Keywords: biofilm, biological treatment, chemical oxygen demand, COD, membrane bioreactors, MBR, membrane fouling, oily wastewater, rotating biological contractor, RBC, total petroleum hydrocarbon, TPH, wastewater treatment
Oily wastewater treatment using membrane bioreactor
A novel implementation of a membrane bioreactor (MBR) has been studied in this paper. It is utilised as combination of rotating biological contractor (RBC) and an external membrane for oily wastewater treatment. The performance of MBR was compared with the standalone RBC. The RBC used in this investigation is the same one combined with the membrane to form the MBR. Wastewater biodegradability has been evaluated by two factors: chemical oxygen demand (COD) and total petroleum hydrocarbon (TPH). They are both compared together for different hydraulic retention times (HRTs) and petroleum pollution concentrations in RBC and MBR. The ratio of TPH to COD of molasses has been varied between 0.2 to 0.8 at two HRTs of 18 and 24 h while the temperature, pH and dissolved oxygen were kept in the range of 20–25°C, 6.5–7.5, and 2–3.5 mg/L, respectively. Optimal TPH removal efficiency (99%) observed at TPH/COD = 0.6 and HRT = 24 h in MBR. The experimental results showed that MBR had higher treatment efficiency than RBC at all ratios and HRTs.