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Heterotrophic and elemental-sulfur-based autotrophic denitrification processes for simultaneous nitrate and Cr(VI) reduction Erkan Sahinkaya a,*, Adem Kilic b,c a

Istanbul Medeniyet University, Bioengineering Department, Goztepe, Istanbul, Turkey Harran University, Environmental Engineering Department, Osmanbey Campus, 63000 Sanliurfa, Turkey c Yeditepe Treatment Company, Kucukbakkalkoy, Atas‚ehir, Istanbul, Turkey b

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abstract

Article history:

Nitrate and chromate can be present together in water resources as nitrate is a common

Received 29 September 2013

co-contaminant in surface and ground waters. This study aims at comparatively evalu-

Received in revised form

ating simultaneous chromate and nitrate reduction in heterotrophic and sulfur-based

28 November 2013

autotrophic denitrifying column bioreactors. In sulfur-based autotrophic denitrification

Accepted 1 December 2013

process, elemental sulfur and nitrate act as an electron donor and an acceptor, respec-

Available online 12 December 2013

tively, without requirement of organic supplementation. Autotrophic denitrification was complete and not adversely affected by chromate up to 0.5 mg/L. Effluent chromate con-

Keywords:

centration was