[Feasibility of sewage sludge used as filling material in permeable reactive barrier]

Permeable reactive barriers (PRB) have been used widely as an alternative technique to treatment of acid mine drainage (AMD). Selection of the appropriate filling materials is the most important procedure to application of this treatment. Batch adsorption tests and bacteria culture batch tests were conducted to assess the possibility of sewage sludge served as filling material for PRB. Results from batch adsorption tests showed that the maximum adsorption capacities of the sewage sludge were 13.62 mg x g(-1) (Zn2+) and 15.60 mg x g(-1) (Cd2+). Bacteria culture batch tests indicated that SO4(2-) concentrations in reactors decreased from initial concentrations of 700 mg x L(-1) to below 300 mg x L(-1). Sulfate removal efficiency ranged from 60% to 70%. Fe and heavy metals, including Zn and Cd, were removed completely in two reactors. This study suggested that sewage sludge is a suitable filling material for PRB.