热电厂废弃反渗透膜清洗研究

Research on the cleaning of waste reverse osmosis membrane in thermal power plant

为了对废膜元件进行循环利用,降低其跨膜压差,文章采用不同的清洗剂,配合不同的清洗方法对热电厂替换下的废弃反渗透膜元件进行了清洗实验研究.结果表明:以0.1%NaOH溶液+0.25%SDS-Na以及0.2%HCl溶液依次对废膜进行清洗,并采用正洗和反洗相结合的清洗方法,能够有效降低废膜的跨膜压差.此外,用0.1%NaOH溶液辅以压缩空气进行气液两相清洗能够进一步降低废膜的跨膜压差至与同型号新膜相同.经过清洗之后,废膜元件产水量约为新膜的2.4倍,脱盐率为97.3%,可在低能耗、高通量、低脱盐率要求的场景中循环使用.

In order to recycle the waste membrane element and reduce the pressure difference,this paper used different cleaning agents and different cleaning methods to carry out cleaning experiments on the waste reverse osmosis membrane element replaced by the thermal power plant.The results showed that the waste membrane was washed sequentially with 0.1%NaOH solution+0.25%SDS-Na and 0.2%HCl solution,and a cleaning method combining forward washing and back washing was used to effectively reduce the transmembrane pressure difference of the waste membrane.In addition,using 0.1%NaOH solution supplemented with compressed air for gas-liquid two-phase cleaning can further reduce the transmembrane pressure difference of the waste membrane to the same as the new membrane of the same model.After cleaning,the water output of the waste membrane element is about 2.4 times that of the new membrane,and the salt rejection rate is 97.3%.It can be recycled in scenarios that require low energy consumption,high throughput,and low salt rejection.