STUDY ON REMOVAL OF HEAVY METALS Pb, Cd, Hg AND Cr IN LEACHATE USING ANAEROBIC BIOTECHNOLOGY WITH UASB REACTOR

Abstract

Although the presence of sulfate in the leachate under anaerobic conditions was accompanied with biological sulfate reduction process, resulting in H2S formation, which caused a number of problems such as methanogenic toxicity, corrosion, malodou.. the experiments carried out both in batch types and continuous highrate anaerobic reactor of UASB type had shown that biological sulfate reduction could be used, through its product S ions, for removal of the heavy metals such as Hg, Cd, Pb contained in the leachate to reach the National Standards for the Industrial Effluents TCVN 5945, 1995. Removal of these heavy metals in form of metal sulfides Mes, having rather low solubility and higher stability within rather wider pH range, as compared to MeCO3 or Me(OH)2 , occurred at a very high efficiency and rate.