CLEANING OF WASTE WATER FROM COPPER AND ZINC: EFFECTIVE TECHNOLOGY

Abstract

The environment and water objects are increasingly soiled by wastewaters and sludge coming from galvanic production containing compositions of several rare and precious metals such as Cu, Zn, Ni, Co, Cr etc. At the same time these wastes present mostly toxic matters which endanger environment and human health .The industrial enterprises pay special attention to the treating and utilization of sludge containing heavy metals which present precious secondary row materials. Especially acute is the problem of energy cost reduction on all stages of sludge treatment technology. It is envisaged to organize galvanic processes which are aware of environmental aspects. The main stages of reagent water cleaning consist of: contact sedimentation (cementation) of cupper ions through zinc powder ; separation of zinc from the solution during electrolysis and returning the cleaned water to the technological cycle. The principal sources of the economic effect (Pp) present: extraction of cupper and zinc from galvanic bath solution; reduction of energy cost connected with solution cleaning ; reduction of penalties for environment soiling, organizational and technical measures aimed at the lowering the cleaning expanses. The calculations performed showed the use of reagent cleaning of water wastes from cupper and zinc in a closed water supply cycle to be effective and profitable