| This study develops, evaluates, and optimizes the potential of a novel “counter-diffusional” membrane biofilm reactor system to biologically treat and remove trichloroethylene (TCE) from contaminated soil and groundwater caused by industrial activities. TCE, as a very popular industrial solvent, has been widely used for degreasing in aircraft engines, electronic components industry, automobile parts, printing industry, and textiles industry for about 55 years. Because of widespread industrial use, inadequate disposal techniques, and accidental spills, TCE has become a crucial contaminant in soil and groundwater. Because of its toxicity and carcinogenic, TCE has been classified and rated as a priority hazardous waste pollutant by the US-EPA.; In this research a novel and potentially important methanotrophic biofilm design and operational factors for overcoming some key problems inherent in cometabolic biodegradation of CAHs were studied. The objectives of the research are to investigate and evaluate design and operational factors affecting the sustainability and degradation rates of TCE transformation in a counter-diffusional membrane-attached methanotrophic biofilms.; As a first step attaining this objective, an overall mass transfer coefficient of the bioreactor was developed, a 23 laboratory experimental design have already conducted, and the development of a mathematical model and computer simulation describing the concentration profile of substrates and TCE within the biofilm has been introduced. The model primarily focuses on concentration profiles of CH4, O2, and TCE to find potential for process optimizations.; A maximum sustainable TCE removal flux of approximately 205 μmol/m 2/day was successfully attained when the CH4 utilization rate was approximately 11.667 mmoles/m2/hr, the TCE loading rate was approximately 400 μmol/m2/day. The experimental results also demonstrated that higher biofilm detachment rate of 32.4 mg/L.; Normal probability plot and pareto chart indicated that methane partial pressure (P) and hydraulic Reynolds's numbers (Re) have important and significant positive effects on the TCE degradation rates. The average percentage of TCE removal efficiency falls between 78.6 and 94.7%. The calculated CH4 utilization rates falls between 7.919 and 11.667 mmoles/m2 /hr. The biofilm detachment rates falls between 12.1 and 32.7 mg/L of measured Total Suspended Solids (TSS) in the bioreactor's effluents. |
