Cometabolic reduction of bromate by a mixed cultur

Authors: C G van Ginkel B J Middelhuis F Spijk W R Abma

Publish Date: 2004/12/17

Volume: 32, Issue: 1, Pages: 1-6

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Abstract

The discharge of bromate a suspected carcinogen will be restricted in the near future To assess the possibility of biotechnological treatment of bromatecontaining wastewaters the removal of bromate by chloratereducing microorganisms was studied The removal of bromate and chlorate was studied in laboratory gaslift bioreactors supplied with hydrogen gas as electron donor in the absence of molecular oxygen In these reactors bromate was reduced cometabolically by chloraterespiring microorganisms To allow the cometabolic reduction of bromate a chloratebromate molar ratio of at least 31 was required The cometabolic conversion permitted almost complete reduction of bromate into bromide at hydraulic retention times of at least 6 h Optimal bromate reduction activity was observed at approximately 35°C The pH optimum was between 7 and 8 Bromate reduction in excess of 80 and a maximum bromate reduction rate of 23 g l−1 day−1 in a pilotscale gaslift bioreactor demonstrates that the process is sustainable

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