Guo Xiaoyan, Chen Xi, Hu Wanli
Key Laboratory of Pollution Processes and Environmental Criteria, Nankai University, China.
Environ Technol. 2009 Apr 14;30(5):431-5. doi: 10.1080/09593330902757454.
Hydrophilic natural organic matter, which is primarily composed of polysaccharide-like substances, has been found by some researchers to be the main foulant in ultrafiltration surface water. Sodium alginate, one kind of polysaccharide, was selected as model hydrophilic natural organic matter to investigate the fouling characteristics of a (polyvinylchloride) ultrafiltration membrane and the efficiency of cleaning the membrane fouled with sodium alginate. The permeate flux profile and the slight decrease in sodium alginate rejection resulted from the concentration polarization. Hydraulic flushing and chemical cleaning methods, under different cleaning conditions, were used separately to clean the fouled membrane. The results showed that most of the sodium alginate on the polyvinylchloride membrane can be removed by physical cleaning, which indicated that the fouling was highly reversible. Three chemical cleaning operating parameters, i.e. NaOH concentration, temperature and cleaning time, had significant influences on cleaning efficiency. During chemical cleaning, the flux recovery rates were over 100%, which were assumed to be the results of membrane surface modification caused by NaOH cleaning.
亲水性天然有机物主要由类多糖物质组成，一些研究人员发现它是超滤地表水时的主要污染物。海藻酸钠作为一种多糖，被选为亲水性天然有机物模型，用于研究（聚氯乙烯）超滤膜的污染特性以及清洗被海藻酸钠污染的膜的效率。渗透通量曲线以及海藻酸钠截留率的轻微下降是由浓差极化导致的。在不同清洗条件下，分别采用水力冲洗和化学清洗方法来清洗被污染的膜。结果表明，聚氯乙烯膜上的大部分海藻酸钠可通过物理清洗去除，这表明污染具有高度可逆性。三个化学清洗操作参数，即氢氧化钠浓度、温度和清洗时间，对清洗效率有显著影响。在化学清洗过程中，通量恢复率超过100%，这被认为是氢氧化钠清洗导致膜表面改性的结果。
