Development of integrated membrane bioreactor for industrial wastewater treatment and reuse

Abstract

The dissertation entitled Development of Integrated Membrane Bioreactor for Industrial Wastewater Treatment and Reuse was based on wastewater treatment by integrated membrane bioreactor to meet the stringent limits. The versatility of integrated membrane bioreactor is single foot print with less energy consumption and fouling. The pretreatments employed with MBR were Electrooxidation, Ozonation, Adsorption and Biofilm carriers in Activated Sludge Process. In this research work, we have used pharmaceutical wastewater for treatment and analyzed for various parameters such as Chemical Oxygen Demand(COD), Biological Oxygen Demand (BOD),Total Organic Carbon ( TOC), Total Suspended Solids( TSS)and Total Dissolved Solids (TDS). Electrooxidation Integrated Membrane Bioreactor (IMBR) in batch mode was carried out in real pharmaceutical wastewater and analyzed for water quality by its eminent effluent parameters. The optimal EO was first determined with the CDs range from 0.433 mA/cm2 - 0.769 mA/cm2 . Scanning Electron Micrographs (SEM) of IMBR showed less void volume and pore constriction compared with that of the MBR. The results demonstrated that electro-oxidation at 0.748 mA/cm2 was suitable for long-time operation of IMBR. The removal of total organic compound and chemical oxygen demand were observed to be greater than 90% and that of the total dissolved solids were above 60% under constant pressure of 400 kPa. The increase in permeate flux was found 45 % as compared to MBR. The fouling mechanism was verified using Hermia models and the results exhibited a standard error of 0.0046 which in turn evince less internal fouling which was in agreement with the SEM images. The most striking observations made in this study were the efficacy of IMBR to operate without the problem of filamentous bulking and the results implied that electro-oxidation might be the key factor for the success of fouling mitigation in IMBR. In order to enhance the performance of integrated membrane bioreactor, adsorptive cake, bio-film carriers and ozonation as pretreatments referred to be Integrated Moving Bed Membrane Bioreactor (IMBBR). The optimal Current Density (CD), Hydraulic Retention Time (HRT), adsorptive cake dosage and ozone dosage were maintained as 0.588A/cm2 , six hours, 25.83g and 2-5 Lmin-1 . Scanning electron micrographs of IMBBR, adsorptive cake and biofilm carriers showed less void volume, pore constriction and reduction in organic and inorganic pollutants. The total organic compound, chemical oxygen demand and total dissolved solids removal were observed to be greater than 95%, 95 % and 70% under a constant pressure of 300 kPa with the flux increase of 35%. The model was developed using resistance in series model which proved less internal fouling which was in agreement with the SEM and LCMS images and the same has been by Hermia models. The observations from the study showed less energy consumption as compared to IMBR and MBR without the problem of filamentous bulking. The results implied that all the physiochemical properties might be the key component for the success of fouling mitigation in IMBBR newline