| Title |
The effect of PAC dosage on treatment efficiency of membrane - bioreactor for textile wastewater treatment |
| Authors |
황규대(Gye Dae Whang),임근택(Geun Tae Lim),박연종(Youn Jong Park) |
| Abstract |
The purpose of this study was to investigate the effect of PAC dose on treatment efficiency of membrane-bioreactor(Membrane-PACT) for dyeing wastewater treatment. Membrane-bioreactor process consisted of a suspended growth bioreactor and a tubular ceramic microfiltration unit. Powdered activated carbon was added into the bioreactor to maintain the concentration of 2,000㎎/L to evaluate the effectiveness and to find optimum dosage of carbon for removal of organic matter and coloring stuff. Activated sludge reactor(AS) and powdered activated carbon activated sludge reactor(PAC-AS) were operated as a control reactor to compare the treatment efficiency with membrane- bioreactor with activated carbon. Addition of PAC into the bioreactor does not affect the membrane flux significantly. Higher removal efficiency of soluble organic matter and coloring stuff was observed from membrane bioreactor with activated carbon and powdered activated carbon activated sludge reactor. It showed that the improvement of removal efficiency of organic matter was due to the elevation of biodegradability of microorganisms owing to PAC addition. However, the improvement of color removal efficiency was due to the adsorption of PAC. Membrane bioreactor with PAC showed higher soluble organic matter and color removal efficiency. At the beginning of operation, soluble organic matter and color removal efficiency was about 96% and 975 respectively. However, this high removal efficiency decreased to 77%, 56% respectively after 25days of operation due to the accumulation of organic matter and coloring stuff in bioreactor. Sludge withdrawing from Membrane-PACT process was found to enhance the color removal by adding virgin carbon and maintaining proper concentration of microorganisms. However, this operating strategy does not improve removal efficiency of soluble organic matter significantly. |