Arsenic remediation using anaerobically digested sewage sludge

S. Nair1, P. Pullammanappallil1,* and P. Singh2

1Centre for Organic Waste Management, Murdoch University, Murdoch, WA 6150 Australia
2Department of Chemistry, Murdoch University, Murdoch, WA 6150 Australia

Accepted 30 July 2004


Anaerobically digested sewage sludge, which is a mixed culture, was used as the inoculum for the volitilization of inorganic arsenic. The sludge was initially activated by feeding with a nutrient solution containing molasses. Activity of the culture was monitored by measuring the gas production from the digester. Inorganic arsenic at different concentrations was spiked into the bioreactor and its effect on gas production was monitored. It was found that arsenic was distributed in solid, liquid and gaseous forms. The results indicated that arsenic concentration up to 34 ppm was not toxic to the microorganisms. The present study confirms that microorganisms in anaerobically digested sewage sludge volatilizes inorganic arsenic.

Keywords: Arsenic; Anaerobic digestion; Sewage sludge

* Corresponding author
   E-mail : pratap@murdoch.edu.au