天然沸石与纳滤组合工艺处理铜突发污染的应用

纳滤工艺被广泛应用于分散式饮用水深度处理,能解决饮用水苦咸化,盐碱化或微污染等常规水处理工艺无法规避的用水风险,在长时间运行过程中还能有效应对重金属等突发污染风险。但重金属污染易加重纳滤膜污染,需要增设预处理装置加以缓冲,实现纳滤装置的长久稳定运行。而天然沸石具有良好的筛分性能和吸附性能,能够有效缓冲重金属对纳滤装置的冲击。试验以重金属铜为例,证明水中铜离子会造成纳滤不可逆污染比例增加,不利于系统稳定运行;天然沸石对铜离子有很好的吸附效果,静态吸附试验表明天然沸石对水中铜离子的最大吸附量为3.03 mg/g,通过正交试验合理设计吸附预处理,能够有效为纳滤工艺提供安全进水,保证纳滤进水铜离子浓度低于10 mg/L。实践工艺中,吸附预处理能有效缓解纳滤膜不可逆污染,而且吸附-纳滤组合工艺对铜离子及部分其他重金属离子表现出良好的处理效果。

Application of Combined Process of Natural Zeolite and Nanofiltration for Treatment of Emergency Copper Pollution

Nanofiltration(NF)is widely used in decentralized drinking water treatment,which can solve the water risk such as brackish water,salinization,or micro pollution of drinking water.NF can also effectively deal with emergency fouling risks such as heavy metals during long-term operations.However,NF membrane pollution is easily aggravated by heavy metal.It is necessary to add a pretreatment device to achieve long-term stable operation of NF.The natural zeolite has good adsorption properties,which can effectively buffer the impact of heavy metals on the NF.The experiment took heavy metal copper as an example to prove that copper ion in water could increase the irreversible membrane fouling of NF.Natural zeolite had a good adsorption effect on the copper ion.The static adsorption experiment showed that the maximum adsorption capacity of natural zeolite for the copper ion in water is 3.03 mg/g.Through the orthogonal test,the adsorption pretreatment could ensure that the concentration of the copper ion in the influent of NF was less than10 mg/L.In the practical process,the adsorption pretreatment could effectively alleviate the irreversible fouling of the NF membrane,and the combined adsorption-NF process showed a good treatment effect on the emergency pollution of the copper and some other heavy metal ions.