Evaporation is much higher than rainfall in arid loess area， evaporation reduction by irrigating soil cover was a feasible way to treat landfill leachate in situ in this area. In order to find out the influencing factors of evaporation reduction， the correlation between evaporation of loess irrigated by leachate and meteorological conditions， irrigation intensity （soil moisture content after irrigation） and leachate water quality were studied by simulating the cover layer in a landfill in Lanzhou. The results showed that the local water surface evaporation（E1） was mainly related to temperature（T）， pressure（P）， air humidity（HUM）， wind speed（W）， precipitation（R） and sunshine duration（S）. The fitting equation was E1=12.529+0.256T-0.010P-0.062HUM+0.351W-0.007R+0.022S. There was a linear relationship between the water surface evaporation of pure water and leachate. Under different soil water content of 25%， 20% and 15%， the evaporation of leachate irrigation decreased with the decrease of water content， and the evaporation at 25% water content was the maximum under non-liquefaction conditions. According to the meteorological data of the test site， the annual water surface evaporation was 1 405.82 mm， and the leachate irrigation evaporation was 806.09 mm. The annual evaporation loss of leachate per unit area of loess overburden was about 0.8 m3m2.The efficient treatment of toilet black water and yellow water was an essential component of current wastewater treatment. According to the research process and treatment mode， the black water treatment technology could be divided into centralized black water treatment technology， dispersed black water treatment technology， emerging black water treatment technology and black water resource technologies. Most technologies， including biological， physicochemical， and other treatment methods， were focused on the treatment and recovery of nutrients due to the high concentration of nitrogen and phosphorus resources in source-separated yellow water. The different technical characteristics， principles， research status and application cases of black water and yellow water were summarized. And the corresponding development directions， such as source separation technology development， micro-pollutants advanced treatment and high-quality resource recovery were proposed.

The in-situ treatment scheme of a residue landfill in Qingshuitang Industrial Zone， Zhuzhou City was discussed. The properties of the waste residue and site conditions were considered， and the scheme of “vertical barriers+in-situ stabilization/solidification+leachate collection and treatment+site closure” was proposed. After the industry residue treatment， the heavy metals such as Pb， Cd and As could be effectively immobilization. The preliminary calculation of the emission reduction of Pb， Cd， As was 2 598.48 t， 7.31 t， 1 091.36 t， respectively. The double-row vertical barriers with a permeability coefficient of 1×10-7 cm/s and a compressive strength of 2.0 MPa （28 d） could meet the penetration distance up to 30 years （0.95 m）. The analysis results of the samples from the groundwater monitoring wells surrounding the slag landfill showed that the water quality met the requirements of class III of the GB/T 14848—2017 Standard for Groundwater Quality. The study could provide reference for the design of other similar cases in China.

Landfill is a traditional way to treat domestic waste in China. It had not only occupied large-scale land and space resources， but also posed long-term potential risks to the surrounding air， soil， groundwater， and residents’ living environment， which has been repeatedly notified by environmental protection inspectors. With the promotion of full coverage of incineration treatment， the renovation and utilization of existing waste landfills has gradually become a new task in many areas. First， the demand and practical exploration of landfill renovation and utilization were sorted out. Then the process， technical requirements， and application scope of the two main technical routes of ecological restoration and mining reuse were analyzed. Finally， three business models of EPC（engineering procurement construction）， ROT（retrofit-operate-transfer） and EOD（ecology-oriented development） were proposed for the implementation of the project， and suggestions for their application were given. For projects using ecological restoration technology， the boundary conditions was generally clear and the business was non-profit， so the funds should be implemented from the local government financial budget， and the EPC mode could be adopted. For projects with public welfare development after waste mining， if the local government financial fund was sufficient， the EPC mode could be adopted， if the local government financial fund was insufficient， the ROT mode could be adopted to introduce private capital for cooperation. And the EOD mode was more suitable for the projects of business development after waste mining.

