Effect of NaCl and Na2SO4 on the biodecolourization of K-2BP by Halomonas sp. GYW

In this paper, the effect of NaCl and Na2SO4 on the biodecolourization of reactive brilliant red K-2BP by a Halomonas sp. GYW (EF188281) was investigated in details. The decolourisation efficiency and the oxidation-reduction potential (ORP) change were explored during the decolourization process. The results from sequencing batch tests showed that Na2SO4 influenced the decolourization efficiency more slightly than NaCl in different synthetic dye solutions with different mixtures of Na2SO4 and NaCl. In the dye solutions with the same salt concentration or the same Na+ concentration, high Na2SO4 concentration did not inhibit the decolourization process and even stimulated the decolourization efficiency of reactive brilliant red K-2BP. Compared to NaCl system, the addition of Na2SO4 increased the ORP values about 35 mV, which agreed with the theoretic analysis of Gibbs function. This study improved our knowledge of azo dye decolourization under high salinity conditions and provided efficient option for the treatment of azo dye wastewater.