Study On On-site ABR Treatment Of Night Soil Wastewater And The Design Of The Collected Landfill Leachate Treatment

This paper presented two major works. One was the research of the underground treatment of leachate produced from the kitchen garbage and on-site treatment of night soil, the other was the design and economic analysis of treatment of landfill leachate.(1) On-site dispersed treatment of wastewater from garbage wastewaterTarget Fabricate a set of apparatus suitable for the high-strength wastewater produced from kitchen garbage and on-site treatment of night soil, and meet the standard for discharge.Method Select modified underground anaerobic baffled reactor suitable for the characteristic of water as the emphasis in this reaearch. This work has been designed lab-scale reactor and bench-scale reactor.Result After nearly two years work, we finished the design and manufacture of the lab-scale and bench-scale reactors. It revealed that COD removal rate of ABR could reach 90%. The start-up of the reactor could accomplish in one or two weeks when inoculated granule sludge. ABR had a good ability to tolerate the shock load of toxic pollutants, and keptthe COD effluent at 200mg/L, which could meet the discharge standard after sand filter. pH increased stepwise longitudinal along the reactor, the pH of effluent was stable at 6.8~7.2.Post treatment was added to remove ammonia and reduced COD. The cost-benefit analysis demonstrated that the system could make profit at the scale of 100 households. The more the scale, the shorter the durance to get back the investment. When it had reached 5000 households, IRR is 45%, NPV is 25.5591 million yuan. (2) The collected treatment of landfill leachateAiming to the high-strength, complicated, hard-to-treat characteristics of landfill leachate, we designed a set of technics which contained the physics, physic-chemical, anaerobic and aerobic treatment. The overall volume is 60m3/h, the effluent can fulfill the 3rd discharge standard GB8978-1996. The working volume of buffer tank is 5000m3, we took the innovative tech of floating cover, which can make the whole tank in anaerobic phase. It can not only solve the odor in the operation of landfill, but degrade part of COD, and collect methane.The analysis of financial showed that the IRR of this project was 6.58%, NPV(I=4%) was 1.5108 million yuan, the durance of static investment was 15.76 years; the sensitive analysis indicated, the major factor influencing the profit was the income of sale. The innovative idea of this thesis The first time to use ABR to treat high-strength garbage and nightsoil wastewater and complete an underground treatment facility, the first time in our country to utilize the floating cover in the design of landfill leachate buffer tank.