An Integrated System of UASB-DHS-A₂SBR for Effective Removal of Organic Matter and Nutrients from Municipal Wastewater

Abstract

In order to fulfill the imperative need of proper organic matter and nutrient removal technology, an integrated system of up-flow anaerobic sludge blanket (UASB), down-flow hanging sponge (DHS) and anaerobic/anoxic sequencing batch reactor (A₂SBR) is developed in this study. An aerobic reactor called DHS has porous sponge material for oxygen supply and microbes retention. Likewise, A₂SBR is reported to remove nutrients, like phosphorus and nitrogen, effectively using denitrifying phosphorus accumulating organisms (DNPAOs) with less sludge production. The findings of this study demonstrated that the average SS, COD and BOD removal efficiencies by UASB-DHS were 86%, 87% and 97%, respectively, in summer and were 69%, 78% and 88%, respectively, in winter. Moreover, upon adjusting the pH to 7.4 ± 0.2 and with COD/P of 20, phosphate removals as low as 1 mg-P/L and nitrate concentration as low as 5 mg-N/L were achieved. Therefore, this proposed system could be an innovative solution for the present prevalent municipal wastewater treatment problems due to its effective organic and nutrient removal capabilities.