The treatment project of leachate membrane concentrate in a domestic waste landfill in Jiangxi Province was taken as a case， the technical advantages and application prospects of pretreatment + MVR forced cycle evaporation crystallization + mother liquid drying were expounded. The practical engineering showed that the technology could effectively reduce hardness， CODCr and other indexes. Moreover， inorganic miscellaneous salts such as Na+， K+ and Cl- could be formed into crystals and extracted from the system. The treated effluent water quality stably meet the requirements of the emission limits of table 2 in the GB 16889—2008 Standard for Pollution Control on the Landfill Site of Municipal Solid Waste. The moisture content of the mother liquid was reduced by 75.9 percentage points after drying treatment， achieved the purpose of reducing the waste quantity to reduce the cost of external transportation. After more than one year of formal operation， the performance indicators of this case were good， and the technology could be applied to the treatment of membrane concentrate.

High temperature corrosion is one of the key factors restricting the long-term stable operation of waste incineration power plants. A waste heat boiler of a waste incineration power plant was taken as the research object， the gas temperature， steam temperature， tube wall temperature of superheater and the distribution of velocity filed in furnace before and after modification were analyzed. The results showed that the high temperature corrosion risk of the superheater could be reduced by strictly controlling the tube wall temperature of superheater through optimizing the layout of heating surface and designing the furnace arch， and improving the non-uniformity of flow field scouring in the horizontal gas pass. At the same time， the corrosion resistance of 12Cr1MoVG material was decreased evidently when the wall temperature was higher than 472 ℃， while TP347H material still had good corrosion resistance when the wall temperature was about 493 ℃ and below. It was recommended that when the wall temperature was higher than 465 ℃， stainless steel with corrosion resistance no less than TP347H or other anti-corrosive processes could be used for tube wall.

Using the existed municipal solid waste（MSW） incineration plants to co-incinerate with industrial solid waste（ISW） could not only effectively utilize the capacity of MSW incineration plants， but also co-dispose with ISW. The co-incineration ratio of ISW in the existed MSW incineration plants， the low heat value （LHV） of the mixture， and the limitation and influencing factors were analyzed， which proved that it was feasible for the existed MSW incineration plant to co-incinerate with a certain ratio of ISW. Four waste pit management schemes were provided, when ISW was co-incinerated in MSW incineration plants， and were analyzed and demonstrated， and the optimal scheme was recommended to provide reference for design， construction and operation of the related co-incineration projects.

A comprehensive technical analysis of SNCR and SCR process was carried out and corresponding economic model was set to analyze operation cost of different DeNOx processes for a 500 t/d plant. The results showed that SNCR was much more cost effective than SCR. The cost of reductant generally accounted for about 70% of the total cost of SNCR， and the cost of heat loss caused by reductant solution evaporation in the furnace could not be ignored. The economic difference of reductants should be reasonably analyzed with help of the isocost line. The operation cost of SCR was four to five times that of SNCR， the flue gas heating cost counted over half of the total cost while the direct cost of reducing agent was only 6%. The electrical consumption of urea pyrolysis process was over twice than that of ammonia process， thus ammonia solution was more cost effective than urea.

Irradiation technology has been widely used in industry， agriculture， medicine， environmental protection and other fields， which has great application potential in medical waste disinfection. The source， category， output and harm of medical waste in China were introduced， and the principle， advantages and disadvantages and operation cost of existing medical waste treatment technology were briefly discussed. On the basis of expounding the disinfection principle and application status of irradiation technology， the process flow， design parameters， investment and operation cost and commissioning effect of a medical waste treatment project by irradiation disinfection were introduced in detail. The operation results showed that compared with the existing disinfection technologies， the irradiation disinfection technology has the advantages of thorough disinfection， high treatment efficiency， no harmful substance residue， simple operation and low operation cost.

