Diesel, liquefied natural gas (LNG), pure electric and hydrogen-powered garbage transfer trucks were chosen as the research objects. The applicability of different trucks from different dimensions, such as vehicle endurance, total cost of ownership, carbon emission and long-term competitiveness were comprehensively studied. The results showed that pure electric transfer truck had a critical working distance of 23.7 km within 8 hours operation period, due to the short battery range and long charging time. Considering the total cost of ownership and future trend of carbon price increase, hydrogen-powered and pure electric transfer trucks would achieve competitive parity with LNG transfer trucks by 2030 and 2050 under short-distance (≤23.7 km) scenario. Under long-distance (>23.7 km) scenario, the competitive parity of hydrogen-powered transfer trucks would be 2035, but pure electric transfer trucks didn’t have competitive advantage for a long time. At present, the clean alternative of garbage transfer truck should prefer a “gas-primary, electric and hydrogen secondary” approach. And differentiated comprehensive energy supply facilities should be built based on scenario.

Methane emissions from domestic waste are one of the three major sources of methane emissions. In recent years, the amount of solid waste treatment from urban domestic waste in Beijing had grown rapidly, and it was expected that the amount of domestic waste removal and treatment would continue to operate at a high level in the coming years. It was particularly important to the control and comprehensive utilization of methane emissions. Based on the investigation of 10 domestic waste treatment facilities, included landfill sites, incineration plants, food waste and kitchen waste treatment plants, that produce and utilize methane within the Beijing area， the current utilization of methane was analyzed, and the problems in the production and utilization of methane in domestic waste were analyzed. The results indicated that the main processes for methane production in Beijing’s waste treatment were landfill gas and leachate treatment, included torch combustion and biogas power generation. Through using methane production prediction methods including LandGEM mathematical models, it was calculated that the theoretical methane production in the domestic waste field would accumulate to 2.363 billion cubic meters from 2023 to 2040. It was suggested that methane production should be controlled by source reduction, the anaerobic treatment scale of food waste and kitchen waste should be controlled based on the demand for aerobic composting. New technologies such as landfill gas emission reduction, optimal food waste and kitchen waste treatment, as well as methane reforming could be adopted to improve the utilization of methane in the domestic waste field, in order to achieve energy-saving and environmental protection effects.

The landfill mining and resource utilization of recyclable land resources，harmless and recycling of mineralized waste in landfill has significant economic and social benefits. The pain points in landfill management at home and abroad were comprehensively reviewed, with a keen focus on analyzing exemplar landfill treatment projects. It underscored the vital importance of pre-mining research, such as encompassing assessments of raw material recovery potential, economic viability evaluation and life cycle assessment. Based on the concept of comprehensive resource utilization of mineralized waste,the physical characteristics, heavy metal content, calorific value, and nutrient components of the mineralized waste in landfills were mainly described. Moreover, the mature resource utilization scheme was summarized, including humus reclamation technology and the thermal treatment of combustible components, thereby offering insights for the construction, excavation, and resource-efficient exploitation of large-scale landfills.

The mechanical biological treatment (MBT) technology, as a method for treating municipal solid waste, transforms it into solid recovered fuel (SRF), achieving the dual goals of waste resource utilization and reduction. The produced SRF could serve as a partial substitute for fossil fuels, thus delivering significant environmental benefits in reducing carbon emissions. The technology has been widely adopted in Europe, while its practical application in China is still in infancy. The Linyi municipal solid waste incineration plant was taken as a case study to analyze and summarize the process characteristics and treatment effects of MBT technology, as well as to explore the issues encountered in project implementation and propose corresponding strategies. The research findings revealed that the MBT system of the project consumed approximately 61.09 kWh of electricity per ton of waste processed, with an average processing cost of about 71.98 yuan/t. The resources generated from the treatment of municipal solid waste through MBT included metals and SRF, and the SRF product had a moisture content of around 30%, its low calorific value was above the design value of 10 454 kJ/kg. Through this analysis, it could provide reference for process design and operational analysis of other similar projects.

With the acceleration of the urbanization process and the proposal of the zero-waste city construction target, the recycling of construction and demolition waste (C&D waste) has become an important topic. Among all the types of C&D waste, the decoration waste needs to be more properly disposed because of the dispersed sources and complex components. Starting from the characteristics of decoration waste, the composition and particle size distribution of decoration waste were analyzed. According to the situation of complex components, the current situation of collection and transportation and the typical process route of “two-stage crushing + multi-stage sorting”were introduced. The optimization of treatment process in practical engineering application were summarized, the problems existing in the decoration waste recycling industry and feasible countermeasures were discussed, which provided references for the development of the decoration waste recycling industry.

