Intermittent cycle extended aeration system pilot scale (ICEAS-PS) for wastewater treatment: experimental results and process simulation

Abstract

Intermittent cycle extended aeration system is a modification of a conventional sequencing batch reactor system in which the system is operated under continuous feed. The objective of this research is to study the effect of sludge retention time and aeration pattern on the performance of intermittent cycle extended aeration system pilot scale for wastewater treatment. In addition, the process simulation using GPS-X software was conducted. Five different runs of sludge retention times of 10, 15, 20, 25 and 30 days were studied. The optimum sludge retention time for wastewater treatment by intermittent cycle extended aeration system pilot scale was 10 days, and under operating condition of sludge retention time of 10 days, effluent quality was 15.5 ± 3.8, 6.5 ± 1.1, 5.3 ± 1.6, 0.7 ± 0.2, 5.0 ± 1.4 mg/L and 1.4 ± 0.7 mg/L for COD, BOD5, TSS, NH4–N, TN and TP which amply met the local regulation of class A treated wastewater. GPS-X sensitivity analysis tool box was used to determine the most sensitive kinetic parameters affecting the intermittent cycle extended aeration system pilot scale performance. Out of about 50 kinetic parameters, YH, bH, μA, Ko, bA, Ka and μPAO appeared to the most sensitive kinetic parameters. The calibrated GPS-X model proved that the presence of anoxic phase in the cycle has a significant impact on nitrogen and phosphorus removal. In addition, intermittent aeration pattern achieved the highest performance compared with other patterns of aeration only, aeration/anoxic and anoxic/aeration.