青岛某市政用途全流程海水淡化厂工艺设计

Process Design of a Whole-process Seawater Desalination Plant for Municipal Water Supply in Qingdao

青岛某市政海水淡化工程设计产水规模为10×104m^(3)/d,产水拟并入城市供水管网,采用“一级预处理(气浮)+二级预处理(超滤)+脱盐(两级反渗透)+后处理(矿化滤池)”的全流程工艺方案。其中高速气浮池表面负荷为24.92 m^(3)/(m^(2)·h);超滤系统设计膜通量为41.4 L/(m^(2)·h),回收率不低于92%;一级反渗透设计通量为13.11 L/(m^(2)·h),回收率45%;二级反渗透设计通量为36.86L/(m^(2)·h),回收率90%;反渗透产水再经过矿化滤池增加水中硬度,产水水质稳定达到生活饮用水卫生标准。工程投资概算为7.44亿元,单位制水成本为4.86元/m^(3),其中可变成本为2.92元/m^(3)。

The designed scale of a municipal seawater desalination project in Qingdao is 10×10~4m~3/d.The product water is planned to be connected to the municipal water supply network.The whole process consists of primary pretreatment(air flotation),secondary pretreatment(ultrafiltration),desalination(two-stage reverse osmosis)and post-treatment(mineralized filter).The surface load of the high-speed air flotation tank is 24.92m^(3)/(m^(2)·h).The membrane flux of the ultrafiltration system is 41.4L/(m^(2)·h),and the recovery rate is not less than 92%.The design flux of the first stage reverse osmosis is 13.11 L/(m^(2)·h),and the recovery rate is 45%.The design flux of the secondary stage reverse osmosis is 36.86 L/(m^(2)·h),and the recovery rate is 90%.The water produced by reverse osmosis is then passed through the mineralized filter to increase its hardness,and the quality of the produced water stably meets the sanitary standard of drinking water.The investment of the project is estimated to be 744 million yuan,and the unit water cost is 4.86 yuan/m~3,among which the variable cost is 2.92 yuan/m~3.