Study on the Solidification/Stabilization Treatment of Tannery Sludge

Abstract

Sludge from tannery was solidified and stabilized by using lime, PFA and cinder as the solidifying agents，investigation of solidifying agents affect toxic heavy metals in tannery sludge and the optimum conditions of sludge solidification/stabilization were analyzed. The results showed that under the dosage of lime, PFA and cinder were 0.12kg/kg, 0.02kg/kg and 0.08kg/kg respectively, and curing time was 6 days, the compressive strength of the solidified sludge block reached 884KPa while the moisture content of the solidification block was 30.2%，which met with the standards of landfill. Compared with the untreated tannery sludge，the concentration of Cu、Pb、Zn、Ni and COD of the leaching from the sludge solidification block was reduced by 92.1%、96.7%、92.8%、88.9% and 75.9% respectively，the Cr、Cd、and Mn were undetectable.When lime and PFA ratio was 6:1, the solidified block have good synergistic solidification effects.