Review of Wastewater Treatment Methods and MBR Technology for Application in Biodiesel Plants

The objective of this paper is to critically review the significance of MBR technology for wastewater treatment derived Biodiesel plant with Alkali-Catalyzed Trans-esterification process. The whole study was carried out into two stages. In the first stage, pretreatment was studied with H2SO4 at the different pH range of 2.4 to 9 along with the removal efficiencies of BOD, COD and Oil & Greases. It was found that wastewater derived from Biodiesel Plant with Alkali Catalyzed Trans-esterification process contained a high pH, low nitrogen content and high hexane extracted oil which inhibited the growth of micro-organisms. Therefore, several nutrients such as nitrogen source (ammonium sulfate, ammonium chloride or urea), yeast extract, KH2PO4 and MgSO4.7H2O were studied to find out the favorable conditions for micro-organism growth in wastewater. The optimal C/N ratio was studied between 17 and 68 when using urea as a nitrogen source. In the second stage, submerged membrane bioreactor (MBR) was studied for the acidified waste water at different hydraulic retention times (HRTs) to find out the removal efficiencies of COD, BOD and Oil & Grease. Keyword: Submerged Membrane bioreactor (MBR); Biodiesel wastewater treatment; Microfiltration; Commercial application; Oil-rich phase