Microplastics (MPs) pollution has become a hot research topic in the environmental field, while few studies have reported the MPs pollution in the gastrointestinal tract of river fish in Hainan Island. In the present study, 222 freshwater fish specimens belonging to 35 species with different feeding habits were collected from 11 sampling sites located in the upper, middle, and lower reaches of the Nandu River. The pollution characteristics of MPs in the gastrointestinal tract of fish samples were analyzed. The results showed that MPs were detected in 94.5% of the fish gastrointestinal tracts, with an average abundance of (4.85±3.51)MPs per fish. The MPs in fish gastrointestinal tract were dominated by <1.0mm (73.3%) transparent (38.9%) fibers (60.6%), and were mainly composed of polypropylene (53.3%) and polyethylene (34.2%). The highest abundance of MPs was recorded in the gastrointestinal tract of filter-feeding planktivorous fish (7.00 per fish) and the lowest abundance was recorded in the gastrointestinal tract of insectivorous fish (2.57 per fish). From the upper to the lower reaches, the percentage of blue fragment MPs with size <1.0mm in the fish gastrointestinal tract was increasing, while the percentage of yellow/red fiber/film MPs with size >1.0mm was decreasing. This could be attributed to the increase of aquacultural activities, the usage of agricultural films, and a large amount of sewage and industrial wastewater in the lower reaches.

In order to address the issues of complex processes and high infrastructure and operational costs in simultaneous nitrogen and phosphorus removal, a heterotrophic nitrifying strain NP3 exhibiting simultaneous nitrogen and phosphorus removal capabilities was isolated from activated sludge in this study. Strain NP3 was identified as Pseudomonas stutzeri by 16S rRNA sequence analysis, and its nitrogen and phosphorus removal characteristics and mechanisms were investigated. It was showed that strain NP3 was able to utilize ammonium, nitrate, and nitrite as the sole nitrogen source for efficient nitrogen and phosphorus removal under aerobic conditions. The accumulation of intermediate products during the reaction process was minimal, and nitrogen and phosphorus were primarily removed through assimilation. The growth and metabolic rates followed the order: NH₄⁺-N >NO₂⁻-N >NO₃⁻-N. Under the optimal growth conditions of sodium citrate as the carbon source, C/N=10, T=30℃, pH =7, and r=160r/min, the maximum removal rates of ammonia nitrogen and phosphate were almost 100%. Furthermore, successful amplification of denitrification and polyphosphate genes (nosZ, nirS, ppk) further confirmed the simultaneous nitrogen and phosphorus removal capability of strain NP3. X-ray Photoelectron Spectroscopy (XPS) analysis demonstrated that the functional groups on the extracellular polymeric substances(EPS) surface could adsorb different forms of phosphorus such as C-PO₃/P-C, PO₄^3-/HPO₄^2-, acting as phosphorus transfer stations.³¹P nuclear magnetic resonance (NMR) results further indicated that there was a large effect of EPS on phosphorus fugitive morphology, with pyrophosphate being the main phosphorus species in the presence of EPS, whereas orthophosphate and orthophosphate diester were the major phosphorus forms after EPS extraction.

The catalytic degradation mechanism of petroleum hydrocarbons by Ferripyochelin (FerriPCH), formed by the combination of pyochelin (PCH) from the extracellular fluid of P. aeruginosa NY3 and Ferri, was investigated. The results showed that two chiral PCHs were produced by strain NY3. The purified PCH could degrade both alkanes and polycyclic aromatic compounds of petroleum hydrocarbon after combining with Ferri. A certain ratio of hexadecane, anthracene, as well as phenanthrene could be degraded by FerriPCH which formed by PCH and Ferri in the ratio from 2:1 to 1:1. In addition, degradation efficiency of aromatic hydrocarbons with low bio-availability was significantly higher than that of alkanes. Further studies showed that strongly oxidizing free radicals of •OH and •O₂^- produced after the binding of Ferri and PCH degraded petroleum hydrocarbons into carbon dioxide and water step by step.

Against the backdrop of China entering a new stage of development, implementing new development concepts, and building a new development pattern, how to pursue healthy industrial development while controlling water energy consumption and reducing carbon emissions has become an important and urgent practical task. On the base of exploring deep level industrial economic connections, the theoretical framework of the three-dimensional full footprint stereoscopic correlation of industry water energy carbon was constructed. Then the article designed an input-output calculation model for industrial factor footprints and created a function correction input-output table to solidify the data foundation. Selecting Chinese industries from 2002 to 2022 as the research object, the three-dimensional full footprint of industrial water, energy, and carbon were calculated. Based on the three dimensional full footprint stereoscopic correlation network of water energy carbon in Chinese industries, the evolution characteristics of network attributes and relationship structures have been compared and analyzed by combining dynamic and static methods. The results showed that:(1) During the research period, the average annual growth rate of China's industrial water, energy, and carbon total carbon footprint had decreased, but the total amount had increased significantly. The increase in water footprint was mainly due to the increase in industrial direct footprint, while the increase in energy footprint and carbon footprint were due to the increase in industrial indirect footprint. (2) There were significant differences in the three-dimensional footprint of water energy carbon and dual factor among various industries, and it was necessary to integrate the characteristics of industries and footprint characteristics to improve the efficiency of factor utilization. (3) During the research period, various indicators and coupled performance of the industrial water energy carbon network had improved, but the circular sustainability, symbiosis and mutual benefit, and correlation had not reached the ideal state.

