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.%.

A new block filter material with well-developed pores and stable chemical properties was prepared from a biomass ash by short-term and high-temperature sintering. The phosphorus adsorption properties, as well as the kinetics and thermodynamic behaviors, of this material were investigated in this paper. The results of the static adsorption experiments show that the biomass ash filter achieved higher phosphorus adsorption per unit under conditions of higher initial phosphorus concentration, higher reaction temperature, longer adsorption time, or lower solid-liquid ratio. Among these parameters, the solid-liquid ratio was the primary controlling parameter affecting phosphorus adsorption by the filter material. The maximum adsorption per unit of the filter material reached 7.72mg/g, when the initial concentration of phosphorus was 90mg/L, the reaction temperature was 55℃, the adsorption time was 1250min, the pH was 3, and the solid-liquid ratio was 1:200(g:mL). The surface of the material exhibited a heterogeneous structure, and its phosphorus adsorption was primarily driven by multilayer physical endothermic adsorption, supplemented by monolayer or multilayer spontaneous chemical adsorption. Under the dynamic adsorption conditions, the phosphorus adsorption capacity of this filter material per unit was 9.8, 22.27 and 27.22 times that of three common commercial filter materials, including coconut shell biochar, ceramsite and natural zeolite, respectively. This indicates excellent adsorption properties, enabling water purification while achieving biomass ash disposal and recycling, making it highly valuable for promotion.

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%.

Earthworm (Pheretima guillelmi) was selected as the model animal. Combination of in situ determination, high-throughput sequencing and biochemical analysis, the results indicated that the production of Fe(Ⅱ) was highest in the glucose treatment group and lowest in the amino acid setup. During the iron(Ⅲ) reduction process, the content of surface-adsorbed Fe(Ⅱ) was the highest, ranging from 0.6 to 24.38mmol/L;whereas the content of ionic Fe(Ⅱ) was the lowest, ranging from 0.02 to 2.21mmol/L. The community structure of iron(Ⅲ)-reducing bacteria was significantly influenced by the type of organic matter, and the dominant iron(Ⅲ)-reducing bacteria in different treatment groups were diverse. Additionally, the iron(Ⅲ) reduction process was accompanied by the generation of reactive oxygen species (ROS). The content of hydrogen peroxide (H₂O₂) was the highest, ranging from 0.32 to 0.73mmol/L, and be show a significant positive correlation with the contents of ionic Fe²⁺, surface-adsorbed Fe(Ⅱ), and high-crystalline iron, while exhibiting a significant negative correlation with the content of iron in organic complex state. Hydroxyl radical (^•OH) has a significant positive correlation with ionic Fe²⁺, adsorbed Fe(Ⅱ), and high-crystalline iron. Superoxide anion (O₂^•−)has a significant positive correlation with low-crystalline iron and a significant negative correlation with adsorbed Fe(Ⅱ) and high-crystalline iron. The research results provide a new perspective for understanding the role of earthworms gut microbiota in soil iron cycling and ROS formation, which can be applied for pollutant control and degradation.

The weathered soil profiles were taken as the research objects from paddy and upland fields, which are typical agricultural lands in the carbonate rock regions of South China. The sources of soil heavy metals were traced via Pb isotope composition, and the vertical distribution and influencing factors of eight common types of heavy metals in the farmland soil profiles were systematically analyzed. The results revealed that the weathering of parent rocks was the main source of soil heavy metals in the study area, and the contents of heavy metals in the two profiles were found to be higher than the soil background value (0.056mg/kg). The enrichment of Cd tended to occur in the surface layer (0.49~2.15mg/kg) and the middle layer(0.75~1.87mg/kg) of the soil profiles, while that of the other elements tended to occur in the middle layer. The physicochemical properties and the mineral compositions of the soils, as well as the changes in the redox conditions exerted important impacts on the migration of heavy metals. The secondary enrichment of heavy metals in the soil profiles from the study area was attributed to the weathering process of carbonate rocks, while the impact of the leaching process on the migration and enrichment of heavy metals was more significant in the profile from the paddy field.

