title: Biodegradability of oily wastewater using rotating biological contactor combined with an external membrane.
abstract: BACKGROUND
  A novel implementation of a hybrid membrane bioreactor (HMBR) has been studied in this paper. It is utilized as combination of rotating biological contractor (RBC) and an external membrane, as a new biological system for oily wastewater treatment.
  
  
  METHODS
  Chemical oxygen demand (COD) and total petroleum hydrocarbon (TPH) as factors of Biodegradability has been evaluated. They are both compared together for different hydraulic retention times (HRTs) and petroleum pollution concentrations in RBC and HMBR. The ratio of TPH to COD of Molasses has been varied between 0.2 to 0.8 at two HRTs of 18 and 24 hours 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.
  
  
  RESULTS
  The best TPH removal efficiency (99%) was observed in TPH/COD = 0.6 and HRT = 24 hr in HMBR and Removal efficiency was decreased in the ratios above 0.6 in both bioreactors.
  
  
  CONCLUSIONS
  The experimental results showed that HMBR had higher treatment efficiency than RBC at all ratios and HRTs.
authors.affiliation: Chemical and petroleum engineering department, Sharif University of Technology, Azadi St, Tehran, Iran.
authors.forename: Mahdieh
authors.initials: M
authors.lastname: Safa
authors.affiliation: Chemical and petroleum engineering department, Sharif University of Technology, Azadi St, Tehran, Iran.
authors.forename: Iran
authors.initials: I
authors.lastname: Alemzadeh
authors.affiliation: Chemical and petroleum engineering department, Sharif University of Technology, Azadi St, Tehran, Iran.
authors.forename: Manouchehr
authors.initials: M
authors.lastname: Vossoughi
keywords: Biological treatment; Hybrid membrane bioreactor; Oily wastewater; Rotating biological contractor