Application of Kaolin for Control of Heavy Metals in Anaerobic Sludge Digestion

摘要

Six laboratory-scale anaerobic digesters were used to evaluate the potential of kaolin addition for the control of heavy metal toxicity. Adsorption isotherms were obtained for the kaolin-metal system in solutions of the individual metals, nickel, copper, chromium and zinc and in mixtures of the metals. The adsorption-ion exchange capacity of kaolin for the metals decreased in the order Cr(III) > Cu > Ni > Zn. The kaolin fed digesters became acclimated to slightly higher concentrations of metals than the non-kaolin fed unit and performed nearly as well as the non-metals fed digesters.