Anaerobic granule sludge formation and perchlorate reduction in an upflow anaerobic sludge blanket (UASB) reactor

It is a novel biological method to reduce high concentration of perchlorate using an upflow anaerobic sludge blanket reactor with perchlorate granular sludge. A high perchlorate loading rate of 9.96 g/(L·d) was achieved in the UASB reactor with the perchlorate reduction rate of 84.7%. The perchlorate granular sludge wet density, mechanical strength and VSS/SS of the mature perchlorate granular sludge were 1.2516 g/cm3, 97.18% and 0.45, respectively. 16S rDNA gene amplicon sequencing indicated that the first abundant bacteria among all of the detected bacteria were Sulfurovum, Methyloversatilis and Sulfurospirillum for floccular anaerobic sludge, denitrifying granular sludge and perchlorate reduction granular sludge, respectively. The perchlorate reduction rate was compared with prediction of the first-order substrate removal models, second-order substrate removal models and the Stover-Kincannon substrate removal models with the correlation coefficient 0.9300, 0.9988 and 0.9995, respectively. These models may be used in predicting the behavior or design of the perchlorate reduction.