Removal of Hexavalent Chromium from Wastewater Using a New Composite Chitosan Biosorbent

• Published in: Environmental science & technology Vol. 37; no. 19; pp. 4449 - 4456
• Main Authors: Boddu, Veera M, Abburi, Krishnaiah, Talbott, Jonathan L, Smith, Edgar D
• Format: Journal Article
• Language: English
• Published: Washington, DC American Chemical Society 01-10-2003
• Subjects: Adsorption; Aluminum Oxide - chemistry; Applied sciences; Biological and medical sciences; Biological treatment of waters; Biotechnology; Carcinogens, Environmental - isolation & purification; Chelating Agents - chemistry; Chitin - analogs & derivatives; Chitin - chemistry; Chitosan; Chromium; Chromium - isolation & purification; Environment and pollution; Exact sciences and technology; Fundamental and applied biological sciences. Psychology; Industrial applications and implications. Economical aspects; Industrial wastewaters; Models, Theoretical; Pollution; Temperature; Waste materials; Wastewaters; Water Purification - methods; Water treatment; Water treatment and pollution; Aluminium oxide; Liquid solid adsorption; Adsorption isotherm; Adsorption capacity; Metallurgical industry; Bioadsorbents; Coatings; Oxide ceramics; Heavy metal; Operating conditions; Biological purification; Regeneration; Biosorption; Industrial waste water; Biopolymer; Chitosan; Waste water purification; Chromium VI
• ISSN: 0013-936X; 1520-5851
• DOI: 10.1021/es021013a

A new composite chitosan biosorbent was prepared by coating chitosan, a glucosamine biopolymer, onto ceramic alumina. The composite bioadsorbent was characterized by high-temperature pyrolysis, porosimetry, scanning electron microscopy, and X-ray photoelectron spectroscopy. Batch isothermal equilibrium and continuous column adsorption experiments were conducted at 25 °C to evaluate the biosorbent for the removal of hexavalent chromium from synthetic as well as field samples obtained from chrome plating facilities. The effect of pH, sulfate, and chloride ion on adsorption was also investigated. The biosorbent loaded with Cr(VI) was regenerated using 0.1 M sodium hydroxide solution. A comparison of the results of the present investigation with those reported in the literature showed that chitosan coated on alumina exhibits greater adsorption capacity for chromium(VI). Further, experimental equilibrium data were fitted to Langmuir and Freundlich adsorption isotherms, and values of the parameters of the isotherms are reported. The ultimate capacity obtained from the Langmuir model is 153.85 mg/g chitosan.