混凝-膜分离集成工艺处理表面活性剂废水的研究

Study on Treatment of Surfactant Wastewater by Coagulation and Membrane Separation Integrated Process

废水中的表面活性剂成分复杂、分子量小,若不经处理直接排入水体,将造成水体的富营养化。膜分离法处理废水存在膜易污染、清洗困难的问题。针对上述问题,文章提出采用混凝-膜分离集成工艺处理表面活性剂废水。首先,采用相转化法自制二氧化钛改性聚偏氟乙烯超滤膜,并通过扫描电子显微镜、傅里叶红外光谱、接触角测量仪测试膜的结构和性能;然后以十二烷基苯磺酸钠配制表面活性剂废水,以聚合氯化铝作为混凝剂,研究紫外光照强度、进水流量,溶液p H值对集成工艺处理效果的影响。研究结果表明,改性膜表面具有致密分离层,断面呈指状孔和海绵状结构;傅里叶红外光谱表明聚乙二醇和二氧化钛的加入掩盖了部分聚偏氟乙烯晶型的红外吸收;二氧化钛改性膜具有更小的接触角;紫外光照强度和进水流量对混凝-膜分离工艺影响较小,溶液酸碱性对工艺影响较大,并且当溶液p H值为4.5时集成工艺对表面活性剂废水处理效果最佳。混凝-膜分离集成工艺作为一种新型解决方案,在大规模、高效、低成本处理生活和工业废水中有望发挥重要作用。

Surfactants have complex compositions and low molecular weights, which usually leads to the eutrophication of waterbodies. For the treatment of wastewater that contains surfactants, the membrane separation technology is usually adopted. However, the membrane is easily polluted and the cleaning process is usually laborious. In this work, a new surfactants wastewater processing technology was investigated by combining the coagulation and membrane separation techniques. Firstly, the phase inversion technique was used for the preparation of titanium dioxide modifi ed polyvinylidene fl uoride ultrafi ltration membrane. Structure and properties of the membrane are tested by several instrumentations, like the scanning electron microscopy, fourier transform infrared spectroscopy, and contact angle instrument. Secondly, using sodium dodecyl benzene sulfonate solution and polymerization aluminum chloride as surfactant wastewater and coagulant respectively, the treatment effect is evaluated with respect to ultraviolet light intensity, water fl ow rate and p H values. By observation, the modified membrane has dense-selective layer on the surface, and its cross-section is composed with finger holes and spongy structures. By the analysis of fourier transform infrared spectroscopy, polyethylene glycol and titanium dioxide in the modifi ed membrane can cover apart of infrared absorption of polyvinylidene fl uoride. The modifi ed membrane has relative small contact angle and its performance is also insensitive to the change of ultraviolet light intensity and water fl ow rate. Moreover, the process can reach best performance while the wastewater with p H value of 4.5. The proposed surfactants wastewater process technique has distinct advantages of high effi ciency and low-cost, which makes it with great potentials in the application of large scale industrial and domestic wastewater processing.