Taking Shaoxing municipal solid waste (MSW) and industrial solid waste (ISW) as the research objects, focused on the key and difficult problems of the large co-incineration proportion of ISW in MSW incineration system, the physical and chemical characteristics, the difference of combustion characteristics, the influence of the co-incineration ratio，and the influence of combustion on ash and slag characteristics of MSW and ISW were studied by combining the laboratory simulation and actual incineration system co-incineration test. It was found that the physical and chemical characteristics of MSW and ISW were significantly different, and ISW had more single composition, mainly textile waste (22.9%-72.0%), higher calorific value (9 121.2-14 975.8 kJ/kg) and volatile contents (44.9%-71.8%). And the pollution elements such as S and Cl introduced by ISW would bring certain challenges to the subsequent treatment of flue gas pollutants. The test results of combustion characteristics showed that the textile proportion of ISW was relatively large, resulted in higher ignition temperature, but a small temperature difference between the burnout temperature and the ignition temperature, that is, the combustion reaction after ignition was rapid and the time was short. The results of thermogravimetric (TG) analysis showed that the optimal co-incineration ratio of MSW and ISW was 1.00∶1.35, and the corresponding ignition temperature, combustion rate temperature and burnout temperature were lower than those of MSW, the flammability index C (2.73×10-5 %·min-1·℃-2) and combustion characteristic index S (4.34×10-8 %2·min-2·℃-3) also reached the highest level. In the operation process of MSW incinerator, a large co-incineration proportion of ISW (MSW∶ISW=1∶1) and increasing the ISW co-incineration ratio (MSW∶ISW=1.0∶1.5) would increase the slag thermal reduction rate, significantly expand the particle size of fly ash in the horizontal flue and bag, and reduce the characteristic melting temperature of fly ash. In addition, the increased contents of S/Cl also led to the increase of calcium absorbent dosage, resulting in more production of fly ash. The research results could provide a theoretical basis for the stable operation and technical optimization of the subsequent large-proportion co-disposal of ISW in MSW incineration system.

Incineration is the main treatment method for domestic waste, and a amount of greenhouse gases will be emitted during the incineration process. Taking a domestic waste incineration plant in Beijing as an example, greenhouse gas emission (GGE) accounting was carried out based on the entire process of domestic waste incineration. The results indicated that the CO2 equivalent intensity of GGE from domestic waste incineration was approximately 0.55 t/t. The domestic waste incineration had good potential for carbon reduction with 0.32 t/t of carbon storage capacity. From the perspective of production process, GGE from the treatment and utilization stages accounted for 99.00% of the total emissions. The contribution of CH4 and N2O was 10.81% in the processing stage. This study estimated that using domestic waste incineration to generate electricity was expected to reduce GGE by 99.842 1 million tons per year nationwide, with significant pollution and carbon reduction effects. This is of great significance for achieving the goal of carbon peak and carbon neutrality.

The SO2 removal technology based on activated carbon or coke could not only solve the pollution problem, but also realize the resource utilization of SO2 in flue gas. However, the exothermic reaction in the process of pollutants removal makes the temperature of activated carbon bed higher than that of flue gas, which is easy to cause accidents. Therefore, it is of great significance to study the oxidation reaction of activated carbon for the safe and reliable operation of the process. Spontaneous ignition temperature (SIT) and point of initial oxidation (PIO) were used to characterize the oxidation process of activated carbon sample. The oxidation reaction of different activated carbon samples was studied by thermogravimetric method in terms of powder sizes, heating rates, oxygen contents, raw material and metal oxides. The results showed that SIT and PIO values obtained by DSC profiles were higher than those obtained by TG profiles， on the whole. For practical operation, it was recommended to use the TG method to evaluate the oxidation reaction of activated carbon. The increase of heating rate would inhibit the oxidation of activated carbon, evidenced by ascending PIO and SIT values simultaneously, and the heating rate had a greater effect on SIT value. While the increase of oxygen content in gas could promote the oxidation, evidenced by descending of both PIO and SIT values with the increase of oxygen content, and the effect of oxygen content on PIO value was more obvious. Activated carbon derived from coal and coconut shell mixture had relatively good oxidation inhibition, and the metal oxides could facilitate the oxidation reaction between coal and coconut shell mixed activated carbon, among which vanadia showed the most significant effect, with PIO and SIT values dropped by 132 ℃ and 139 ℃, respectively.