To promote the reduction and recycling of construction and demolition (C&D) waste in housing, a dynamic material flow model was established to simulate the evolving characteristics of housing flow-stock in both urban and rural areas of Beijing from 1949 to 2100. The amount of urban and rural housing C&D waste generated was predicted. The results showed that from 1949 to 2100, cyclical fluctuations were observed in the volume of new construction and demolition of housing in Beijing’s urban and rural areas, with the housing stock following an S-shaped curve. The area of new housing construction in urban and rural regions peaked at 31.456million m² in 2012 and 7.887 million m² in 2015, while the demolition area reached its maximum of 15.008 million m² in 2094 and 4.535 million m² in 2016. The saturation values of housing stock in urban and rural areas were 800 and 1.247 million m², respectively. By the mid-to-late 21 st century, Beijing was anticipated to experience a surge in C&D waste generation, which will reach its peak and then persist at elevated levels with periodic fluctuations. The apex of C&D waste generation was projected to occur in 2094, with an estimated total output of 23.964 million tons. Cement, brick, sand, and gravel were the predominant components of C&D waste by weight, accounting for 90.2%~95.5% of the total weight of housing C&D waste in urban areas and 92.2%~94.1% of that in rural areas, while the weight proportion of iron and steel ranged from 0.1% to 4.5% and 0.1% to 3.0%, respectively. The long-lifetime scenario could defer the peak of C&D waste, with a maximum reduction potential of 72.0%. Additionally, recycling C&D waste as urban minerals could lead to a dramatic decrease in future demand for primary steel, with a reduction of up to 98.5%.

This study applied umbrella-shaped modified basalt fiber (MBF) bio-carrier to an integrated fixed-film activated sludge system to investigate the performance of MBF bio-nest in wastewater treatment and N₂O emission reduction. The effect of dissolved oxygen (DO) on N₂O reduction in the bio-nest was investigated by changing the DO concentration. The results showed that under the same operating conditions, TN removal efficiency was increased by 63.87% and N₂O emission was reduced by 77.76% in the bio-nest system compared with the sequencing batch activated sludge bioreactor. According to the 16sRNA sequencing results, a variety of functional microregions existed within MBF bio-nests, with a high diversity of microbial populations. Saccharibacteria genera incertae sedis were the main carbon-removing bacteria in the reactor, and heterotrophic nitrification-aerobic denitrification(HN-AD) genera were the main nitrifying bacteria, which did not emit N₂O during the nitrification process. Denitrification genera were dominated by conventional heterotrophic denitrification bacteria (HDN) in the inner and middle layers of the bio-nest (17.42%,23.02%), and HN-AD bacteria in the outer layer of the bio-nest and suspended sludge (29.70%, 27.53%). Aerobic/anoxic/anaerobic genera were distributed in all layers of the bio-nest, and denitrification genera had higher relative abundance in the MBF bioreactor than in the SBR, which facilitated denitrification and mitigated the accumulation of intermediate products, reducing N₂O emissions. The MBF bio-nest reactor had the highest TN removal rate of 86.64%±1.14% and the lowest N₂O emission of (0.78±0.83) mg N₂O/g TN when the DO concentration was 2.5mg/L (M2). The bio-nest microbial genus categories were basically the same in each DO gradient, but differed in their relative abundance. In M2, HN-AD bacteria were the main nitrifying functional bacteria in the reactor(the relative abundance of the layers from inside to outside was 44.24%, 61.34%, and 36.16%), which was conducive to N₂O reduction; HDN were the main functional bacteria in the M2reactor, with moderate relative abundance of 20.17%, 12.00%, and 21.20% from inside to outside layers; the concentrations of NO₂^--N and NO₃^--N in the effluent were (0.011±0.002) and (1.65±0.46)mg/L; denitrification was carried out completely, which was conducive to the reduction of N₂O emissions.

The co-pyrolysis of biomass/sewage sludge was demonstrated to facilitate efficient resource utilization, harmless treatment, and sludge volume reduction. Due to the complexity of co-pyrolysis reactions, it was deemed essential that the thermodynamic properties and product distribution of this process be systematically evaluated. The pyrolysis characteristics, synergistic effects, and product distribution of municipal sludge-peanut shell mixtures were investigated using thermogravimetric analysis and a fixed-bed reactor. It was observed that significant synergistic interactions were exhibited during municipal sludge/peanut shell co-pyrolysis, primarily during the volatile release stage, where the synergistic effect was found to accelerate mixture pyrolysis. When the conversion rate (α) was below 0.7, the apparent activation energy was progressively reduced with increasing sludge mass ratio(SMR). Conversely, when α exceeded 0.7, the apparent activation energy sharply increased with higher SMR. The gas yield was enhanced with elevated pyrolysis temperatures, while liquid and solid yields were significantly diminished. Elevated temperatures were also shown to promote H₂ and CH₄ generation. Product yields and synergistic effects were strongly influenced by SMR, with the most pronounced co-pyrolysis synergy observed at an SMR of 40wt.%.

