatial agglomeration effect has diminished over time. The global Moran's I index shows a two-phase pattern, characterized by a "steady decline followed by stable fluctuations," with 2010 marking the transition point. (3) The coupling coordination degree between net carbon sequestration in rice production and rice output value across the 30 provinces follows a "decline followed by increase" trend. (4) In most years, the coupling relationship between net carbon sequestration and rice output value is generally favorable, with a gradual improvement in coupling effects. However, significant variability in the coupling status exists across different rice production regions and provinces.

Based on panel data from 30 provinces in China from 2011 to 2021, this paper uses the coupling coordination degree model, local spatial autocorrelation analysis, and system GMM regression method to systematically examine the spatiotemporal evolution characteristics and influencing factors of the coupling coordination level between China's new quality productivity and carbon emissions. The study found that the annual average of the new quality productivity index increased from 0.1 to 0.23, and the carbon emission intensity decreased from 2.548 to 1.942, indicating a continuous improvement in the synergy level between the two. The coupling coordination degree shows a gradient differentiation of "high in the southeast and low in the northwest". Eastern coastal provinces have risen to high-quality coordination based on digital economy and green technology innovation, while northern energy bases have long been in low value agglomeration due to the "high carbon low efficiency" path dependence. Economic development, opening up to the outside world, and innovation levels significantly promote the improvement of coordination, while environmental regulations have a restraining effect due to the "compliance cost squeeze". Regional heterogeneity analysis shows that the eastern region strengthens technology spillover through global value chain embedding, the northeast is constrained by structural contradictions in heavy industry, and the western region suppresses innovation diffusion due to geographical decline and lagging infrastructure.

Taking the residents in North China as research subjects, the study employed an air quality satisfaction assessment and indicator system to analyse the patterns of air pollution and residents' satisfaction with air quality during both the heating and non-heating seasons. It also examined the factors influencing residents' satisfaction with air quality in North China. The findings revealed that the air quality satisfaction scores for residents were 72.15 during the heating period and 72.62 during the non-heating period, indicating a level of "relatively satisfied". A significant negative correlation was found between the satisfaction index and PM_2.5 levels during the heating period, and a similar negative correlation with PM₁₀ levels during the non-heating season, demonstrating a good model fit. The indicator system showed that public expectations, perceived value and public trust were significantly influenced by heating conditions: public expectations during the heating period were significantly lower than those during the non-heating period; perceived value during the heating period was significantly higher than that during the non-heating period; and public trust during the heating period was significantly lower than that during the non-heating period. Particulate matter pollution remained an important factor affecting residents' satisfaction with air quality in North China. Furthermore, residents' satisfaction with air quality was influenced by multiple factors such as education level, age, and information transparency. Therefore, in future air quality management policies, the government should continue to focus on issues such as PM_2.5 emissions control, air pollution from centralized heating in winter, and the dust management in Inner Mongolia.

Using methods such as composite index evaluation, probabilistic risk characterization, and multi-attribute decision-making, this study investigates the governance challenges posed by multiple risk sources, diverse receptors, and complex exposure pathways in urban ecological environments. It systematically analyzes the transition of risk sources from natural to anthropogenic and from single to multiple origins, as well as the expansion of risk receptors from human health to broader domains such as socio-economic systems, along with the corresponding evaluation indicators. The results show that integrated assessment models can overcome the limitations of single-method approaches by combining information across ecological, socio-economic, and public health dimensions. These models offer a holistic perspective to effectively address complex risk issues and represent a crucial direction for large-scale urban ecological risk assessments, providing scientific support for sustainable urban development and risk management decision-making.

Based on the statistical data of environmental emergencies directly dispatched by the Ministry of Ecology and Environment from 2005 to 2022, this study used the standard deviation ellipse and mean center to explore the spatiotemporal variability of environmental emergencies, the results showed that the total quantity of environmental emergencies in China exhibited a downward tendency. The spatial mean center of environmental emergencies moved to the southwest of China, spanning a total distance of 734 kilometers in the past 17years, Hubei and Shanxi provinces had replaced Zhejiang, Guangdong and Jiangsu provinces as new high-incidence regions. Through the analysis of the characteristics of environmental emergencies, including the causes, pollution media and pollutants, it is found that production safety accidents were the primary cause of environmental emergencies, accounting for 45.12% of the total, followed by traffic accidents, which had surpassed production safety accidents in proportion over the past two years. Water pollution incidents were the most frequent environmental emergencies, and among the particularly major and the major environmental emergencies, water pollution incidents accounted for about 77.55%. Petroleum and heavy metals were two common pollutants in environmental emergencies, accounting for 16.31% and 5.88% of the total incidents, respectively. In the major and above level environmental emergencies, the proportion of heavy metals was higher than that of petroleum.