A combination of water washing pretreatment and thermal treatment may become a strategy for safe disposal and resource utilization of the MSW incineration fly ash. However， the influence of water washing on the migration and transformation of heavy metals has not been clearly studied， and the leaching risk of fly ash after disposal was underestimated by common leaching methods due to the strong buffering performance of fly ash. In view of the above problems， the curing mechanism of Pb， Zn and Cu in fly ash was studied， the influence of water pretreatment on the curing behavior of heavy metals was discussed. And a long-term leaching device with constant pH was designed to evaluate the long-term leaching behavior of fly ash after disposal. The results showed that the major product phases of Pb， Zn， Cu after the washing-thermal treatment were identified as lead-aluminosilicate， lead-calcium oxide， zinc silicate， zinc-aluminosilicate， etc. Meanwhile， the aforementioned phases were also detected in the scheme of only thermal treatment but with additional lead oxide chloride， lead aluminum oxide， lead silicate， zinc chloride and calcium copper oxide， etc. The types of Pb， Zn and Cu phases in fly ash after washing-thermal treatment were less affected by the sintering temperature and metal content. A higher Pb stabilization efficiency was obtained after washing-thermal treatment compared with only thermal treatmeat， with the value ranged from 94.59% to 99.60%. In the long-term leaching experiments with constant pH， the corresponding leachate pH of the two solutions were maintained in the range of 2.91~3.63 and 4.91~5.36. Leaching concentrations of Pb， Zn， Cu concentrations basically reached the maximum value after 600 mins， then decreased and maintained a low concentration at 0~0.09， 0.01~0.92， 0.03~0.22 mg/L（washing-thermal） and 0.03~0.31， 0.07~0.94， 0~0.11 mg/L （only thermal） respectively. The long-term leaching method proposed in this study could evaluate the long-term leaching risk of fly ash under extreme conditions， reveal the migration and transformation mechanism of heavy metals during the washing-thermal treatment process， and provide a reference for the safe disposal and resource utilization of fly ash.

The COVID-19 epidemic has led to a surge of the amount of medical waste， and the generation amount of medical waste in severely affected areas far exceeded their existing disposal capacity. Disposal of medical waste become a key link to prevent epidemic spreading. The characteristics， environmental risks and technical adaptability of two medical waste emergency co-disposal technologies including co-incineration with hazardous waste and domestic waste respectively were compared. The environmental impacts and key factors of the two technologies were evaluated and compared via life cycle assessment. The results showed that co-incineration with domestic waste has significant environmental benefits due to power generation. While co-incineration with hazardous waste could effectively avoid the secondary synthesis of dioxins， but had a great impact on the environment due to high energy consumption. Scenario analysis of co-incineration with hazardous waste showed that the energy recovery efficiency increased by 63.6%， energy conservation and emission reduction targets reduced by 21.9%. The results of the study could provide recommendations for the emergency management and sustainable development of medical waste.

According to the component characteristics of fly ash produced by a MSW incineration power plant， the effects of different compatibility ratios of single component and two components on the melting temperature of fly ash were analyzed. The results indicated that the addition of SiO2 could significantly reduce the melting temperature of fly ash， especially for every 1% step increased when the adding mass fraction was 0～5%， the reduction of ash melting temperature was about 14～21 ℃. The addition ratio of Al2O3 could decrease the ash melting point of fly ash within 10% ， but it could increase the melting characteristic temperature of the fly ash when the proportion was 10%～25%. Both CaO and MgO could increase the melting characteristic temperature of fly ash， and CaO could have a great effect. Coal ash with high content of acid oxides could obviously promote the melting of fly ash. Under the condition of alkalinity balance， the addition of binary components SiO2-MgO and SiO2-CaO would further reduce the melting temperature， and the melting aid effect of SiO2-MgO was more obvious than SiO2-CaO. On the contrary， the addition of binary components Al2O3-MgO and Al2O3-CaO would significantly increase the melting temperature of fly ash.

