The primary goal of this work was to evaluate the technical and economical feasibility of coagulant recovery from acidification of water treatment plant sludges, and the use of recovered coagulants in wastewater treatment. Acidification bench tests were conducted in order to study the regeneration conditions, the recovered coagulant quality and the remaining sludge. The recovered coagulant had a satisfactory behavior in the treatment of UASB reactor effluent and was observed significantly suspended solids reductions in the water treatment plant sludges. On the economical evaluation it was verified that considering the costs decrease due to the sludge reduction, the recovered coagulant production cost was very similar to commercial coagulants cost. Thus, it was concluded that nowadays this technology must be considered as a potential alternative for the treatment and reuse for water treatment plant sludges, regarding to technical and economical aspects.
Coagulant recovery; water treatment plant sludge; wastewater treatment
