The blending of MSW with aged waste could realize the resource utilization of both at the same time. Thermogravimetric analysis was used to study the combustion process of MSW blended with aged wastes. The combustion characteristics parameters of samples with 100%, 75%, 50%, 25% and 0 blending ratios of aged waste were calculated based on the thermal characteristic curves obtained. Further, the Kissinger-Akahira-Sunose method (KAS method) and Coats-Redfern integral method (C-R method) were applied to investigate the kinetic properties of the blending, and the fitting effectiveness and adaptability of the computational model were evaluated based on the fitting correction factor (adjR2). The results showed that the ignition characteristic index of the samples decreased when the mixing ratio of aged waste increased, while the burnout characteristic index and the integrated combustion characteristic index both showed a tendency of first increased and then decreased. Under the experimental conditions, the dominant mixing ratios of the burnout characteristic index and the integrated combustion characteristic index were 0~50%, and the integrated combustion characteristic index reached the peak at the mixing ratio of 25%. With the increase of the blending ratio of aged waste, the global activation energy calculated by the KAS method showed a decreasing trend from 244.49 kJ/mol to 79.40 kJ/mol, and its adjR2　increased from 0.936 6 to 0.988 9; and the global activation energy calculated by the C-R method showed an increasing trend from 20.86 kJ/mol to 34.21 kJ/mol, while its adjR2 increased from 0.985 0 to 0.997 5. Comparing the fitting curves of the two kinetic models with the experimental data, it could be seen that the fitting curve of the KAS method had some distortion in the high temperature combustion section, and the fitting effect of the C-R method was better in general.

A 600 t/d grate furnace of a municipal solid waste incineration power plant in southern China was taken as the research object, the operation optimization and control method of cooperative disposal of industrial organic solid waste in the solid waste incineration power plant were studied. By using the grate furnace of the solid waste incineration power plant, the mixing test of industrial organic solid waste was carried out. By changing the mixing ratio, the primary and secondary air volume, and the residence time of each grate section, the effect of mixing industrial organic solid waste on incinerator was studied. The results showed that the existing MSW incineration power plant could realize the collaborative disposal of industrial organic solid waste with less than 20% combustion content, and the incineration condition was better when the collaborative disposal volume was at a low level. In the actual operation process, the increase of primary and secondary air volume was helpful to improve the oxygen concentration in the furnace, so as to increase the evaporation of the incinerator. And the secondary air had more functions in increasing the first flue gas disturbance and reducing the coking of the furnace. The residence time of each grate should be adjusted according to the composition of the mixed waste.

The production of municipal solid waste (MSW) in the Tibet Autonomous Region increased from 1.73×105 t to 6.92×105 t from 2011 to 2021, with an average annual growth rate of 14.87%. With numerous glaciers and lakes in Tibet, the ecological environment is fragile and sensitive. At present, landfilling is the main method for waste disposal, which posed a risk of pollution to soil and groundwater. Based on the analysis of MSW production and regional distribution characteristics on the Tibetan Plateau, gasification was proposed to be a suitable treatment of MSW in Tibet. And the environmental benefits of waste gasification in Tibet were evaluated and analyzed. Air gasification experiment was carried out in a tubular furnace with 5 g model waste as raw material. The results showed that the optimal gasification conditions were reaction time as 20~30 min, air flow rate as 300 mL/min, moisture content of waste as 20%~30%, and vaporization temperature as 800~900 ℃. Under these conditions, the mass distribution of solid, liquid and gas phases were 8%~11%, 24%~28% and 60%~65%, respectively. The syngas yield could reach to 2.15 m3/kg, and the gas calorific value was 6.34 MJ/m3. The highest gasification efficiency could reach to 79.47%.

　A 400 t/d incineration project was taken as an example, the operation economic characteristics of wet deacidification of waste incineration under different technology systems were comprehensively analyzed. The results showed that for the project with low inlet pollutant concentration, the operating cost of the de-whitening condition was much higher than that of the non de-whitening condition. The electricity cost of the circulating pumps was the main operating cost of wet deacidification process, which was up to 77%. Reducing power consumption was the key to reduce operating cost. The outlet temperature of the wet tower had a significant impact on the operating cost. For every 1 ℃ decreased in outlet temperature, the operating cost increased by approximately 0.2-0.4 yuan per ton of waste. When the price of water was higher than 8 yuan per ton, the operation economy of the de-whitening condition would be better than that of the non de-whitening condition with the appropriate outlet temperature of the wet tower. With the increase of the concentration of inlet pollutants, the operating costs of wet deacidification increased linearly, and the cost of alkaline solution accounted for about 73% of the total costs. A combination of semi dry and wet processes could improve economic efficiency.

