Use of low-cost biological wastes and vermiculite for removal of chromium from tannery effluent

• Published in: Bioresource technology 2005-02, Vol.96 (3), p.309-316
• Main Authors: Sumathi, K.M.S., Mahimairaja, S., Naidu, R.
• Format: Article
• Language: English
• Subjects: Adsorbents; Adsorption; Aluminum Silicates - chemistry; Biological and medical sciences; Biological treatment of waters; Biosorbents; Biotechnology; Charcoal; Chromium; Chromium - chemistry; coir; coirpith; Distribution co-efficient; Environment and pollution; Freundlich adsorption isotherm; Fundamental and applied biological sciences. Psychology; Industrial applications and implications. Economical aspects; Low-cost biological wastes; Oryza sativa; rice hulls; sawdust; sorption isotherms; Spectrophotometry, Ultraviolet; Tannery effluent; tannery effluents; Tanning; Vermiculite; Waste Disposal, Fluid - instrumentation; Waste Disposal, Fluid - methods; Waste Products; wastewater treatment; Wood
• ISSN: 0960-8524; 1873-2976
• DOI: 10.1016/j.biortech.2004.04.015

Biological wastes (sawdust, rice husk, coirpith and charcoal) and a naturally occurring mineral (vermiculite) have been tested for their effectiveness in removing Cr from tannery effluent through batch and column experiments. The adsorption capacities of the substrates were also evaluated using isotherm tests and computing distribution co-efficient. The sawdust exhibited a higher adsorption capacity ( k=1482 mg kg −1), followed by coirpith ( k=159 mg kg −1). The biosorbent and mineral vermiculite in columns were found very effective in removing Cr from tannery effluent. About 94% removal of Cr was achieved by a column of coirpith, and equally (93%) by a column containing a mixture of coirpith and vermiculite. This study showed that biological wastes are potential adsorbents of Cr, which could be successfully used to reduce the Cr concentrations in tannery effluent.