Comparative study of submerged membrane bioreactor and extended aeration process coupled with tubesettler for hospital wastewater treatment

Abstract

There are a number of wastewater studies, however research work of hospital wastewater is still lacking. This is owing to low volume of wastewater as compared to municipal wastewater. Nevertheless, hospital wastewater is very distinct in nature as compared to wastewater of other origins particularly owing to various hospital related activities. Hence this study evaluated treatment performance of hospital wastewater using Submerged Membrane bioreactor (SMBR) and Extended aeration process. The investigation parameters for both treatment process was kept same for comparison of treatment efficiency of both processes. Additionally, Tubesettler was employed to enhance treatment efficiency. The treatment efficiency of both processes was low. However, encoupled with Tubesettler satisfactory results were obtained. The BOD5/COD ratio for SMBR effluent varied between 0.22 and 0.92 while for extended aeration process ratio ranged between 0.29 and 0.92. The increase in nitrate concentration in SMBR and EA indicated nitrification. But since the system was well aerated and no anoxic or anaerobic condition prevailed denitrification was not observed. The results of this study suggested that using hospital wastewater as seeding and as influent provided lesser efficiency as compared to synthetic wastewater as influent. Also 85% COD reduction and 91% BOD5 removal in EA indicated better performance as compared to SMBR with 72% COD reduction and 78% BOD5 removal. However, for nitrification SMBR (295%) performed better than EA (140%) Future studies are required to establish conventional parameters with pharmaceutical removal, variation of control parameters on treatment efficiency and effect on microbial activities.