Tractability study of sanitary landfill leachates: emphasis on combined treatment with sanitary sewage in aerobic systems

Abstract

Sanitary landfill leachates are dark coloured and pollutant wastewaters, due to the presence of: biodegradable and refractory organic matter (as humic substances), total dissolved solids (TDS), heavy metals and high ammonia concentration [1]. This research is focused on leachates treatment, in order to meet the discharge standards of CONAMA Resolution 397/08. Thus, the following physico-chemical pretreatments will be evaluated: air stripping (with chemical precipitation), for ammonia removal; advanced oxidative processes, for color and refractory matter removal, verifying the influence of TDS (as chloride); filtering membranes and electrolytic process, for TDS removal. The leachates (raw and pretreated by chemical precipitation) tractability will be evaluated in: activated sludge in bench (batch regime) and pilot scales (continuous flow regime), and in a pilot scale submerged aerated biofilter. If this tractability is confirmed, combined units will be evaluated, as for example: activated sludge or submerged aerated biofilter and physico-chemical processes. At last, more emphasis will be given to the leachates (raw and pretreated by air stripping) combined treatment in aerobic systems (actived sludge and submerged aerated biofilter) with sanitary sewage (raw and pretreated by anaerobic reactors). This project also aims to verify if there is or not leachates dilution, instead of its real treatment with sanitary sludge. It will be also evaluated if there is ;; accumulation of heavy metals in aerobic sludge, in order to verify if this sludge could be used in agriculture, according to specifications of CONAMA Resolution 380/06. These experiments will be guided by physico-chemical analysis and microbiological exams, for identification of operational conditions. (AU)