Aerobic and anaerobic methods of landfill leachate treatment: limitations and advantages

Landfilling is the most common and popular method to dispose of solid waste. The production of leachate from landfill sites is a major problem associated with the landfill technique of solid waste disposal. This chapter presents a general idea of the technical applicability of aerobic and anaerobic treatment of landfill leachate. This chapter reviews the performance, mechanism, application, limitations, and upgradation of various existing aerobic and anaerobic treatment techniques such as activated sludge (AS), sequencing batch reactors (SBRs), aerated lagoons, rotating biological contactors, upflow anaerobic sludge blanket (UASB) reactors, and constructed wetlands. The designing parameters such as hydraulic retention time (HRT) and organic loading rate and performance indicators are discussed. Among the aerobic and anaerobic treatment processes, AS, SBRs, and UASB are the most often used techniques. These techniques are effective in reducing chemical oxygen demand up to 90% and NH3-N up to 80%. Generally, the selection of the effective treatment technique for landfill leachate depends on leachate characteristics, technical applicability, HRT, economics, and further environmental impacts.