Biological reduction of acid red 14 by elemental sulfur and methanol-based reactors

In this study for the first time, biological reduction of the acid red 14 in elemental sulfur-based anaerobic reactor was studied. two up-flow packed bed reactors were investigated in parallel for 95 days. sulfur and methanol were used as electron donors in these reactors and the performance of the sulfur-based reduction process was investigated in comparison with a conventional electron source - methanol. the reactors were operated in 7 different periods, the influent dye concentration was kept at 5-10 mg/l and hrt was set to 12-24 hours. while influent acid red 14 concentration was 10±0.14 mg/l, it was reduced to 1.3±0.2 in the methanol-based reactor and 2.05±0.2 in the sulfur-based reactor. elemental sulfur was used for the first time in and the effect of sulfur oxidation in dye reduction process on sulfate and alkalinity production was also investigated.