The Net Anthropogenic Nitrogen Input (NANI) model was utilized to estimate nitrogen inputs to Quzhou for the period from 2003 to 2022, and its spatial and temporal patterns, variations in components, and determining factors were examined. The results indicated that the average NANI for Quzhou over the past two decades was 12925kg/(km²·a), with a peak of 15698kg/(km²·a)in 2011. The spatial distribution was found to demonstrate an east-high and west-low pattern, which was consistent with land-use configurations. The predominant component of NANI was nitrogen fertilizer, which contributed 27% to 41%, followed by net nitrogen input from food/feed at 22% to 42%, atmospheric nitrogen deposition at 21% to 33%, and nitrogen fixation at 7% to 11%. The variations in NANI were primarily driven by nitrogen fertilizer application between 2003 and 2008, food/feed inputs between 2009 and 2014, and atmospheric deposition in recent years. Strategies were proposed to mitigate NANI, including promoting new energy vehicles, reducing nitrogen fertilizer application to align with standards of agriculturally advanced nations, and regulating livestock and poultry farming to match local demand. It was anticipated that these measures would decrease NANI by approximately 833, 893, and 896kg/(km²·a), respectively, achieving a cumulative reduction of about 2622kg/(km²·a), positioning it among the lower levels globally.

With the gradual depletion of shallow coal resources in mines and the continuous advancement of structural reforms on the supply side of national energy, the number of abandoned mines has increased, drawing growing attention to the environmental issues left behind in these areas. This study focuses on the abandoned mine in the Wansheng Economic Development Zone, Chongqing City. We collected five types of samples, including water (n=7), sediments (n=4), soil (n=8), coal gangue (n=2), and plants (n=10). The concentrations of the 16priority polycyclic aromatic hydrocarbons (PAHs) identified by the United States Environmental Protection Agency (USEPA) were analyzed using gas chromatography-mass spectrometry (GC-MS). Positive matrix factorization (PMF) and Monte Carlo simulation were employed to analyze the sources of PAH pollution and the carcinogenic risks in various environmental media within the abandoned mine. The results showed that the concentrations of PAHs in river, leachate, sediments, surface soil, coal gangue, and dominant plants were (45.6±12.4), (97.8±89.4)ng/L, (3640±2520), (6400±2650), (18600±1120), and (801±1110)ng/g, respectively. In the river, leachate, coal gangue, and dominant plants, the 2-3 ring PAHs are dominant, accounting for 83%,71%, 39%, and 54%, respectively. In the sediment and surface soil, the 5-6 ring PAHs have a relatively high proportion, accounting for 37% in both. The PMF source apportionment results indicated that diagenetic sources and petroleum source (49%) and traffic sources (32%) were the main contributors to PAHs in water. Traffic sources (48%) and coal combustion sources (35%) were the primary sources of PAHs in surface soil, while traffic sources (46%) and petroleum source and coal combustion sources (38%) were the major sources of PAHs in dominant plants. Monte Carlo simulations revealed potential carcinogenic risks to local residents from soil, coal gangue, and self-cultivated vegetables in the abandoned mine, with adults facing higher health risks than children. Over 96% of the carcinogenic risks were attributed to dermal contact.

An Approximate Homogeneous Turbulence Simulation system was employed to systematically explore algal responses to the interactive effects of turbulence and salinity by integrating the regulatory roles of these interactions on photosynthesis, nutrient metabolism, extracellular polymeric substances secretion, and grazing activities. It was demonstrated that at the biomass level, the damage to algae caused by turbulence was enhanced at 1‰ salinity, with Chl-a content in the low- and high-turbulence groups being 0.37 and 1.41 times that of the still-water group, respectively. At 4‰ salinity, damage was mitigated, with Chl-a content in these groups being 0.82 and 2.29 times that of the still-water group. This phenomenon was attributed to the regulation of algal photosynthetic efficiency and nutrient utilization rate by salinity. At the community structure level, the energy metabolism was enhanced by the increased salinity, which resulted in a lower water pH, thereby providing a competitive advantage to diatoms and leading to their dominance within the phytoplankton community. However, gas exchange and the shift in zooplankton composition were intensified by the elevated turbulence, mitigating the competitive advantage of diatoms caused by increased salinity. Consequently, the proportion of cyanobacteria increases, reinstating them as the dominant phylum.