The activation of persulfate by carbon-based catalyst has the characteristics of high efficiency, controllable and selective activation, and so on. However, most of the existing carbon-based materials (mainly carbon nanotubes, graphene and diamond) have harsh preparation conditions, complex processes, difficulty in large-scale production, high environmental application costs and performances need to be further improved. Biochar has attracted much attention in the field of environmental catalysis because of its simple preparation, low cost, adjustable specific surface area and large number of surface functional groups. N-doped bovine bone meal biochar (BBC-N0.005) was prepared by high temperature calcination using bovine bone meal and sodium ethanesulfate as raw materials. Bovine bone meal was made from fresh animal bone, which contained collagen, high carbon content, rich phosphorus content, and provided sufficient carbon source and natural doping element for improving catalytic performance. The physicochemical properties of BBC-N0.005 were analyzed by various characterization methods, and it was used to activate peroxymonosulfate (PMS) to degrade phenol. Meanwhile, the effects of different factors on the degradation of phenol and its degradation mechanism were investigated. The results showed that when N-doping mass ratio was only 0.005, BBC-N0.005/PMS could effectively remove phenol within 30 minutes. The degradation rate of the system could reach more than 80% in the pH range of 3 to 11, which had a good pH application range. The main active species in BBC-N0.005/PMS system were SO4?-,?OH and 1O2, and the pyridine nitrogen and graphite nitrogen on the surface of BBC-N0.005 were the main active sites for activating PMS.

With the development of the city, environmental protection requirements are increasingly strict, and the problem of sewer sludge outlet has gradually attracted the attention of the management department, and has also become a problem faced by the city. A number of sewage sludge treatment stations in China were investigated and their processes and existing problems were analyzed. On this basis, a sewage sludge treatment station in Wuhan was taken as an example, and combined with the characteristics of the project, the combined treatment process of “pretreatment + multistage separation + mechanical dehydration”, which has little influence on the downstream sewage treatment plant, was adopted. After treated, four types of residues were generated: bricks, stones, tree roots, plastics, etc., with a particle size greater than 100.0 mm; stones, plastics, scum, etc., with a particle size between 3.0 and 100.0 mm (not including 100.0 mm) and a moisture content of 11.4%; sand, organic matter, etc., with a particle size between 0.2 and 3.0 mm (not including 3.0 mm) and a moisture content of 21.8%; and silt with a particle size smaller than 0.2 mm and a moisture content of 25.7%. The unit operation cost in the station was 75.53 yuan/t according to the calculation of full load operation. At the same time, the problems existed since the operation were summarized in order to provide reference for the subsequent sewage sludge treatment projects.

Direct interspecies electron transfer (DIET) has a low dependence on diffusive mass transfer. In anaerobic digestion projects of urban organic solid waste with high solid content and ammonia nitrogen stress, DIET can serve as an additional methanogenic pathway. However, electroautotrophic methanogens that are known to participate in DIET lack conductive pili or outer membrane cytochromes, and extracellular electrons must cross the electrically inert cell membrane to enter the cell interior and participate in the CO? reduction process. Studies have shown that low-voltage electrical stimulation can improve the conductivity of membrane-bound proteins, but the effect is mainly concentrated in the biofilm enriched at the cathode, and continuous power supply will lead to excessive energy consumption, which is not conducive to large-scale engineering applications. In this study, granular activated carbon (GAC) was used as a packing material in the electrode coupled with intermittent power supply to investigate its impact on the anaerobic digestion performance of urban organic solid waste. The results showed that the GAC-packed electrode could extend the influence of the electric field from the cathode to its surface, increasing the methanogenic capacity by 26%. Cyclic voltammetry scanning was used in combination with the Randles-?ev?ík equation to calculate the electron transfer coefficient of the microbial film, and it was found that the microbial film on the GAC surface had more than double the electron transfer coefficient compared to the sludge in the reactor. During intermittent power supply, GAC could retain some of the electric field’s influence, and in the closed-circuit operation phase, the biofilm on the GAC surface had a stronger electrical signal response to scanning electrochemical microscopy and electrochemical Fourier transform infrared spectroscopy. Microbial community analysis revealed that adding GAC as a packing material in the electrode could enrich more methanogenic archaea related to DIET, for example, the relative abundance of Methanospirillum on activated carbon (39.86%) was much higher than that of the control group (21.45%). When the GAC was coupled with intermittent power supply, the relative abundance of Methanospirillum decreased from 39.86% to 25.84% during open-circuit operation.