The seasonal vertical distribution of aerosols in the southern margin of the Taklamakan Desert was analysed using aerosol LiDAR data from the Minfeng meteorological station from June 2023 to May 2024, and the HYSPLIT backward trajectory model was employed to identify the transport paths of aerosols at different altitude layers. Finally, the vertical distribution of aerosols and their transport paths at different stages of dust pollution are analysed by taking a dust pollution event as an example. The results show that: ①The dust aerosols can be lifted up to a maximum height of 3~4km (4.4~5.4km above sea level) above the ground surface, which is comparable to the average elevation of the Tibetan Plateau (>4km), and suggests the possibility of transport of dust aerosols from the study site to the outside of the Tarim Basin. ②The extinction coefficients of the four seasons show a decreasing trend with height in the vertical direction, and the maximum values are all located at the low altitude of 150m. The highest values are found in spring (0.69km^-1, 0.20), followed by winter (0.52km^-1, 0.18) and summer (0.40km^-1, 0.16), and the lowest values are found in autumn(0.25km^-1, 0.11). ③The dust aerosols are mainly affected by the east-west transport, except for the 1500 and 3000m altitude layers in winter which are affected by the westerly transport, the 500, 1500 and 3000m altitude layers in the rest of the seasons are affected by the northeasterly and westerly transport at the same time. ④The extinction coefficients carried by the northeasterly jet are significantly higher than those carried by the westerly jet at different altitudes in all seasons, making the northeasterly jet the main dust transporting jet. ⑤The study of a dust pollution event shows that the extinction coefficient of the near-surface aerosols is greater than 1km^-1, the depolarization ratio exceeds 0.3, and the vertical trend is decreasing with height during the dust pollution process. The northeastern airflow in the Tarim Basin is the main transport airflow for dust aerosols during this dust event.

Accurately assessing the degradation status of seagrass bed ecosystems was essential for formulating effective protection and restoration decisions However, existing assessments of seagrass bed ecological degradation were primarily conducted from the health perspective, neglecting the endpoint of degradation and its critical levels during the degradation process. This study took ecosystem collapse as the endpoint of degradation and, from an ecological risk perspective, the assessment framework of the Red List of Ecosystems was drawn upon. Three main criteria—habitat range degradation, abiotic environmental degradation, and biological process degradation—were integrated to establish an assessment framework for seagrass bed ecosystem degradation. Fourteen seagrass bed distribution areas along the South China coast were selected for empirical study. The assessment results showed that the seagrass bed in Tangjiawan had reached an extremely degraded level. Eight seagrass beds, such as Zhelin Bay, were severely degraded (57%); the seagrass bed in Li'an Port was moderately degraded; and four seagrass beds, such as Liusha Bay, were slightly degraded (29%). Among the three major assessment criteria, biological processes were identified as the main manifestation of seagrass bed degradation along the South China coast. From the perspective of ecosystem collapse risk, a framework for assessing seagrass bed ecosystem degradation was constructed, providing a new perspective for evaluating the degradation status of seagrass beds and other ecosystems, and offering important decision-making support for ecosystem conservation and restoration.

The solid-phase extraction method and the thermal-optical method were combined to obtain different polar HULIS and the carbon content of HULIS (HULIS-C) in PM_2.5 with high temporal resolution during the heavy pollution event in Xi'an. The light absorption characteristics of HULIS were analyzed using a UV-Vis spectrophotometer equipped with a liquid waveguide capillary cell (LWCC), and the positive matrix factorization model (PMF) was used to analyze the sources of HULIS. At the same time, the source of HULIS is combined with the positive matrix factorization model (PMF). The results showed that the average mass concentration of neutral HULIS (HULIS-n) (6.6±2.6)µg/m³ was higher than that of acidic HULIS (HULIS-a) (3.7±3.5)µg/m³, accounting for approximately 30% and 18% of OC, respectively, indicating severe HULIS pollution during heavy pollution periods. The absorption coefficients (AAE, E₂/E₃, and MAE₃₆₅) of HULIS-n were all greater than those of HULIS-a, suggesting that HULIS-n contains more conjugated and aromatic structures and has stronger light-absorbing properties, with a more significant impact on atmospheric visibility. The source analysis revealed clear differences in the contributions of HULIS-n and HULIS-a. The primary sources of HULIS-n included secondary sources, coal combustion, motor vehicle emissions., while the contributions of secondary sources and coal combustion were higher for HULIS-a.