title: Pilot-scale removal of chromium from industrial wastewater using the ChromeBac system.
abstract: The enzymatic reduction of Cr(VI) to Cr(III) by Cr(VI) resistant bacteria followed by chemical precipitation constitutes the ChromeBac system. Acinetobacter haemolyticus was immobilized onto carrier material inside a 0.2m(3) bioreactor. Neutralized electroplating wastewater with Cr(VI) concentration of 17-81 mg L(-1) was fed into the bioreactor (0.11-0.33 m(3)h(-1)). Complete Cr(VI) reduction to Cr(III) was obtained immediately after the start of bioreactor operation. Together with the flocculation, coagulation and filtration, outflow concentration of less than 0.02 mg Cr(VI)L(-1) and 1mg total CrL(-1) were always obtained. Performance of the bioreactor was not affected by fluctuations in pH (6.2-8.4), Cr(VI) (17-81 mg L(-1)), nutrient (liquid pineapple waste, 1-20%v/v) and temperature (30-38 degrees C). Standby periods of up to 10 days can be tolerated without loss in activity. A robust yet effective biotechnology to remove chromium from wastewater is thus demonstrated.
authors.affiliation: Department of Chemistry, Faculty of Science, Universiti Teknologi Malaysia, 81310 Skudai, Johor, Malaysia.
authors.forename: Wan Azlina
authors.initials: WA
authors.lastname: Ahmad
authors.forename: Zainul Akmar
authors.initials: ZA
authors.lastname: Zakaria
authors.forename: Ali Reza
authors.initials: AR
authors.lastname: Khasim
authors.forename: Muhamad Anuar
authors.initials: MA
authors.lastname: Alias
authors.forename: Shaik Muhammad Hasbullah Shaik
authors.initials: SM
authors.lastname: Ismail
mesh_terms: D001673:Biodegradation, Environmental; D019149:Bioreactors / Q000382:microbiology; D002857:Chromium / Q000302:isolation & purification*; D005374:Filtration; D005427:Flocculation; D007220:Industrial Waste / Q000032:analysis*; D010865:Pilot Projects; D014865:Waste Disposal, Fluid / Q000379:methods*; D014874:Water Pollutants, Chemical / Q000302:isolation & purification*; D018508:Water Purification / Q000379:methods*
chemical_list: D007220:Industrial Waste; D014874:Water Pollutants, Chemical; D002857:Chromium