Enhanced reduction of excess sludge and nutrient removal in a pilot-scale A2O-MBR-TAD system

Abstract

In this study, a pilot scale anaerobic-anoxic-oxic (A2O) process with submerged membrane (MBR) in the oxic tank was coupled with thermophilic aerobic digestion (TAD) reactor and was operated for longer than 600 days to treat real domestic wastewater. Regardless of the varying conditions of the system, the A2O-MBR-TAD process removed MLSS, TCOD, BOD, TN, TP, and E. coli about 99%, 96%, 96%, 70%, 83%, and 99%, respectively. The additional TP removal of the system was due to the precipitating agent directly added in the oxic reactor, without which TP removal was about 56%. In the TAD reactor, receiving MLSS from the oxic tank (MBR), about 25% of TSS and VSS were solubilized during 2 days of retention. The effluent of the TAD reactor was recycled into the anoxic tank of A2O-MBR to provide organic carbon for denitrification and cryptic growth. By controlling the flowrate of wasting stream from the MBR, sludge production decreased to almost zero. From these results, it was concluded that the A2O-MBR-TAD process could be a reliable option for excellent effluent quality and near zero-sludge production.

Effects of Organic-Loading-Rate Reduction on Sludge Biomass and Microbial Community in a Deteriorated Pilot-Scale Membrane Bioreactor

“…So far, chemical and thermal treatments have been applied to reduce excess sludge biomass during the operation of MBRs (8, 23). We very recently reported that a decrease in the feed to microorganism ratio during a simulated rainfall condition suppressed an increase in the sludge biomass in the MBR (20).…”

Challenges and Emerging Trends in Advanced Oxidation Technologies and Integration of Advanced Oxidation Processes with Biological Processes for Wastewater Treatment

“…Ventura et al ( 2011) [78] treated real domestic wastewater with a pilot-scale anaerobicanoxic-oxic process, with a submerged membrane in the oxic tank and a thermophilic aerobic digestion reactor. The removal of MLSS, TCOD, BOD, TN, TP, and E. coli by the A 2 O-MBR-TAD process was reported to be nearly 99%, 96%, 70%, 83%, and 99%, respectively.…”