连续过滤-超滤工艺处理松花江水中试研究

A pilot study of continuous filtration-ultrafiltration process for Songhua River water treatment

摘要:

为探究以超滤为核心的短流程、低药剂的绿色净水工艺可行性,以连续过滤作为膜前预处理工艺,通过中试实验考察连续过滤-超滤工艺处理松花江水的处理效能和膜污染特性,并与直接超滤进行对比实验,考察连续过滤预处理在组合工艺中的作用.结果表明,连续过滤-超滤工艺对松花江水的浊度和氨氮均有良好的去除效果,去除率分别为99.75%和70.77%,但对有机物的去除效果较差,COD_Mn和UV₂₅₄的去除率分别为32.21%和17.12%.超滤膜前期污染较缓慢,15 d后污染速率加快,在第50天跨膜压差增长至50.3 kPa,达到膜污染上限.连续过滤对色氨酸类蛋白质有较好的去除效果,而超滤对溶解性生物代谢物、色氨酸类蛋白质、富里酸类有机物和腐殖酸类有机物均有一定的截留作用,其中腐殖酸类有机物和色氨酸类蛋白质是超滤膜的主要不可逆污染物.组合工艺对COD_Mn、UV₂₅₄和氨氮的去除率比直接过滤分别高出9.97%,7.02%和33.84%,且膜污染速率远低于直接超滤.研究成果将推动超滤膜技术在微污染源水净化方面的广泛应用.

Abstract:

To explore the feasibility of the green water purification process of ultrafiltration with short process and low chemical dosage, continuous filtration was used as the pretreatment process, and a pilot study of continuous filtration-ultrafiltration process for Songhua River water treatment was performed in terms of treatment efficiency and membrane fouling. In addition, a comparison experiment with direct ultrafiltration was performed to investigate the role of continuous filtration in the combination process. The results showed that the continuous filtration-ultrafiltration process had excellent removal efficiency for turbidity and ammonia nitrogen. The removal rates were 99.75% and 70.77%, respectively. But the removal of organic matter was inefficient. The removal rates of COD_Mn and UV₂₅₄ were 32.21% and 17.12%, respectively. In the early stage, the rate of membrane fouling was slow, and it became faster after the 15th day. The transmembrane pressure increased to the superior limit of 50.3 kPa on the 50th day. Continuous filtration showed a good removal effect on tryptophan protein, and ultrafiltration showed different degrees of removal of soluble biometabolites, tryptophan proteins, fulvic acid organics, and humic acids. Humic acids and tryptophan proteins were the main irreversible contaminants of ultrafiltration membranes. The removal rate of COD_Mn, UV₂₅₄, and ammonia nitrogen by the combination process were 9.97%, 7.02%, and 33.84% higher than that of direct filtration, respectively. Moreover, the membrane fouling rate of the combination process was much less than that of direct ultrafiltration. Continuous filtration pretreatment cannot only improve the removal efficiency of organic matter and ammonia nitrogen, but also alleviate ultrafiltration membrane fouling effectively.