Computer-Aided Design and Simulation of a Membrane Bioreactor for Produced Water Treatment

Abstract

Membrane Bio Reactor (MBR) has been designed and simulation for the treatment of Chemical Oxygen Demand (COD), Total Suspended Solids (TSS), Total Organic Carbon (TOC), Total Dissolved Solid (TDS) and Oil/ Grease in produced water at a capacity of 54.1778 kg/hr for removal of 95%-99% contaminants. The MBR design equations were developed using the law of conservation of mass to determine the dimensions and functional parameters. The developed performance equations were integrated numerically using fourth-order Runge-Kutta embedded in MATLAB computer program to determine the optimum range of values of the reactor functional dimensions and functional parameters. The effect of rate of energy supply per reactor volume and substrate specific rate constant on the capacity of the membrane bioreactor were investigated. Also, the effect of initial loading of substrate on Solid Retention Time (SRT) was also investigated. Results showed that kinetic parameters influenced the percentage removal of contaminants as Hydraulic Retention Time (HRT) and size of MBR decreased with increase in specific rate constant at fixed conversion of contaminants. Also, HRT and MBR size increased as the conversion of Chemical Oxygen Demand (COD) was increased, while increased in the ratio of energy supplied per volume resulted in decreased of MBR volume. The effect of initial loading of substrate on SRT showed that increased in substrate loading increased the retention time of the solid at fixed substrate conversion, while the conversion of substrate to microorganism increased as the solid retention time was increased. The increased in initial loading of substrate concentration increased the production of Mixed Liquor Suspended Solids (MLSS). Thus, the size of MBR required for the conversion of the investigated contaminants at the design percentage removal increased in the following order: oil/grease < TSS < TOC < TDS. The MBR volume, height and HRT were 1.10 and 5.

Membrane Bioreactors for Produced Water Treatment: A Mini-Review

“…Optimum range of values of the functional dimensions and designed parameters of a submerged CSTR MBR was obtained by simulating the MBR’s performance on COD, TSS, TOC, TDS, and oil and grease removal [ 131 ]. The performance equations based on the law of conservation of mass were developed with assumptions such as constant flowrate, no concentration gradient, no contaminant diffusion/dispersion and operation under isothermal, isobaric, and steady state conditions.…”

“…The performance equations based on the law of conservation of mass were developed with assumptions such as constant flowrate, no concentration gradient, no contaminant diffusion/dispersion and operation under isothermal, isobaric, and steady state conditions. From Dagde et al’s [ 131 ] model, different volume, height, and hydraulic retention time are required to obtain 95% and 99% conversion with an SRT of 82.7 days. The fundamental fact therefore, still remains that the MBR plant is more complicated in both design and operation and there is greater risk of failure [ 132 ].…”