During the dry anaerobic fermentation process of kitchen waste, the concentration of volatile fatty acids is an important monitoring index. By determining the concentration of volatile fatty acids daily, the operation situation of the anaerobic fermentation system could be understood. The Nordmann titration method, gas chromatography method, and colorimetric method were used to determine the concentration of volatile fatty acids in dry anaerobic fermentation process of kitchen waste. The experimental results showed that, due to the many pretreatment processes of the samples to be tested, the results of determination of volatile fatty acids by colorimetric method were unstable. Gas chromatography was cumbersome, had more sample pretreatment process, and the experiment time of a single sample was longer, which was suitable for determining the concentration of a single volatile fatty acid. Nordmann titration method could overcome these shortcomings and had the advantages of simple operation and high accuracy. Therefore, it was recommended to prioritize the use of Nordmann titration method to determine the concentration of volatile fatty acids in the anaerobic fermentation process of kitchen waste.

Anaerobic digestion (AD) of food waste could result in a large amount of biogas residue generation, which needs to be properly disposed. Biogas residue was prepared into hydrochar and pyrochar by hydrothermal and pyrolysis reaction, respectively. The effects of hydrochar and pyrochar on AD of food waste were compared. The results showed that compared with the control group (23.8 mL/g), the methane production of hydrochar group (dosage of 1, 5 and 10 g/L) was 24.0, 38.9 and 34.9 mL/g, which increased by 0.8%, 63.4% and 46.6%, respectively. The methane yield of pyrochar group (dosage of 1,5 and 10 g/L) was 29.7, 35.7 and 31.1 mL/g, which increased by 24.8%, 50.0% and 30.7%, respectively. Hydrochar and pyrochar amendment promoted the solubilization of organic matter. While the total relative abundance of hydrolytic acid-producing bacteria of Fastidiosipila, W5053, Propioniciclava, Actinomyces, and Norank_f__ST-12K33 increased from 73.0% to 84.6% and 82.0%, respectively. After adding hydrochar and pyrochar, the relative abundance of Methanosaeta was as high as 60.3% and 50.6% respectively, while the relative abundance of Methanobacterium was only 26.5% and 36.9%. Biochar from biogas residue could strengthen the AD of food waste, with the increase of dosage, methane production first increased and then decreased, the optimal dosage was 5 g/L. And the hydrochar performed better than pyrochar.

A sludge co-incineration project was taken as an example, the effect of mixed sludge on flue gas volume, pollutant concentration in flue gas, material consumption of flue gas purification and incineration ash production rate in waste incineration power plant were analyzed. The results showed that the change of flue gas volume was not significantly with the sludge co-incinerated. The SO2 concentration at the chimney outlet increased while it still could meet the emission standard. The concentration of other pollutants did not change significantly. For every 1% increase in sludge mixing ratio, slaked lime consumption increased by 0.14 kg/t (based on furnace materials), ammonia water consumption decreased by 0.22 kg/t (based on furnace materials), fly ash production rate increased by 0.04%, slag production rate decreased by 0.57%. Mixing one ton of sludge (moisture content was 78%) in this project would increase the operating cost of flue gas purification system by about 19.73 yuan.

With the gradual maturity of frequency conversion technology, most of the feedwater pumps in waste incineration power plants were replaced by constant speed feedwater pumps with variable frequency feedwater pumps, but the boiler feedwater system still adopted traditional feedwater control logic, which failed to fully tap the energy saving potential of variable frequency feedwater pumps. Through the overall analysis of the boiler feed water system of waste incineration power plant, the control logic of the original feed water system was reformed. At a single boiler scale, the drum water level was directly controlled by the frequency conversion feed water pump, and the feed water control valve was fully open. The average power saving of the water supply system was 0.28 kWh/t, the power saving rate was 7.2%. The variance of monthly unit water supply energy consumption was reduced from 0.064 to 0.033, and the stability of the water supply system was greatly increased, annual power saving of 109.5 MWh, equivalent to carbon reduction of 62.45 tCO2. Under multiple boiler scales, the pressure of the main pipe of the variable frequency feed pump changed with the pressure of the drum. The average power saving of the water supply system was 0.29 kWh/t, the power saving rate was 7.2%. The average unit feedwater variance was reduced by about 36%, the stability of the water supply system was greatly improved,annual power saving was 380.8 MWh, equivalent to carbon reduction of 217.17 tCO2 .

