Removal of Heavy Metals in Municipal Sludge by Using Acetic Acid-H2O2- Ferrite Way
Removals of copper and zinc from municipal sludge from Tianjin Dongjiao Sewage Treatment Plant by using acetic acid - H2O2 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, H2O2 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- H2O2, 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 FeCl3 /FeSO4 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.