Zinc and copper inhibition on acidogenesis in anaerobic treatment

Abstract

Anaerobic treatment of industrial and domestic wastewaters has been a growmgconcern in recent years owing to many advantages. However the problems which rose inthe conventional applications of anaerobic treatment have led the researchers to develop anew technique called as two-phase concept which can basically be defined as theseparation of acidogenesis and methanogenesis steps of anaerobic digestion.The aim of this study is to investigate the inhibition effects of Zn and eu on theacidogenesis stage of anaerobic digestion. For this purpose anaerobic seed sludge wasacclimated to glucose in lab-scale conditions and then the inhibition effects of selectedheavy metals were investigated by gas chromatographic methods. The major VF As weredetected as butyric, acetic and propionic acids with the negligible amounts of isovalericand valeric acids. The relative inhibition of tested metals was found as Cu)Zn. Mixtures ofzinc and copper exhibited synergistic effects and acetic acid production mechanism wasfound more vulnerable to tested metals than that of the butyric acid. Therefore control ofzinc and copper in the acidogenesis phase would be beneficial to achieve more stable andefficient anaerobic degradation which makes it preferable as an energy saving process.Keywords: Zinc, Copper, Inhibition, Acidogenesis, Anaerobic Digestion