Study On The Disposal Of Mature Landfill Leachate By Aged Refuse Bioreactor

With the development of our national economy and the improvement of people’s living standard, municipal solid wastes has become increasingly produced. Landfill is the technology used most widely to dispose the solid refuse in China. Sanitary landfill is the main disposal technology of municipal solid waste (MSW). As a mature and less expensive one, this technology is proper to our country well. However, the leachate generated from landfill will cause serious pollution to the environment if discharged without treatment. The traditional landfill leachate treatment technologies face the challenge on nitrogen pollutants removal because the effluent is hard to meet The National Discharged Standard (GB16889-2008). Therefore exploring new landfill leachate treatment technology of nitrogen pollutants removal has significant in practical application.In recent years, aged-refuse bioreactor technology has been gradually developed. The aged-refuse bioreactor packed with10years of stabilized garbage as filler to treat landfill leachate. The aerobic microorganisms on the upper surface and the anaerobic microbial on the lower surface, and combinating with particles adsorption, ion exchange and chelation to remove the pollutants, therefore aged refuse bioreactor has a good performance on treating landfill leachate. Now it has been applied in practical engineering. But there were few studies on the mature landfill leachate treatment with the use of the age-refused bioreactor, especially using anaerobic ammonia oxidation technology to treat leachate.In this research, the aged refuse used to fill aged-refuse bioreactor were taken from Shanghai laogang landfill. The study of aeration and circulation on the pollutant removal were investigated. By controlling the appropriate temperature, ammonia nitrogen and nitrite nitrogen concentration ratio to meet the necessary conditions of anaerobic ammonia oxidation (Anammox), an Anammox reactor was constructed and operated to study the total nitroge removal of the mature landfill leachate, which would provide the reference on engineering application. The results showed as follows:(1)The aged refuse bioreactor could improve the total nitrogen removal efficiency of pollutants by aeration from24.3%to33.1%. It shows that suitable aeration can improve nitrogen removal efficiency of pollutants. Whether aeration or not, it appeared the actual total nitrogen removal rate far exceed the theoretical value, the total nitrogen imbalance happened.(2)The results showed that the circulation or not has no obvious impact on the total nitrogen removal efficiency. The circulation on the total nitrogen removal efficiency of pollutants is not significant under the hydraulic loading of51L/d*m2. the total nitrogen imbalance appeared again.(3)At the influent landfill leachate C/N ratio about0.1, the aged-refuse bioreactor can remove total nitrogen of the mature leachate amount to54%. The polymerase chain reaction (PCR) and15N isotope tracer technology were used to examine the sample from the reactor, and the anaerobic ammonium oxidation bacteria was found, the results showed that the anaerobic ammonium oxidation played some roles of deniftrification.(4)The anaerobic ammonia oxidation reactor experiments show that with the total nitrogen loading increases from0.74g/kg (vs) to2.03g/kg (vs), the total nitrogen removal rate dropped from96%to62.2%, it is suggested that the nitrogen loading has important impact on total nitrogen removal.The results of this study show that, constructed aged-refuse bioreactor can remove the nitrogen of mature landfill by the anaerobic ammonium oxygen and denitrification synergy. This technology can not only reuse waste, but also solve the problem of the traditional denitrification processing without carbon source addition, which could remove nitrogen with highly efficient with low energy consumption, which has potential application prospect.