Journal of Zhejiang University SCIENCE
(ISSN 1009-3095, Monthly)

2005   Vol. 6B   No. 6   p.574-579

Study on anaerobic treatment of wastewater containing hexavalent chromium

XU Yan-bin^†, XIAO Hua-hua, SUN Shui-yu

(Faculty of Environmental Science and Engineering, Guangdong University of Technology, Guangzhou 510090, China)
^†E-mail: hopeybxu@tom.com
Received Oct. 28, 2004; revision accepted Apr. 21, 2005

Abstract: A self-made anaerobic bio-filter bed which was inoculated with special sludge showed high efficiency in removing hexavalent chromium. When pump flow was 47 ml/min and COD_Cr of wastewater was about 140 mg/L, it took 4 h to decrease the Cr⁶⁺ concentrations from about 60 mg/L to under 0.5 mg/L, compared with 14 h without carbon source addition. Cr⁶⁺ concentrations ranged from 64.66 mg/L to 75.53 mg/L, the system efficiency was excellent. When Cr⁶⁺ concentration reached 95.47 mg/L, the treatment time was prolonged to 7.5 h. Compared with the contrast system, the system with trace metals showed clear superiority in that the Cr⁶⁺ removal rate increased by 21.26%. Some analyses also showed that hexavalent chromium could probably be bio-reduced to trivalent chromium, and that as a result, the chrome hydroxide sediment was formed on the surface of microorganisms.

Key words: Hexavalent chromium, Wastewater, Anaerobic, Bio-filter bed, Hexavalent chromium bio-removal
doi:10.1631/jzus.2005.B0574             CLC number: X703.1