Treatment Of Tannery Effluent By Chemical Precipitation

Abstract

Industrialization and population in crease is destroying the environmental quality. Chrome tanning discharges large quantities of effluent containing up to 180 mg/l of chromium while the permissible limit is 2.0 mg/l. along with the chromium other pollutants are also present Hexavalent chromium are highly toxic and accumulative in nature. Cr (vi) pollution has become one of the world's most serious environmental concerns due to its long persistence in the environment and highly deadly nature in living organisms. The hexavalent chromium is carcinogenic, genotoxic and mutagenic (1). The most economic and simple technique  consists of alkali precipitation, lime, caustic soda and mixture have been used in the present study in the temperature range between 25 to 100⁰C.

Key words: Hexavalent chromium, effluent, caustic soda, lime, temperature, permissible.