Chemical remediation of hexavalent chromium Cr(VI) contamination in soil involves two processes of reduction and stabilization. The aim of this study was to reduce the highly hazardous and highly mobile Cr(VI) in soil to the low hazardous and easily adsorbed trivalent chromium Cr(III), and further achieve stabilization. Chromium-contaminated soil from an industrial site in Ningbo, Zhejiang province, was selected for remediation. The effectiveness of different ratios of reducing agents, including oxalic acid, ferrous sulfate, urea, attapulgite clay, and zero-valent iron, was compared by measuring the Cr(VI) content in the soil. Based on reduction effectiveness and raw material costs, four different ratios of reducing agents were determined, namely 1% zero-valent iron, 1% ferrous sulfate, 0.5% attapulgite soil, and 3% ferrous sulfate. These four reducing agents were combined in pairs and added to the soil to compare their reduction effects. Four stabilizing agents, included biochar, quicklime, calcium-magnesium phosphate fertilizer and water-soluble silicon fertilizer were added to the reductant reduced soil with a mass ratio of 2%, and the Cr(VI) content in the soil was measured to evaluate the stabilizing effects. The results showed that the combination of 1% zero-valent iron and 1% ferrous sulfate achieved a reduction rate as high as 70.2%, demonstrated better reduction effects and lower costs compared to other treatments, so this combination was identified as the optimal reducing agent combination. The stabilization effect of 2% biochar was the best, and it was finally determined to be the stabilizer. In summary, the compound formulation of 1% zero-valent iron +1% ferrous sulfate and 2% biochar has the best reduction and stabilization effect on Cr(VI) which could be further verified in actual operation.

The factors affecting the sintering process of heavy metal contaminated soil and the environmental safety of sintering products are important issues for its resource utilization. Based on this, a simulation study on the resource utilization of sintered brick was carried out with As contaminated soil in Guangzhou(GZ), Changsha(CS), Suzhou(SZ) and Zibo(ZB) as raw material. The results indicated that the compressive strength of sintered bricks increased from 7.9% to 382.9% when sintering temperature increased from 900 ℃ to 950 ℃. The difference of soil mechanical composition leaded to significant difference in compressive strength of sintered bricks(P<0.01). The addition of 5%Na2CO3 and 5%Al2O3 could not only increase the compressive strength of the GZ soil sintered brick by 0.6 to 4.1 times, but also reduce the leaching concentration of As in the sintered brick by 88.4% to 98.8%, and the volatilization of As in the sintering process was reduced by 99.3%. Scanning Electron Microscope(SEM) and X-Ray Diffraction(XRD) results showed that the addition of compounds such as Na2CO3 and Al2O3 during sintering could lead to soil mineral changes, and could play multiple roles in filling, sealing and wrapping the lamellae gaps generated during sintering, thus significantly reduced the leaching concentration and volatilization of As.

To clarify whether the land resources could be reused safely after excavation in an informal landfill site, a landfill site in Jiashan county was taken as an example. Samples were collected from the excavation area of foundation pit and side wall, and the pH, organic matter and heavy metal （metalloid） concentrations of samples were detected. The results showed that mercury was not detected in the soil at the bottom and side wall of the foundation pit, the cadmium content was close to the background concentration, and the sample content was both below 0.23 mg/kg. The concentration trends of total chromium, copper, lead, and zinc in all samples were the same, and the maximum values were 99.0, 40.2, 43.0, and 201.0 mg/kg, respectively, with approximately 2.43, 1.05, 1.60, and 2.03 times over the background value. However, they were all lower than the requirements of the CJ/T 340—2016 Planting Soil for Green and GB 36600—2018 Soil Environmental Quality Risk Control Standard for Soil Contamination of Development Land, which could meet the requirements for green land use. The pH of the soil in this landfill site ranged from 6.77 to 8.26, with a relatively low organic matter content (average of about 7.96 g/kg) at the bottom of the foundation pit, which was much lower than the green land standard (12 to 80 g/kg). To make the land meet the green land requirements, it was necessary to increase the organic matter content. In addition, according to the Hakanson potential ecological risk assessment of soil heavy metals （metalloids）, the RI value was calculated to be 8.85 (RI<150), indicated that the ecological risk caused by eight heavy metals （metalloids） such as mercury, cadmium, arsenic, lead, copper, chromium, zinc, and nickel in the landfill site was of a mild level.

