Enhancement of aerobic granular sludge by high-frequency alternating OLR
LI Dong1, GAO Fei-yan1, XIE Yi-bo1, LI Zhu1, ZHANG Jie1,2
1. Key Laboratory of Beijing Water Quality Science and Water Environment Recovery Engineering, Beijing University of Technology, Beijing 100124, China; 2. State Key Laboratory of Urban Water Resource and Environment, Harbin Institute of Technology, Harbin 150090, China
Abstract:In this study, four parallel cylindrical sequencing batch reactors, R1, R2, R3 and R4, were operated by constant organic loading rate (OLR) and three alternating OLR modes respectively, fed with synthetic water. Their high and low OLR were 0.67/0.67, 0.71/0.60, 0.77/0.52 and 0.80/0.40gCOD/(L∙d) respectively. The effect of high-frequency alternating OLR on the performance of aerobic granular sludge was explored to provide feasible strategies for improving the stability of aerobic granular sludge. The results showed, the integrity coefficients of R1, R2, R3 and R4 could reach 87.26%, 94.78%, 96.29% and 79.63%, respectively. The EPS content (VSS) of the four reactors were 81.04, 109.46, 115.28 and 139.56mg/g and PN/PS were 4.75, 7.49, 8.28 and 3.26, respectively, indicating that the m value (high OLR/low OLR) of 1.48 was beneficial to improve the structural stability of aerobic granular sludge. In addition, the average COD removal efficiency of R1, R2, R3 and R4in the stable period were 92.58%, 91.52%, 92.45% and 92.52%, respectively. The average TP removal efficiency were 92.81%, 93.35%, 95.10% and 61.01%, respectively. The average TN removal efficiency were 93.04%, 92.24%, 92.06% and 85.32%, respectively, indicating that the aerobic granular sludge had the best effect of removing pollutants when the m value was 1.48.
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