Effect of Metals on Decolorization of Reactive Blue HERD by Comamonas sp. UVS

Comamonas sp. UVS was able to decolorize Reactive Blue HERD (RBHERD) dye (50 mg L −1 ) within 6 h under static condition. The maximum dye concentration degraded was 1,200 mg L −1 within 210 h. A numerical simulation with the model gives an optimal value of 35.71 ± 0.696 mg dye g −1 cell h −1 for maximum rate ( V max ) and 112.35 ± 0.34 mg L −1 for the Michaelis constant ( K m ). Comamonas sp. UVS has capability of decolorization of RBHERD in the presence of Mg 2+ , Ca 2+ , Cd 2+ , and Zn 2+ , whereas decolorization was completely inhibited by Cu 2+ . Metal ions also affected the levels of biotransformation enzymes during decolorization of RBHERD. Comamonas sp. UVS was also able to decolorize textile effluent with significant reduction in COD. The biodegradation of RBHERD dye was monitored by UV–vis spectroscopy, FTIR spectroscopy, and HPLC.