The amount of fly ash from domestic waste incineration is increasing year by year, with the majority being disposed of in landfills. However, the research on the soil mechanical characteristics of fly ash was relatively few, which was not conducive to guiding the landfill operation of fly ash. The geotechnical properties of stabilized incineration fly ash from a landfill in south China were tested, and were compared with the results of previous studies. The results indicated that the original fly ash from the municipal solid waste incineration could be classified as well-graded fine soil. After being stabilized and solidified by chemicals, lime, and cement, the particle size gradually increased and transformed into poorly graded fine sand, coarse sand, or even gravel. The geotechnical properties of fly ash in different landfills showed significant variation. The compression coefficient αv1-2 of fly ash from different landfills ranged from 0.26 to 2.96 MPa-1. The compressibility grade was medium to high. The cohesion force was 8.00 to 19.47 kPa, the friction angle was 32.50~36.30, and the unit weight was 11.0 to16.3 kN/m3.

The leachate treatment station of a large domestic waste incineration plant in Hangzhou was taken as an example. By monitoring the annual variation of leachate index of waste incineration plant, the seasonal variation characteristics of leachate was studied. In order to improve the treatment efficiency of leachate, the variation of pH, COD, ammonia nitrogen and biogas production of leachate were analyzed and discussed. The results showed that the pH, COD and ammonia nitrogen of the leachate of the waste incineration plant were greatly affected by the seasons, showed obvious seasonal differences. The monthly output of leachate of the incineration plant ranges from 26 000 to 39 219 tons, and the biogas produced by a ton of leachate ranged from 19.0 to 31.8 m3.

In recent years, with the increasing application of composite vertical barrier technology in pollution control, GCL composite vertical barrier technology has received more and more attention due to its excellent anti-seepage performance and high construction efficiency. It has been applied in pollution control projects in fields such as landfills, slag yards, and industrial pollution sites, achieving the goal of reducing soil and groundwater pollution and protecting the surrounding environment. The GCL composite vertical barrier technology is a new type of flexible composite vertical barrier technology. This article provides a detailed introduction to its technical principle, selection of composite anti-seepage structure materials, and construction process, further elucidating the pollution barrier mechanism of this technology, in order to enhance people’s understanding of this technology. In addition, through the introduction of engineering application cases, it is further demonstrated that GCL composite vertical barrier technology could effectively control pollution.

The pollution restoration and treatment project of a waste slag backfill area in South China was taken as the research object, its waste residue belongs to the class II of general industrial solid waste. According to the hydrogeology, pollution risk, operation and maintenance characteristics, combined with its pollution characteristics, the in-situ risk control technology of“HDPE flexible vertical anti-seepage around + horizontal anti-seepage on pile surface + ecological phytoremediation”was adopted for pollution remediation, and the restoration effect was analyzed. The results showed that for weakly permeable aquifers such as moderately weathered layers, equivalent seepage control could be achieved by increasing the depth of vertical seepage by using the principle of controlling the total amount of pollutants. Engineering measures for foundation reinforcement should be implemented based on the lithology and geology of the strongly weathered layer in the middle of the site. Finally, the project through the anti-seepage testing and evaluation, and achieved good in-situ isolation effect by HDPE flexible vertical seepage geomembrane, which had certain reference significance for the treatment and restoration project of the same type of waste residue polluted site.

Rural domestic waste management is the key link to implement the strategy of rural revitalization and improve the rural living environment. Through field investigation, questionnaire survey and data statistics, the current situation of rural domestic waste generation and classification in 11 rural areas (counties) in Xi’an after the implementation of the waste classification policy were compared and analyzed. And the source classification and classification treatment effect of rural domestic waste were analyzed. The results showed that the per capita daily production of rural domestic waste in the city ranged from 0.6 to 0.8 kg, primarily consisting of kitchen waste and other waste. There were still some problems in waste classification, such as poor effectiveness in source classification, lack of intrinsic motivation, and limited resource utilization of kitchen waste still exist, et al. Based on this, the corresponding countermeasures and suggestions were put forward.

At present, incineration has become the main disposal way of municipal solid waste (MSW). The number and disposal capacity of municipal solid waste incineration (MSWI) plants in Zhejiang province have improved significantly. Under the influence of conditions such as incineration overcapacity, huge differences of operating costs, insufficient scientific and technological innovation, it was crucial for the MSWI industry to optimize in fine management. Zhejiang province was taken as an example, the management status of its MSWI plants was analyzed, and suggestions from the aspects of planning and coordination, fine management, scientific and technological innovation were proposed. It was of great practical significance for the MSWI enterprises to improve the operational efficiency and MSW management departments to improve the regulatory system.