1 School of Environmental and Municipal Engineering, Tianjin Key Laboratory of Aquatic Science and Technology, Tianjin Chengjian University, Jinjing Road 26, Tianjin 300384, China.
2 Department of Building, Civil, and Environmental Engineering, Concordia University, 1455 de Maisonneuve Blvd. W. Montreal, Quebec, Canada.

Perchlorate (ClO₄^-) industrial wastewater requires ef?cient removal to prevent adverse environmental impacts, however, high concentration and low biodegradability give rise to poor ClO₄^- bioreduction performance. S^2--autotrophic granular sludge (S^2--AuGS) was firstly cultivated for high concentration perchlorate (ClO₄^-) removal in the Upflow Anaerobic Sludge Blanket (UASB) reactor (ClO₄^-: 150 mg·L^-1). Simultaneously, the S^2- was utilized to control the SO₄^2- generation as electron donor, the effluent SO₄^2- concentration (190 mg·L^-1) was satisfied with drinking water standard (250 mg·L^-1). Under the optimized condition of HRT (6 h) and S^2-/ClO₄^- molar ratio (2.2), more EPS was secreted, which promoted the S^2--AuGS formation and stability. Though acclimation of 146 d, the S^2--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 S^2--AuGS formation, the highest ClO₄^- and S^2- 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 S^2--AuGS. This study proposed to form a novel S^2--AuGS for developing the high ClO₄^- concentration removal performance and to utilize the S^2- as electron donor for controlling the excessive SO₄^2- generation.