Profitable sludge management via novel combined ozone disperser pretreatment coupled with membrane bioreactor for treating confectionary wastewater

In this study, two lab scale membrane bioreactor (MBR) with working volume of 12 L were used to study the effect of sludge pretreatment over period of 120 d. Among the two MBRs one was used as a control (U-MBR) and another one was used as experimental (P-MBR). After attaining stable operation, 540 mL/d of mixed liquor was withdrawn and subjected to Ozone Disperser Pretreatment (ODP). ODP results with 22% of Chemical Oxygen Demand (COD) solubilisation and 19% of solids reduction. Upon recycling ODP sludge, 36% of sludge reduction was achieved in P-MBR, when compared to U-MBR. The yield observed of P-MBR (0.165 g SS/g COD) is lower than U-MBR (0.254 g SS/g COD). The effluent organic concentration of both MBRs is in the range of 6–12 mg/L COD. Incorporation of ODP in P-MBR, reduces the cost to manage sludge for treating 1 m³ of wastewater from −0.0334 to −0.0276 USD.