Abstract: In order to explore feasible technology for in situ reduction of secondary pollutants such as leachate and landfill gas from domestic waste landfills in arid and cold regions. The semi-aerobic landfill project demonstration was built in a landfill in the northwest region, with engineering measures of leachate recharge, as well as active negative pressure collection of landfill gas and biological cover filtration treatment. At the same time, traditional anaerobic landfill was constructed as the control group. The design scale of the demonstration landfill was 20 t/d, with a total of 188 days of operation and a total landfill volume of 3 849.84 tons. The results of the 18 samplers indicated that the average oxygen concentration was 6.7%. In this project and in anaerobic landfill in control group, the ratios of CODCr concentration of leachate were 1.79 and 0.41, the ratios of TN were 2.61 and 0.93, respectively, at the initial stage of landfill and the end of the operation period. The average methane concentration was 20.11% in each gas guide well during landfill operations, while it was 31.96% after 21 weeks when landfill was over, 18.25% with the blower collected gas, and decreased to 3.43% after biofiltration. The above showed that semi-aerobic environment had been formed with the design of the ventilation channel of the landfill body of the gas guide well, drainage pipe and gas guide well, which could be used in the domestic waste landfill in arid and cold regions, and it had the effect of reducing the environmental load of leachate and landfill gas in situ.

Key words: semi-aerobic landfill, arid and cold regions, practical application research, in situ reduction