Due to the advantages in high efficiency of power generation and low emission of dioxin, power generation with domestic waste pyrolysis gas has become a solid energy equipment technology with great popularization value. However, the tail gas particulates that from internal combustion engine power generator for domestic waste pyrolysis gas caused the problems such as automatic shutdown, unstable power generation and substandard emission. The composition characteristics and influencing factors of tail gas particulates were analyzed in this study. The results showed that the white powder was mainly composed of SiO2, which was largely from the tar and siloxane in pyrolysis gas. In order to improve the power generation tail gas, so that it could steadily and continuously meet the emission standards, multistage tar capture device and high-temperature ceramic dust collector were supplemented in the power generation unit. The tar content in the gas was less than 50 mg/m3, and the dust content in the exhaust gas was less than 5 mg/m3, which met the index requirements of the DB 11/1056—2013 Emission Standard of Air Pollutants for Stationary Internal Combustion Engines.

With the rapid development of waste power generation industry, its energy utilization efficiency is the focus of attention, so that the ongrid amount of power generation has become the evaluation index of efficiency. Under the condition of stable waste disposal and calorific value, and stable power generation, how to seek measures to reduce power consumption and improve ongrid power in electrical equipment operation has become one of the goals pursued by waste incineration power plants. A representative waste incineration power plant was selected, through analyzing its actual operation data and equipment selection scheme, the function of electrical equipment in energy saving and consumption reduction was described in detail and relevant suggestions were put forward.

he secondary aerobic composting process and the prefabricated batch dynamic composting device were adopt, the collaborative dynamic composting experiment of garden waste and perishable waste was conducted on site in Xiaogang Village, Fengyang County, Anhui Province. The influence of water content on the collaborative composting effect under different raw material ratios was studied. Based on energy conservation, the minimum ventilation volume of single warehouse was 0.017 m3/min in the heating stage, and the maximum ventilation volume of single warehouse was 0.16 m3/min in the high temperature stage. The results of collaborative composting experiment showed that the higher the water content of raw materials, the better the temperature and reduction effect of primary composting. When the moisture content of raw material was 73.15%, the temperature could be reached to 65 ℃ after ten hours of feeding, and could be maintained above 65 ℃ for more than three days, which was better than the composting effect under traditional composting conditions with a moisture content of 45%-65%. The collaborative composting of garden waste and perishable waste with different moisture content could realize harmless products in the primary composting stage. After one month of secondary composting, the total nutrient and organic matter content of the compost product met the requirements of NY/T 525—2021 Organic Fertilizer, and the seed germination index could reach 50%, which basically met the requirements of local utilization.

In order to explore the effects of adding Ureibacillus suwonensis E11 on the performance of methane production during thermophilic (55 ℃) anaerobic digestion of food waste, and optimize the experimental conditions for bioaugmentation. A 5 L continuous stirring anaerobic reactor was used in this study with kitchen waste as substrate long-term acclimated high-temperature anaerobic sludge as inoculum. By changing the microbial addition amount (0, 5%, 10%, 15%, 20%), the methanogenic performance of high-temperature anaerobic digestion was compared, the enhancement effect was evaluated, the optimal addition dose was determined, and the mechanism of bioenhancement was revealed by combining metagenomic data. The results showed that compared to the control group without the addition of functional microorganisms, all bioaugmentation groups exhibited a significant increase in methane production. The optimal addition rate of functional microorganisms was 15%, and under this condition, the cumulative methane production (measured as VS) in the bioaugmentation group (575.14 mL/g) was 27.00% higher than that in the control group (452.86 mL/g). Bioaugmentation could improve the utilization efficiency of acetic acid to a certain extent. Analysis of the microbial community structure revealed that bioaugmentation promoted the methane production during thermophilic anaerobic digestion of food waste by increasing the relative abundance of several key hydrolytic bacteria and the hydrogenotrophic methanogen Methanoculleus.

