Efficiency and kinetics in treatment of wastewater from garages and residential oil spills using membrane bioreactor technology

This research focused on the biodegradation of petrogenic hydrocarbons in wastewater using membrane bioreactor technology. Industrial oily wastewater with mixed fractions of hydrocarbons was collected and continuously treated for 50 days. Membrane bioreactor (MBR) effluent samples were analyzed daily for both aliphatic and aromatic hydrocarbons using gas chromatography–mass spectrometry. Many other water quality parameters were also measured including chemical oxygen demand, dissolved oxygen, turbidity, heavy metals and heterotrophic bacterial counts. These parameters were essential in evaluating the performance of the MBR treatment process. During the treatment period, 98.0, 96.0 and 99.8 % removal of total aliphatic hydrocarbons in the lube oil fraction, total aliphatic hydrocarbons and total polycyclic aromatic hydrocarbons, respectively, were achieved. Overall, total organic removal, measured in terms of chemical oxygen demand, ranged from 88.3 to 92.6 %. Degradation kinetics was investigated for hydrocarbons and chemical oxygen demand. Half-lives of alkanes varied from several days to 40 days in the treatment process. Therefore, this study demonstrated that MBR is an effective treatment method for the removal of petroleum hydrocarbons in wastewater.

Keywords
Half-life; Alkanes; Polycyclic aromatic; hydrocarbons; Effluent; Petroleum; Biodegradation