Regeneration and reuse of leachate from a municipal solid waste landfill.

Landfill leachate is deep brown in color with extremely complex composition and difficult to treat in order to meet the effluent standards. The leachate of Keelung City Tien Wai Tien landfill has an average flow of 350 CMD. In the present study following serially connected devices: Activated sludge/contact aeration (AS/CA) combined system, reverse osmosis (RO) and an ammonia stripping tower were used to treat the leachate. After treatment, the COD (removal rate of 91%), BOD (removal rate of 83%), SS (removal rate of 86%) and NH(4+)-N level (removal rate of 98%) significantly reduced in the leachate. The treated effluent was further recycled and used as RO back washing water and for sprinkling roads and watering plants in Keelung City. It is further required to evaluate whether the treated effluent can be reutilized for agriculture and extinguishing fire during shortage of water.