Sulphate reduction optimization by sulphate-reducing bacteria in a glucose-fed anaerobic moving bed biofilm reactor

摘要

Several factors affecting sulphate reduction by sulphate-reducing bacteria in a glucose-fed anaerobic moving bed biofilm reactor are investigated in this study. In the operation regimes without vitamin B12 supplementation into the influent of the glucose-fed reactor, its sulphate removal efficiency is high and up to 86% when temperature varies within 34℃-36 ℃; only when influent pH of the reactor is in the ranges of 6.28-6.9, its sulphate removal rate is up to the maximum, 81%-86%, and lowering influent pH from 6.28 to 3.08 or increasing influent pH from 6.9 to 7.6 can reduce the sulphate removal efficiency of the reactor; decreasing the hydraulic retention time from 12 h to 4 h leads to a rapid reduction of sulphate removal efficiency of the reactor; increasing COD/sulphate ratio of influent from 1.0 to 3.0 can raise the sulphate removal efficiency of the reactor, and when the ratio of influent is over 2.5 the sulphate removal efficiency of more than 96% can be achieved. Vitamin B12 supplementation into the influent of the glucose-fed reactor for sulphate reduction can get some meaningful results, which can not only help the well-buffered pH system of the reactor to be quickly established and also make the reactor get a high sulphate reduction efficiency of more than 90% even if it is fed with acidic wastewater with pH of 3.08-6.90. The maximum sulphate loading rate of 7.16 g/cm~3·d is achieved within 260 operation days of the reactor, and its sulphate removal efficiency is up to 85%-95% at this loading rate.