This study focused on the plant-microbe combined remediation system involving Bacillus megaterium and Celosia argentea L., to explore the impact of Bacillus megaterium on the succession of the rhizosphere microbial community and its role in the remediation of cadmium-contaminated soil. High-throughput sequencing analysis was conducted to examine the structural changes in the rhizosphere microbiota of Celosia argentea at different time points (7th, 21st, and 50th days). The results indicated that in the treatment group, inoculated with B. megaterium, the number of OTUs, diversity indices (Shannon, Simpson), and richness indices (Chao1, Ace) of the microbial community were all higher than those in the control group by the 50th day; the Acidobacteriota, Chloroflexi, Proteobacteria, and Bacteroidetes were the core groups within the microbial community; B. megaterium was able to dominate the rhizosphere microbial community in the early stages but its relative abundance gradually declined from 12.01% to 1.17% over the 50days; Functional prediction of the soil microbial community showed that B. megaterium mainly promoted the C and N cycle within the microbial community, potentially exerting a positive influence on the functionality and stability of the microbial community; B. megaterium significantly increased the cadmium content in the leaves of C. argentea and the bioavailable cadmium content in the rhizosphere soil by 40.3% and 17.6%, respectively. This study provides a theoretical foundation and empirical data support for optimizing plant-microbe combined remediation techniques and understanding the succession patterns of microbial communities in plant-microbe combined remediation systems.

The present study was aimed to quantitatively estimate the odor emission of municipal solid waste landfills in the loess area of Northwest China and investigate the technical feasibility of using loess soil as covering material for odor pollution control. For this purpose, the study was conducted in field and chose four types of landfill surface sources representing different periods and different coverage states in this region. The surface odor release rates were determined as follows: 5915µg/(m²·h) for newly formed landfill surface without cover, 122µg/(m²·h) for newly formed landfill surface with loess cover 757µg/(m²·h) for loess-covered surface after 5months, and 14057µg/(m²·h) for re-exposed landfill surface. The results indicated that the loess cover reduced odor emissions by more than 94% at two periods and effectively controlled various odor compounds. The analysis on the loess microbial community structure after 5 months of coverage showed that Actinobacteria had the highest relative abundance, potentially participated in the degradation of volatile organic compounds, and had a stronger effect on the surface. The experimental results demonstrated the effectiveness of loess cover in controlling odor emissions, proving that the application of loess as a landfill cover layer is feasible in the northwest region.

Heterogeneous catalytic ozonation (HCO) was used to degrade organic pollutants in water via both direct oxidation and reactive oxygen species (ROS) converted from ozonation. In general, the physicochemical catalysts properties were considered as an important factor that influenced the wastewater purification efficiency. Being attributed to stable chemical properties, easily regulated surface properties and pore structures, carbon-based materials for HCO arose much attention in wastewater treatment. Herein, the research progress and application of carbon-based catalysts for HCO in wastewater treatment were systematically discussed, which helped reader make a complete view. Furthermore, the functionalization and regulation methods of commonly used carbon-based catalysts were introduced in details, and the relationship between carbon-based materials structure and ROS generation was deeply discussed. Meanwhile, organic pollutants degradation mechanisms via radical and non-radical reaction under different reaction conditions such as water quality were expounded. Finally, the prospection and development of carbon-based materials for HCO in wastewater treatment was proposed. The results showed that carbon-based materials for HCO have broad application prospects in wastewater treatment. Future research should focus on the optimization of catalysts and the in-depth exploration of practical applications.

Sludge from pharmaceutical wastewater treatment plants serves as a major reservoir for antibiotics. This study aimed to investigate the residual characteristics of antibiotics in sludge from different stages of wastewater treatment under varying production loads, and to assess the potential ecological risks of physicochemical and biochemical dewatered sludge using the Risk Entropy(RQ) method. The results indicated that 11 types of antibiotics were detected in the sludge under both high and low production loads, with total detected concentrations of 401.72µg/kg and 55.02µg/kg, respectively, showing significant differences in concentrations among different antibiotics. The production load had a notable impact on the wastewater treatment process. Principal component analysis(PCA) delineated robust disparities in antibiotic concentrations and water quality parameters among various treatment stages, with these differences being more pronounced under high production loads than under low production loads. Furthermore, redundancy analysis (RDA) underscored the substantial influence of distinct wastewater quality parameters on the removal efficacy of antibiotics. Residual levels of antibiotics from pharmaceutical processes remained relatively high in both physicochemical and biochemical dewatered sludge, with elevated concentrations of 9.39µg/g in low production load physicochemical sludge and 12.91µg/g in high production load biochemically dewatered sludge. Erythromycin, roxithromycin, and sulfamethoxazole in sludge-amended soil posed a high risk (RQ>10) to aquatic organisms in the receiving environment, with sulfadimethoxine exhibiting the most pronounced environmental risk (RQ>295.04). Macrolides and sulfonamide were identified as the primary risk factors in pharmaceutical plants, and it is recommended that these be prioritized for pollution control. The ecological risk posed by mixed antibiotics was significantly higher than that of individual antibiotics. Therefore, careful consideration of the final disposal of both physicochemical and biochemical sludge is crucial.

