| dc.description.abstract | Abstract
In order to conform with the latest effluent ammonia nitrogen control limitation, Hsinchu Science park sewage treatment plant uses Membrane Bioreactor (MBR) as the key treatment process to enhance the function. The fouling resulted from water characteristics may influence the service life of membrane, so this study aims at the wastewater (sewage) of Hsinchu park sewage treatment plant, and discusses the potential factors in membrane fouling. The specific research content includes the quality of influent and effluent of the sewage treatment plant in last three years, analysis of wastewater characteristics; the model plant with the same process as the actual plant is used for experiment, the parameters are adjusted to understand the influence of different operation factors on membrane fouling.
The findings show that the influent and effluent quality data of sewage plant are used to calculate Langelier Saturation Index (LSI) and Ryznar Stability Index (RSI), the results show that the water is relatively corrosive and unlikely to scale. The transmembrane pressure (TMP) is inversely proportional to the membrane permeability, the higher the TMP is, the lower is the permeability. Different aeration rates influence the crossflow velocity, the permeability is better if the aeration rate is controlled at 40 LPM. If the sludge concentration is controlled at 4,000~8,000mg/L, it is favorable for MBR operation. When the membrane permeate flux is controlled at 2.15 LPM, the permeability is obviously better than 2.7 LPM and 3.2 LPM. The TMP increases faster as the permeate flux increases, the membrane fouling is accelerated. Three cycles of maintenance cleaning procedure with 0.2% HCl, 2 minutes′ agent feed and 8 minutes′ water feed have good effect; 16 hours′ maintenance cleaning procedure is preferred, which is likely to remove/retard membrane fouling. In addition, considering Hsinchu Science Park undertaking process variability, the water quality must be tested periodically, so as to master the water characteristics. According to the acid and alkali resistance of membrane, the membrane suitable for Hsinchu Science Park water characteristics is selected for operation, and it is suggested to periodically check whether the membrane appearance has filament break or wrapping after a period of operation, so as to guarantee the treated water quality.
Keywords: membrane bioreactor (MBR); fouling; membrane permeability; transmembrane pressure (TMP)
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