　Taking the household food waste in five residential areas in different districts of Yangzhou(Guangling district, Hanjiang district and Jiangdu district) within one year as the objects, the concentration of heavy metals (As， Cd，Cu， Ni， Pb， Zn) in food waste was analyzed. Meanwhile, the applicability of food waste as composting raw material was researched and pollution risk assessment of heavy metals was carried out. The results showed that the concentration of Ni, Cd, Pb, As were relatively low, while the concentration of Cu and Zn were relatively high, with the maximum values of 6.35， 0.68， 2.81， 0.49， 26.1， 58.2 mg/kg, respectively. Through comparative analysis, the concentration of As, Pb and Cd in food waste were far lower than the limit of NY/T 525—2021 Organic Fertilizer, and the concentration of Pb, Cd, Ni, Cu, As were also much lower than the soil pollution risk screening value of the second type of land in GB 36600—2018 Soil Environmental Quality-Risk Control Standard for Soil Contamination of Development Land, which indicated that the food waste in Yangzhou would be suitable for composting raw material. According to the Hakanson potential ecological risk index method, the potential ecological risk index RI of heavy metals in food waste was calculated to be 0.45, indicating that the potential ecological risk caused by Cd, As, Pb, Cu and Ni of household food waste was low, and the organic fertilizer obtained by household food waste as compost raw materials would be safe to be applied to landscaping.

Dry anaerobic fermentation technology is one of the effective methods for treating kitchen waste, which can achieve waste reduction, resource utilization, and harmlessness, with low energy consumption and environmental impact. In the Chongqing Luoqi kitchen waste treatment project, the complete set of horizontal push flow single axis stirring dry anaerobic fermentation technology has been successfully applied through equipment introduction and technology development, achieving important technological progress. In the continuous operation in 2024, each unit operated stably and efficiently, with stable control of process parameters, and obtained a large amount of technical data. The daily average unit production of garbage biogas was 119.06 m3/t, with a volumetric gas production rate of 5.44 m3/m3, and the biogas components were stable at 55% to 65%. The production and solid content of dehydrated residue were effectively controlled, and the ratio of dehydrated residue to feed quantity was always controlled below 40%. The amount of biogas slurry was small, and the solid content of biogas slurry was stable below 1%. The key technical control indicators of dry anaerobic fermentation technology were obtained through data analysis, with an average feed volatile solid load（measured by VS) of 10.50 kg/（m3·d）.The average decomposition rate of volatile solids was 77.39%, and the average methane production（measured by VS) from volatile solids decomposed per unit was 472.58 L/kg. At present, the theoretical research on anaerobic treatment technology for high solid content waste materials in China is not yet complete, and most of the application projects cannot meet the production standards. Therefore, this study can provide theoretical and data basis for the research of dry anaerobic fermentation process in China, and also provide technical support for the promotion of dry anaerobic fermentation technology application in the field of kitchen waste in China.

Arsenic and antimony in soil have strong migration characteristics, their stabilization has always been a difficulty in the soil remediation industry. The stabilization effect experiment of arsenic and antimony was carried out in the arsenic and antimony contaminated soil at the former sites of seven arsenic plants in Hechi area, Guangxi. The effects of stabilizers on soil pH, arsenic and antimony leaching behavior and speciation in the soil were explored. The results showed that the soil pH remained in the range of 7.73 to 8.22 under the condition that the dosage of stabilized material was 10-70 g/kg. The stable efficiency of arsenic and antimony in soil was 65.4%-100.0% and 91.0%-99.7%, respectively. The largest proportion of arsenic and antimony in the soil was the residue state, which was more than 70.0%, and the smallest proportion was the non-obligate adsorption state(0-9.4%). The stabilization process of arsenic and antimony in soil is also a transformation process among non-obligate adsorption state, obligate adsorption state， and amorphous iron-aluminum oxide bound state. The results of this study can provide a reference for the stabilization and remediation of other similar high-concentration arsenic and antimony contaminated soils.

The sewage treatment station project of the second phase of domestic waste incineration power generation project in the central urban area of Dalian city was designed to partially reuse the effluent and partially discharge it. Among them, the water quality of the recycled part met supplementary water quality requirements of the open circulating cooling water system in the GB/T 19923—2005 Reuse of Urban Recycling Water-Water Quality Standard for Industrial Uses, and the discharge part should comply with the first level A standard of GB 18918—2002 Discharge Standard of Pollutants for Municipal Wastewater Treatment Plant. The main process of leachate treatment is “pretreatment + anaerobic + external MBR+ nanofiltration + reverse osmosis”, and the concentrated solution treatment adopts the process of “material film reduction+reinjection”. The overall operation of the project is good, and the effluent quality is stable and up-to-standard.