Taking Huaihai Economic Zone as an instance, the spatio-temporal evolution of land use were analyzed from 2003 to 2023. On this basis, the spatio-temporal heterogeneity and spatial agglomeration of landscape ecological risk were identified for different historical periods and scenarios by combining PLUS model, spatial statistical method and ecological risk assessment model. The results indicate the following: (1) The land use types in Huaihai Economic Zone were mainly cultivated land and construction land. The overall land use pattern has not changed much in the past 20years. Concretely, it mainly manifested as the transformation of cultivated land into construction land. (2) The landscape ecological risk index (LERI) firstly increased and then decreased. In addition, the index was high in the east but low in the west of the study area. Furthermore it was relatively high in the north but low in the south. (3) The Moran's I index of the LERI decreased first and then increased. However, the local spatial agglomeration were mainly 'high-high' and 'low-low' patterns. (4) The LERI under the three scenarios of natural development, economic priority and ecological protection were 0.2470, 0.2451 and 0.2489, respectively. Under the ecological protection scenario, high ecological risk area accounts for the largest proportion across the whole regions. In contrary, the area of low ecological risk area accounts for the largest proportion in the scenario of economic development.

In order to explore the effect of biodegradable polylactic acid microplastics (PLA-MPs) on nitrogen conversion in sediments, a laboratory experimental sediment system was constructed, and 0 (control), 0.05%, 0.5% and 5% (W/W) PLA-MPs were added to freshwater sediments, then the incubation experiment was performed for 45d at 25℃ and light intensity of 40µE/(m²·s). The concentration of dissolved organic carbon (DOC) decreased significantly and the concentration of dissolved organic carbon (DOC)increased significantly (P<0.05), and the formation of CO₂ and CH₄ was promoted. At the end of the experiment, the concentration of NH₄⁺-N was reduced by the addition of PLA-MPs, and the concentrations of NO₃^--N and TN in the 0.05% and 0.5% PLA-MPs treatment group were lower than those in the control group (compared with the control group, the TN concentrations of the overlying water decreased by 68.44% and 61.83%, respectively). On the contrary, the TN accumulation in the 5% PLA-MPs treatment group was recorded (the TN concentration in the overlying water was 5.71mg/L at the end of the experiment) and was significantly higher than that in the control group (P<0.05). The NO₂^--N concentration in the 0.5% and 5% PLA-MPs treatment groups decreased and the release of N₂O was reduced, while the concentration of NO₂^--N in the 0.05% and 5% PLA-MPs treatment groups was increased. The addition of PLA-MPs promoted the expression of nitrogen-fixing genes nifH and nitrification genes amoA, and the denitrification genes nirS and nosZ were enriched in the 0.05% and 0.5% PLA-MPs treatment groups. However, the abundance of denitrification gene narG was only up-regulated in the 0.5% PLA-MPs treatment group. The abundance of narG and nirS genes in the 5%PLA-MPs treatment group was down-regulated, and the expression of nosZ gene was inhibited but then promoted. The results show that PLA-MPs changes the properties of the overlying water and sediment, promotes nitrogen fixation and nitrification, and provide carbon source to enhance denitrification and denitrification under 0.05% and 0.5% PLA-MPs treatments, but the reduction of NO₃^--N and NO₂^--N is inhibited due to low pH in 5% PLA-MPs treatment, resulting in TN accumulation.