　In order to provide basic data for the systematic evaluation of the environmental performance of the source separation of municipal solid waste and odor pollution control, the odor composition and emission characteristics shift of a food waste composting plant before and after the implementation of Beijing Municipal Solid Waste Management Regulation (hereinafter “Regulation”) were explored based on field investigation in this study. The results showed that, before and after the implementation of the “Regulation”, the relative composition and proportion of odorous pollutants in each sector of the food waste composting plant varied significantly. The emission of oxygenated compounds, protein-derived sulfur-containing compounds and terpenes (mainly limonene) derived from plants, fruit and vegetables increased. The mass proportion of above three kinds of odorous pollutants increased from 48.12%-72.20%, 0.25%-0.39% and 1.17%-3.16% before implementation of the “Regulation” to 64.22%-92.65%, 0.56%-43.54% and 2.35%-9.58%. Sulfur-containing compounds (methyl sulfide, dimethyl disulfide and dimethyl trisulfide) and terpenes became important odor contributing matter in addition to oxygenated compounds, and the odor contribution rates increased from 2.43%-17.20% and 0.36%-3.11% to 20.72%-45.69% and 4.11%-27.90%, respectively. Oxygenated compounds and terpenes were the main ozone pollution precursors (28.96%-88.28% and 7.53%-31.40% of ozone formation potential contribution rate). The oxygenated compounds were mainly alcohols (ethanol, n/isopropyl alcohol), ethyl acetate, 2-butanone and hexanal. Correspondingly, the mass proportion, odor impact and ozone pollution contribution of aromatic compounds, which derived from plastic bags, foam plastics, pesticides, and so on, decreased to 1.16%-12.13%, 0.65%-12.64% and 3.59%-57.70%, respectively. In particular, the emission of benzene reduced and it brought about the total carcinogenic toxicity of aromatic compounds decreased. The comprehensive results showed that the implementation of the “Regulation” had a significant effect on odor composition and its environmental and ecological impact of food waste composting plant.

The hydrolytic acidification liquid of kitchen waste contained rich volatile fatty acids (VFA), lactic acid and other degradable organic substances, which had good biodegradability. It could not only produce biogas through anaerobic digestion, but also be used as a substitute for traditional sewage treatment systems external carbon sources, with a wide industrial application market. Therefore, the hydrolysis acidification treatment technology of kitchen waste is the key condition for its efficient resource utilization, and the effect of hydrolysis acidification would directly affect the subsequent resource utilization rate. A large-scale kitchen waste treatment project in Zhejiang province was taken as an experimental platform, the treatment effects of bio-hydrolysis reactor under two processes of leaching and no leaching and no filtration were compared, and the main factors affected the effect of bio-reactor, such as residence time and reaction temperature were explored. The experimental results showed that compared to the leaching process, the no leaching and no filtration process could increase the reactor reduction rate by 4.17%, increase the key indicators of COD in the hydrolysate by 7.49%, and increase volatile fatty acids(VFA) by 19.30%. Moreover, the no leaching and no filtration process could optimize the reactor design and reduce its construction and operation costs. Under the no leaching and no filtration process, with a residence time of two days and a reaction temperature of 35 ℃, the extruded effluent had a pH of 4.87, COD of 129 200 mg/L, VFA of 23 691 mg/L, TN of 3 128 mg/L, and NH3-N of 1 011 mg/L.

Based on the actual case of a medium temperature dry anaerobic fermentation system for kitchen waste in Chongqing， the changes of solid content, alkalinity, volatile fatty acids, ammonia nitrogen, pH and methane concentration in the debugging stage were studied. The operation results showed that methane content could reach more than 55% in about two weeks after starting anaerobic fermentation with biogas residue and cow manure. The system could run stably when the pH was maintained between 8.0-8.2, the alkalinity was between 12 000-14 000 mg/L, the volatile fatty acids was between 2 500-3 000 mg/L, and the ammonia nitrogen was about 2 500 mg/L. With the material moved to the back end of the fermenter, the solid content and volatile fatty acids gradually decreased, the total alkalinity and pH gradually increased, and the ammonia nitrogen had no obvious change trend. After stable operation of the system, the gas production per unit feed volume of the anaerobic fermenter was about 140 m3/t, and the methane content was maintained between 55%-65%. The three-stage dewatering system operated stably and had good dewatering effect.

Based on the data of medical waste production and disposal during the COVID-19 in Henan province from January 2020 to December 2022. The characteristics of medical waste production sources, main components, production quantity, as well as disposal capacity and disposal facilities during the epidemic were analyzed. And the suggestions were put forward to solve the prominent problems of medical waste emergency disposal. The results showed that 46.60% of the medical waste was domestic waste generated from patients and isolation observation personnel in 2022; Centralized disposal facilities were the main means of medical waste disposal. Municipal solid waste incineration facilities played a crucial role in the emergency disposal process of medical waste.

