As an important water resource, brackish water has been extensively utilized in the industry. However, there are few cases of municipal potable water treatment plants that use low chloride content brackish water as the source. In this paper, the brackish water treatment efficiency of ultrafiltration (UF)/nanofiltration (NF) dual-membrane process was evaluated in a municipal potable water treatment plant, combining with a pilot optimization experiment. Results showed that UF guaranteed the inlet water quality of NF and NF could efficiently reject organics and salts, with a chloride removal over 95 %. Pilot experiment showed that the UF membrane flux decreased only 12 % after continuously 30-days operation under the optimized UF operation conditions, effectively extending the chemical cleaning interval. Response surface method was adopted in the NF removal efficiency and energy consumption optimization. With the increase of feed water conductivity, the influences of pressure and recovery on the removal efficiency were strengthened, and the removal efficiency could be regulated over a wider range. When the conductivity was less than 3500 μS/cm, NF could perform high treatment efficiency under the operation pressure of 0.65−0.85 MPa and recovery of 55–70 % . Besides, as feed conductivity increased, it was necessary to increase the pressure and reduce the recovery within this range to maintain efficient operation. This paper will provide a guidance for the UF/NF dual-membrane process design and operational optimization.

作为重要的水资源，苦咸水已在工业中得到广泛利用。但是，很少有使用低氯含量的微咸水作为水源的市政饮用水处理厂。本文在市政饮用水处理厂中，结合试点优化实验，评估了超滤（UF）/纳滤（NF）双膜工艺的微咸水处理效率。结果表明，超滤保证了NF的进水水质，并且NF可以有效地去除有机物和盐分，其中氯的去除率超过95％。中试实验表明，在优化的超滤运行条件下，连续运行30天后，超滤膜通量仅降低了12％，有效延长了化学清洗的间隔时间。响应面法被用于NF去除效率和能耗优化。随着给水电导率的提高，压力和回收率对去除效率的影响增强，去除效率可在较宽的范围内调节。当电导率小于3500μS/ cm时，NF在0.65-0.85 MPa的工作压力和55-70％的回收率下可以达到较高的处理效率。此外，随着进料电导率的增加，有必要在该范围内增加压力并降低回收率以维持有效的操作。本文将为UF / NF双膜工艺设计和操作优化提供指导。压力和回收率对去除效率的影响得到加强，可以在更大范围内调节去除效率。当电导率小于3500μS/ cm时，NF在0.65-0.85 MPa的工作压力和55-70％的回收率下可以达到较高的处理效率。此外，随着进料电导率的增加，有必要在该范围内增加压力并降低回收率以维持有效的操作。本文将为UF / NF双膜工艺设计和操作优化提供指导。压力和回收率对去除效率的影响得到加强，可以在更大范围内调节去除效率。当电导率小于3500μS/ cm时，NF在0.65-0.85 MPa的工作压力和55-70％的回收率下可以达到较高的处理效率。此外，随着进料电导率的增加，有必要在该范围内增加压力并降低回收率以维持有效的操作。本文将为UF / NF双膜工艺设计和操作优化提供指导。85 MPa，回收率55-70％。此外，随着进料电导率的增加，有必要在该范围内增加压力并降低回收率以维持有效的操作。本文将为UF / NF双膜工艺设计和操作优化提供指导。85 MPa，回收率55-70％。此外，随着进料电导率的增加，有必要在该范围内增加压力并降低回收率以维持有效的操作。本文将为UF / NF双膜工艺设计和操作优化提供指导。