Performance of Anaerobic Sequencing Batch Reactor in Biomethane Recovery and Biohydrogen Recovery From Distillery Wastewater

摘要

Distilleries are one of the most polluting industries generating large volumes of carbohydrate rich wastewater. Studies were made to investigate the performance of anaerobic sequencing batch reactor (ASBR) in the recovery of biomethane and biohydrogen from distillery wastewater. Investigation was carried out in 2 laboratory scale ASBRs with a working volume of 3.5 L. Biomethane reactor was seeded with anaerobic distillery sludge and biohydrogen reactor was seeded with pretreated anaerobic distillery sludge. Dark fermentation process was employed for biohydrogen production. Both the reactors were operated in 8 hr cycles with 3 sequences per day. Each sequence of operation comprised of 4 cyclic steps: Feed, react, settle and discharge. The reactors were operated by increasing the organic loading rate and decreasing the hydraulic retention time from 96 to 72 hr, 48 hr, 36 hr and 24 hr. Gas production trend and cumulative gas production were studied at various hydraulic retention times. Experimental data recorded a maximum volumetric gas production rate of 1.98 m~3/m~2/d and 2.023 m~3/m~2/d in the methane reactor and hydrogen reactor, respectively. Maximum specific gas production was observed to be 0.04841 m~3/kg COD removed in the methane reactor and 0.03998 m~3/kg COD removed in the hydrogen reactor. Substrate degradation rate was found to vary from 13.48 kg COD/m~3/d at OLR of 22.75 kg COD/m~3/d to 32.12 kg COD/m~3/d at OLR of 91 kg COD/m~3/d in the methane reactor and from 12.65 kg COD/m~3/d at OLR of 24 kg COD/m~3/d to 23.52 kg COD/m~3/d at OLR of 96 kg COD/m~3/d in the hydrogen reactor. The removal of TS, VS, TSS, TDS and COD were observed to be higher in the ASBR used for methane recovery.