After the “four classifications” of MSW in Shanghai， the resource utilization of recyclable materials of glass， metal， plastic， paper and textile waste was a nationwide shortcoming in China’s domestic waste classification work. The quality and flow characteristics， recycling system status， recycling ways， related management policies and mechanisms of the recyclable materials in Shanghai domestic waste were analyzed through on-site investigation， videoconferencing， questionnaire survey， consultation and interviews. The main existed problems were discussed and suggestions for improvement were proposed. The results showed that the source classification of domestic waste in Shanghai had achieved remarkable results. The average daily collection amount of recyclable wastes was 7 000 t/d， mainly consisting of paper， metal and plastic waste. By the end of 2020， 1.5×104 recyclable recycling service points， two hundred and one transfer stations， ten distribution centers and sixty-four main recycling enterprises had been established. However， the scale of resource utilization of recyclables and efficiency were still low. Against the higher requirements of domestic waste management， the utilization of domestic recyclables needs to be improved in areas of laws and regulations， technical standards， classification methods， market cultivation， regional coordination， data statistics， inter-provincial supervision. On this basis， suggestions were given for designing a collaborative management mechanism.

By introducing four explanatory variables of environmental knowledge， public propaganda， economic incentives and contextual factors， the structural equation model based on the extended planning behavior theory was constructed. The key factors of Chengdu residents’ willingness to MSW classification were identified. Meanwhile， the effect of public propaganda on residents’ environmental attitudes， perceived behavior barriers， environmental knowledge and willingness to classify were discussed. The results showed that environmental attitudes， perceived behavior obstacles， environmental knowledge and situational factors had significant influence on residents’ behavior willingness of MSW classification. Public propaganda had no direct affect on residents’ willingness of classification， but it could indirectly affect residents’ willingness of waste classification through influencing environmental attitudes， perceived behavior barriers and environmental knowledge. Based on the above conclusions， in order to further facilitate the classification of MSW in Chengdu， the government should strengthen the propaganda for the knowledge and value of waste classification in the early stage of implementing waste classification， and at the same time， complete the supporting facilities for the classification and recycling of MSW.

Based on the practical needs of comprehensively establishment of the charge system of municipal solid waste （MSW） treatment in China， basic research such as the investigation of residents’ willingness to pay （WTP） in Shanghai was carried out. The results showed that waste treatment charges were mostly paid as you throw in foreign countries， while it was dominated by flat rate charging or water consumption coefficient in China. More than 60% of the respondents in this study paid close attention to the waste classification work， and thought that the residents’ dumping of waste played important role. In addition， the respondents’ WTP for the MSW treatment was 18.2 RMB per month per household， which was positively correlated with income and domiciliary register， and negatively correlated with age. Combined with the feasibility of current charging theory， policy and operation， relevant countermeasures and suggestions for establishing residents’ MSW charges in Shanghai were proposed. It may be difficult to achieve a satisfied effect of MSW source reduction only by adopting the flat rate charging. While the water consumption coefficient method was easy to implement， which could ensure a higher charge rate and lower charge cost， thus had certain operability. The implementation of pay as throw not only required investment in upgrading supporting equipment， but also may bring negative effects to the development of waste classification. The research results could provide basic data and decision-making reference to formally establishing residents’ MSW charges in Shanghai， which could conducive to further improve the whole process classification system of MSW.

The existence of marine garbage has seriously affected the ecological environment quality of offshore areas in China. The environmental protection of offshore areas is an essential part of the construction of ecological civilization in our country. According to the relevant documents and policies of garbage management of the offshore areas recently issued by China， and combining with the actual situation of marine garbage in the Chinese offshore area， the marine sanitation system was constructed from the technical point of view. The service technology routes of the whole process of marine sanitation， the overall operation mode of marine sanitation and the framework and functions of the intelligent management and control platform were discussed. The necessity of the sea and land coordination during the constructing， operation and maintenance of the marine sanitation system， the multi-department and multi-professional collaboration， establishing and improving the standardization of consultation and designing for the whole process of the marine sanitation system were put forward.