Perchlorate bioreduction in UASB reactor: S2--autotrophic granular sludge formation and sulphate generation control

Abstract

ABSTRACT Perchlorate () industrial wastewater requires efficient removal to prevent adverse environmental impacts, however, high concentration and low biodegradability give rise to poor bioreduction performance. -autotrophic granular sludge (-AuGS) was firstly cultivated for high concentration perchlorate () removal in the upflow anaerobic sludge blanket (UASB) reactor (: 150 mg L−1). Simultaneously, the was utilized to control the generation as electron donor, the effluent concentration (190 mg L−1) was satisfied with drinking water standard (250 mg L−1). Under the optimized condition of hydraulic retention time (HRT) (6 h) and / molar ratio (2.2), more EPS was secreted, which promoted the -AuGS formation and stability. Though acclimation of 146 d, the -AuGS was formed with a large average granular sludge size (612 μm) and an excellent settleability (sludge volume index: SVI5/SVI30 = 1). With the mature -AuGS formation, the highest and loading was increased to 1.06 and 0.75 kg m−3 d−1. Interestingly, Georgfuchsia, Methyloversatilis, Sulfurisoma, and Exiguobacterium were the main microbial community in the -AuGS. This study proposed to form a novel -AuGS for developing the high concentration removal performance and to utilize the as an electron donor for controlling the excessive generation.