To address the increasingly severe challenges in landfill leachate treatment, particularly the surge in leachate during the rainy season, and to ensure the stable operation of the environmental park and ecological safety, Shenzhen Xiaping Environmental Park initiated a new leachate treatment capacity expansion and retrofitting project. This project was designed to process 1 200 m3/d of leachate, adopting a combined process of equalization tank + two-stage A/O-MBR(membrane bio-reactor)+ nanofiltration + reverse osmosis. The volume reduction + submerged combustion evaporation technology was utilized for concentrate treatment, achieving full quantitative treatment and significantly alleviating environmental pressure on the park. During implementation, challenges such as odor in evaporation tail gas and membrane equipment clogging (impacting treatment efficiency) were addressed through optimized process design and equipment configuration upgrades. A refined tail gas treatment process was combustion in evaporators + alkali scrubbing spray towers + temperature elevation + bag dust removal + botanical liquid spray，and process of coagulation sedimentation + filtration system was introduced before nanofiltration concentrate enters the volume reduction system to effectively remove macromolecular organics， ensure membrane system stability and mitigate odor issues. The successful execution of this project not only provides robust support for the sustainable development of waste disposal in the park， but also contributes valuable experience to the advancement of landfill leachate treatment technologies in China.

The in-situ aerobic stabilization technology is one of pre-treatment processes toward middle-low intensity development of landfills. The landfill-gas system and liquid system design as its core technology are still weak on basic theories research and engineering application experience, the engineering application summary is not yet systematic. Therefore, the process design and engineering application of landfill-gas and liquid system of in-situ aerobic stabilization technology were systematically investigated, especially focused on process design methods and application practice of engineering cases of well network distribution, aeration and pumping volume calculation in gas system and leachate collection, recharge and treatment systems in liquid system. Finally, the existing problems were pointed out and the future development direction was prospected.

Domestic waste landfills are gradually withdrawing from the stage of history, but the landfill waste stabilization cycle is long, in its degradation process will continue to produce leachate and landfill gas, which has a greater risk. In recent years, the excavation and screening resource utilization technology, which can completely eliminate the risk of waste storage and free up land resources, has been increasingly favored by the market. And the safety and environmental risks of landfill gas generated by excavation and sieving of garbage are the key problems faced by this technology. The rapid ventilation pretreatment technology proposing in this study can quickly reduce the landfill gas pollution load in the garbage pile, effectively guarantee the safe excavation of garbage and reduce the impact of odor, and the technology has the characteristics of rapid well construction, rapid installation and transfer, as well as good match with the excavation construction. Field tests were carried out to optimize the design of process operation parameters and verify the treatment effect of this technology. Result showed that after 7 days of rapid ventilation pretreatment, the methane concentration in the landfill body could be less than 2.5%, which could meet the limit requirements of GB 14554—1993 Emission Standards for Odor Pollutants.

The volume of small simple landfill is small. Based on site investigation, the project clearly adopted the main treatment technology of “excavation and screening + light material transport and incineration + humus soil backfilling” to clean up pollution and free up land resources. The screening scale and construction period in the process of waste excavation and screening mainly depend on the ability of the back-end incineration plant to receive the light combustibles on the screen. The storage space of the recyclables is based on their proportion and the frequency of clearing and transportation. The space of the drying site can store the excavated waste for 3 days. The size of the screening workshop is determined according to the screening scale. The waste excavation area was controlled within 1 000 m2, and the construction was carried out by step-by-step (layer) and relay excavation method. The moisture content of the waste after drying was reduced to 30%-40%, and the multi-stage high-efficiency waste comprehensive sorting equipment was used for sorting and classification. After the completion of site management, post-assessment and follow-up monitoring of the excavation area would be needed to ensure the final utilization of the site.

Based on the settlement experience model of Swoers and so on, a settlement calculation method of Chinese domestic waste landfills provided by Zhejiang University, combined with the characteristics of high-food-waste domestic waste, has been used to calculate the primary and secondary compression settlement, as well as the uneven settlement of vertical reconstruction of domestic waste landfills. The actual project settlements was monitored and compression settlement characteristics was analyzed. Additionally, the mechanical properties of different impermeable materials were collected to analyze their applicability in the engineering application of vertical reconstruction of domestic waste landfills. The results showed that the primary compression settlement had a short duration, while the secondary compression settlement lasted for 30 to 50 years. The compression settlement is nonlinearly proportional to the depth of the underlying domestic waste body and the height of the fly ash body, with the settlement rate decreasing as the depth and height increase. The landfilling slope ratio of the waste body is an important factor affecting uneven settlement, and it is recommended that the slope of the fly ash body be less than 1∶3 to ensure that the tensile strain of the impermeable lining is less than 10%. With the adoption of engineering measures such as bidirectional geogrids and buffer layers, combinations of materials such as HDPE membranes and geotextiles can be used as impermeable linings for vertical reconstruction, and the use of sodium bentonite waterproof blankets and clay in vertical reconstruction is not recommended.