生物粉末活性炭/超滤组合工艺处理微污染原水

针对微污染原水中存在的有机物和氨氮等污染物,采用生物粉末活性炭/超滤(BPAC/UF)组合工艺进行处理。结果表明,当进水氨氮浓度较低时,硝化细菌活性较差,无法充分发挥生物降解作用,氨氮去除率较低,同时有机物去除率也较低;当进水氨氮浓度在0. 6 mg/L左右时,可以形成稳定的生物活性炭,组合工艺对氨氮的去除率较高,且对有机物的去除率较为稳定。进水中主要以分子质量<5 ku的有机物为主,组合工艺对这部分有机物的去除率也最高。组合工艺对疏水性物质的去除,主要依靠生物粉末活性炭的吸附降解和膜面滤饼层的截留作用。NaClO强化反冲洗可以很好地降低跨膜压差的增长速度,当NaClO浓度为400 mg/L、反冲洗时间为10min时可达到最佳清洗效果。

Treatment of Micro-polluted Raw Water by Combined Process of Biological Powdered Activated Carbon and Ultrafiltration

A combined process of biological powdered activated carbon and ultrafiltration(BPAC/UF)was used to removal organic matter and ammonia nitrogen in micro-polluted raw water.When the influent ammonia nitrogen concentration was low,the activity of nitrifying bacteria was poor and it could not fully play the role of biodegradation,leading to low removal rates of ammonia nitrogen and organic matter.When the influent ammonia nitrogen concentration was about 0.6 mg/L,the stable biological activated carbon could be formed,the removal rate of ammonia nitrogen by the combined process was high,and the removal rate of organic matter was stable.The influent mainly consisted of organic matter with molecular weight of less than 5 ku,and the combined process had the highest removal rate of organic matter with molecular weight of less than 5 ku.The removal of hydrophobic substances by the BPAC/UF combined process mainly depended on the adsorption and degradation of the biological powdered activated carbon and the interception of the membrane fouling cake layer.The NaClO enhanced backwashing could reduce the growth rate of transmembrane pressure satisfactorily,and the best cleaning effect could be achieved when the concentration of NaClO was 400 mg/L and the backwashing time was 10 min.