The particle number concentration and size distribution of combustion emissions from seven types of honeycomb briquettes and eleven types of lump coal were investigated using a Scanning Mobility Particle Sizer (SMPS) in a laboratory-simulated combustion setup with a dilution channel sampling system. Emission factors for the number concentration of various particle size segments were calculated, yielding essential data for the construction of a number concentration inventory and the enhancement of effect simulations. The results indicated the following: A significant quantity of submicron particles was emitted during the combustion processes of both coal types. The number concentrations exhibited a decreasing trend with increasing particle size, notably in the nucleation and Aitken modes. However, this decreasing trend was less pronounced in the lower particle size section of the accumulation mode (100nm ≤ Dp ≤ 200nm), while the number concentration of larger particles (200nm ≤ Dp) gradually increased with increasing particle size. The total number concentration emission factors from the combustion of honeycomb briquettes and lump coal were determined to be 9.9×10¹⁴±5.3×10¹⁴ particles/kg and 1.4×10¹⁵±7.9×10¹⁴ particles/kg, respectively. For lump coal, the emission factors across the three modes of combustion emissions were calculated as 1.0×10¹⁵±5.9×10¹⁴ particles/kg, 2.8×10¹⁴±2.5×10¹⁴ particles/kg, and 6.4×10¹³±3.5×10¹³ particles/kg. Notably, the three-modal mean concentration emission factors for lump coal were 1.3, 1.9, and 1.5times higher than those for honeycomb briquettes. Furthermore, the ICRP computational model was employed to estimate the total respiratory deposition flux (RDF) ranges of 7.6×10¹² to 4.7×10¹³ particles/min for honeycomb briquettes and 5.7×10¹² to 3.3×10¹³ particles/min for lump coal. It was found that over 90% of the RDF was attributed to the nuclear mode particles when compared to Aitken mode particles in the combustion emissions of submicron particles within the respiratory tract. Additionally, the particle RDF size distribution exhibited a decreasing trend across all three regions of the respiratory tract. Overall, this study provided a comprehensive analysis of particle number concentrations, size distributions, emission factors, and inhalation exposures associated with particulate matter from civil coal combustion emissions across different particle size sections. The findings contribute valuable data and essential support for the development of numerical concentration inventories, improvements in effect simulations, and assessments of health risks.

As a kind of complex polar organic compounds commonly existing in the atmosphere, dissolved organic carbon (DOC) in precipitation has extensive and far-reaching influences on regional ambient air quality, global climate change and carbon cycle process, and has become one of the hot spots in current global change research. This article systematically summarized the research progress on atmospheric precipitation DOC in recent decades both domestically and internationally from three aspects: the abundance and bioavailability of DOC in atmospheric precipitation, the spatial and temporal distribution characteristics and influencing factors of DOC concentration and wet deposition flux in precipitation, and the ecological and environmental effects of DOC wet deposition. In the end of the article, the future development direction was discussed. The results indicated that the chemical composition of precipitation DOC is exceptionally complex, mainly composed of low molecular weight organic acids, amino acids and urea, etc. with high bioavailability. There were significant spatiotemporal differences in precipitation DOC concentration and wet deposition flux among different areas, which were mainly controlled by emission sources, emission intensity, and complex weather conditions. The DOC in the atmosphere could affect the properties of aerosols and precipitation (acid rain), and DOC settling on the surface of snow and ice could accelerate the melting of glaciers. At the same time, the input of DOC brought by wet deposition can enrich the organic carbon levels on the surface of seawater. Active DOC can promote the improvement of secondary productivity in marine ecosystem, while refractory DOC could contribute to the refractory dissolved organic carbon pool in the ocean, which is conducive to carbon sequestration and enhances ocean carbon sinks, helping to achieve the goals of "Ocean Negative Carbon Emissions" and "Carbon Neutrality". Future research should continue to focus on developing and using advanced instruments and equipment to accurately identify and quantitative the chemical composition of precipitation DOC, to have a deeper understanding of the bioavailability/inertness characteristics of precipitation DOC. At the same time, new numerical simulation techniques should be developed and utilized to conduct in-depth research on the spatiotemporal heterogeneity of atmospheric DOC wet deposition fluxes with different properties of on the global scale, and quantify the indirect wet deposition flux of atmospheric DOC. On this basis, elucidating the significance and value of atmospheric DOC wet deposition as one of the new pathways for improving global ocean carbon sequestration, so as to gain a deeper understanding on the position and role of atmospheric deposition in global carbon cycling and ocean “missing carbon sink” research.