Municipal solid waste incineration (MSWI) fly ash is a particulate matter collected by the air pollution control system, containing pollutants such as heavy metals and dioxins, which was listed in the National Hazardous Waste List (2021 edition). Water washing was required to remove chlorine and other soluble salts before the fly ash was melted or treated in a cement kiln. A small-scale test of water washing was carried out on waste incineration fly ash. The solution after washing was obtained and its composition was detected. According to the test results, the soluble salt content in fly ash and the washing loss rate of fly ash after washing were calculated. The experimental results showed that the soluble salt content in fly ash was 54.6%, and the main component was chlorine salt. The chloride ion content was the highest in the solution, which was about 40 g/L. Washing could remove most of the chlorine salts in fly ash, but the removal of heavy metals was poor. Under the condition of liquid-solid ratio of 6.5∶1.0 （mL/g）, the washing loss rate of fly ash water reached more than 40%. The results of the washing loss rate calculated by the mass loss of dry based fly ash before and after washing and the composition of solution after water washing were consistent, which proved that the method of estimating the wash loss rate of fly ash by the composition of water wash solution was feasible in engineering practice.

In-situ backfilling after excavation of old waste soil is of great significance for landfill resource utilization. The typical old waste soil was taken as the research object, the test of curing mechanical properties of humus soil in landfill was carried out, and the effects of different curing reagents of ordinary portland cement, sulphoaluminate cement, blast slag and cement blends on curing mechanical properties were compared and analyzed. The results showed that the mechanical properties of humic soil were improved obviously after curing agent treatment, and the performance of sulphoaluminate cement was better than that of other curing agent. After solidification, the strength of mixed particle size waste could still meet the requirements of mainstream road subgrade soil standards in our country.

The nanofiltration(NF) and reverse osmosis(RO) concentrated landfill leachate was pretreated by electrolytic process. The COD removal effect of nanofiltration concentrate under different electrolytic conditions was investigated and the optimal parameters of electrolytic pretreatment were determined. The AO-MBR process was adopted, the salinity acclimated sludge with tolerance of 30 mg/L NaCl was incubated as seed sludge, the electrolytic treated NF and RO concentrated liquid mixture was used as the treatment object, and the removal efficiencies of COD, ammonia and total nitrogen were investigated. The result indicated that under the optimum electrolysis conditions of treatment time of 2 hours, current density of 10 mA/cm2, and inter-electrode distance of 1 cm, the removal efficiency of COD and salinity were 65%-75% and 24%, respectively. When the mixing ratio of electrolytic treated NF and RO concentrate in influent was less than 1∶1, the removal efficiencies of ammonia and total nitrogen were above 92% and 86%, respectively. But those efficiencies decreased to 50% and 60% when the mixing ratio was above 2∶1. It was found that the mixing ratios of electrolysis of NF and RO concentrate in influent did not affect the removal efficiency of COD significantly.

Road dust and fugitive dust are important sources of particulate matter in urban ambient air. In order to promote the construction of Chengdu park city, the relationship between different cleaning methods and road dust and fugitive dust was explored through simulation experiments. The results showed that when the dust load and dust volume were high, the single operation method of “dry sweeping” had the highest removal efficiency for both the dust load (86.78%) and dust volume (66.95%), but the sensory experience of the crowd was poor. The effect of “washing and sweeping” was inferior to “dry sweeping”, but the sensory experience of the crowd was better. Priority should be given to selecting the combination method of “dry sweeping+washing” and “washing sweeping+washing”. When the dust load and amount were low, a single operation method of “dry sweeping” or “washing sweeping” was sufficient. During the road cleaning operation, the mass concentrations of TSP, PM2.5 and PM10 in the roadside atmosphere increased by about 20%; After 5-10 minutes of cleaning, the concentration of particulate matter in the roadside atmosphere would not be affected. It was suggested that the road cleaning vehicles could be improved by adding partitions or dust collection covers and other devices to promote the “dry cleaning” with high cleaning efficiency. New materials or new technologies such as dust suppressor and ablation agent could be introduced to remove the old and compacted residual soil embedded in the road structure on both sides of the road, that could effectively improve the sensory comfort of the crowd and protect human health.

With the continuous promotion of large-scale housing construction and underground space engineering, the construction waste had increased significantly and become the largest category of solid waste production. If not effectively controlled and properly disposed, it would cause enormous pressure on the environment, thus making the city face the dilemma of besieging by construction waste. Therefore, source reduction and comprehensive utilization were the best way to control urban construction waste in the future. Taking Shenzhen as an example, the study explored the implementable strategies of reduction and comprehensive utilization of construction waste from the entire process of planning， design，construction， and resource utilization based on current situation analysis and advanced experience at home and abroad, in order to achieve urban green urban development and the construction of a zero waste city. It was expected to provide countermeasures and suggestions for reduction and comprehensive utilization of the construction waste in megacities with high intensity and high quality development.