Removal of Heavy Metals in Municipal sludge by Using Acetic Acid-H_2O_2- Ferrite Way

摘要

Removals of copper and zinc from municipal sludge from Tianjin Dongjiao Sewage Treatment Plant by using acetic acid - H_2O_2 way and the removals of heavy metals from municipal sludge extract fluid by using improved acetic acid- ferrite way were studied in experiment. The better technique condition to remove copper and zinc was that the quality concentration of acetic acid was 2mol/L, the ratio of sewage sludge, H_2O_2 and acetic acid was 1:2:50, the reaction time 4 hours in room temperature, and the removal rates of copper and zinc were over 95%. Using improved ferrite way and lime milk as neutralization, Cu, Zn, Cr, Ni, Cd, Pb could be removed from municipal sludge filtrate caused by acetic acid- H_2O_2, the removal rates of Cu, Zn, Cr, Ni, Cd, Pb were 94%, 98%, 86%, 92%, 89%, 99% and the filtrate could be dicharged legally. The best technique condition was that the initial concentration of FeCl_3/FeSO_4 was 0.10/0.05mol/L, the added Fe~(2+):Fe~(3+) (mol value) =1:2, Fe~(3+)/M~(n+) (Cu~(2+),Zn~(2+)) =10, the pH value was 9, reaction temperature was room temperature.