Tanneries: A Short Survey of the Methods Applied for Wastewater Treatment

Abstract

A short description of the tannery production process is given, mentioning the main points related to an effluent discharge. Qualitative and quantitative data are presented and several methods used for wastewater treatment are also reviewed. It is stated that biological systems (activated sludge) cannot be operated in the same way as for municipal effluents, since tne main pollutants (Cr - salts, sulfides) negatively affect the action of microorganisms. Therefore, a pretreatment step is required prior to the effluent discharge into a municipal treatment plant. Another problem is the treatment and disposal of the precipitated sludge. Several already applied methods trying to eliminate the problem are discussed. All represented data are taken from research studies published in international 1iterature.