The influence of solar radiation, climate, soil, and vegetation on the vapor pressure deficit (VPD), as well as the characteristics of its spatiotemporal heterogeneity under the effects of its interaction with the terrestrial-atmospheric system, were explored using spatiotemporal trend analysis, geodetector, and geographical and temporal weighted regression (GTWR) models. The results showed that the multi-year average VPD value for the Jizi Bay of the Yellow River from 1982 to 2021 was 0.785kPa, with the highest annual VPD value found in the northwestern part of the area, followed by the central and western parts. Interannual and seasonal VPD showed a significant increase in all regions (P<0.05), with the highest increase in summer VPD [0.072kPa/10a] and a high increase in mean annual VPD in the east [0.045kPa/10a]. On the interannual scale, moisture conditions (precipitation and soil moisture) had the strongest influence on VPD, followed by temperature; in the southeast, NDVI had a strong influence on VPD. Additionally, the interaction of precipitation and temperature had the strongest influence on VPD, followed by the interaction of deep soil moisture with precipitation, temperature, and vegetation indices. On the spatiotemporal scale, from the 1980s to the 2010s, the limiting effects of precipitation and vegetation indices on VPD were gradually enhanced over time from the northwest to the southeast of the region. Furthermore, the promoting effects of temperature on VPD gradually increased with time from the south to the north, while the limiting effects of deep soil moisture on VPD gradually weakened with time from the southeast to the northwest. The results of this study provide a scientific basis for revealing the process of land–atmosphere interaction in this region and promoting the ecological protection and high-quality development of the Yellow River Basin.

Halogenated organic compounds (HOPs), as important industrial chemicals, are extensively released into the environment during their production, transportation, and usage, ultimately accumulating in waste activated sludge (WAS) from wastewater treatment plants. Anaerobic digestion is a crucial approach for resource recovery from WAS, converting organic matter into valuable products such as volatile fatty acids and methane. However, the effects of HOPs on the anaerobic digestion capacity of WAS and their underlying mechanisms have not been systematically elucidated. Through a comprehensive literature review, this study analyzed the impacts of HOPs on methane production efficiency, key processes, and microbial communities during sludge anaerobic digestion. The results revealed that most HOPs inhibit key stages of anaerobic digestion due to their high toxicity, leading to reduced methane yield, while some low-toxicity HOPs exhibit a "hormesis effect" with promotion at low concentrations and inhibition at high concentrations. HOPs primarily regulate anaerobic digestion efficiency by affecting four critical stages: solubilization, hydrolysis, acidogenesis, and methanogenesis, with the most significant impacts on acidogenesis and methanogenesis. HOPs can influence the function of anaerobic microorganisms by altering microbial community structure, inhibiting key enzyme activities, and interfering with metabolic pathways. This study unveils the mechanisms of HOPs’ effects on sludge anaerobic digestion and proposes future research directions addressing current knowledge gaps, providing a theoretical foundation for resource recovery and safe disposal of WAS.

In this study, the pollution of direct and leakage in Shiwuli River was analyzed by combining anionic surfactant sodium dodecyl benzene sulfonate (SDBS) and dissolved organic matter (DOM) traceability methods, and the correlation and difference of each index were studied by Pearson correlation analysis method. The results showed that the content of SDBS in untreated domestic sewage was high (522~668µg/L), which was easily affected by industrial washing wastewater when characterizing the pollution situation. DOM is characterized by high percentage of CHOS compounds (83%~84%), protein + lipid components (80%~81%), high hydrogen-carbon ratio (H/C=1.6) and low-carbon nominal oxidation state (NOSC=-1) in untreated domestic sewage. Combining the advantages of SDBS and DOM traceability can effectively eliminate interference factors and make the characterization of river domestic sewage pollution more reliable. This study can provide new ideas and technical support for the analysis and traceability of the direct and leakage of domestic sewage pollution in rivers.

To deeply understand the nitrogen cycling process in alpine forest small watersheds in the northeast of the Tibetan Plateau, the throughfall, soil water and surface runoff at two alpine forest sites in Datong and Huangyuan in the Hehuang Valley in the Tibetan Plateau were studied from April to September 2022. The concentration and flux of dissolved inorganic nitrogen (DIN) were monitored, and the distribution characteristics of nitrogen and oxygen (N and O) isotopes of nitrate (NO₃⁻) along the hydrological path (from throughfall to soil water and then to surface runoff) was analyzed via stable isotope technology. The results showed that the average nitrogen deposition in Datong and Huangyuan (3.60kg/(hm²·a)) was higher than that in the Tibetan Plateau (2.94kg/(hm²·a)), and the nitrogen deposition in Huangyuan (4.17kg/(hm²·a)) was higher than that in Datong (3.02kg/(hm²·a)). The average concentration of NO₃⁻ in soil water at the two alpine forest small watersheds was 5.78mg/L. The average δ¹⁸O-NO₃⁻ ((−1.54±9.77)‰) in soil water was lower than that in throughfall ((74.2±0.01)‰), indicating that nitrification occurred in alpine forest soil. Over 90% of the NO₃⁻ in soil water was from soil nitrification using the end member model analysis, and the remaining approximately 10% might be came from atmospheric deposition. The average concentration of NO₃⁻ in surface runoff at the two alpine forest small watersheds was 5.73mg/L. The δ¹⁸O-NO₃⁻ and δ¹⁵N-NO₃⁻ in surface runoff were enriched along the growth trend of 1:2, indicating that a denitrification process occurred in surface runoff. The δ¹⁵N-NO₃⁻ and δ¹⁸O-NO₃⁻ in the Tibetan Plateau alpine forests decreased from throughfall to soil water, and then increased from soil water to surface runoff.