According to the news on May 5, 2014, from Putuo News Network, “through the pretreatment of sedimentation pool, filtration pool etc, then via RO membrane treatment, and mineralization etc., muddy seawater turns into clear fresh water to enter into every household through pipe net ”. Presently the reporter was informed from Liuheng Water Affair Company that the largest seawater desalination equipment of unit capacity in whole the city----- the first unit of seawater desalination machine-set with 12500 ton /d of Liuheng Seawater Desalination 2nd Phase Project, showed better performance after commissioning for one week, and its performance test has been completed.
According to the introduction by Fu Hongbing, the engineer of Hangzhou Water Treatment Technology Development Center (the Center for short), up to April 30, 2014, the machine-set has operated accumulatively for 7 days and nights. Presently the output of the machine-set is 500 ton / h; its operational condition is better. “According to the test, now the effluent quality basically conforms to that of the first phase project, even the effluent quality will be further improved due to the equipment renewal. Previous to this, the fresh water produced from the commissioning has been supplied to resident family through the municipal tap water pipe net.” said Mao Jia, the chief engineer and vice general manager of Liuheng Water Affair Company, to the reporter.
It was introduced that, compared with 1st phase project, 2nd phase project pays more attention to lowering energy consumption. In the stage of pretreatment, the latter adopts V-type filtration tank with greater filtration quantity and more fine filtration rather than the former’s non-valve filtration tank. In addition, in order to ensure the effluent quality, the design of sealing type with cover was adopted for the effluent hole of the latter’s fresh water.
Mr.Mao Jia told the reporter that after the seawater is pumped in tank, through initial sedimentation in sediment tank, then, the seawater enters into V-type filtration tank and multi-media filter to carry out fine filtration, through three-step pretreatment, then it enters into the main machine for seawater desalination. Through treatment by RO membrane in main machine, only the fresh water with high purity water molecules remains, then the fresh water further is treated by mineralization to improve mouthfeel, finally it is done disinfection treatment and supplied to local residents. The effluent quality of 1st phase and 2nd phase projects both is kept at 0.01～ 0.03, being far lower than turbidity 1 of the national tap water standard. It was understand that Liuheng seawater desalination project at 100,000 ton/d level shall be constructed in four phases; the investment for 2nd phase project is about RMB 130 million yuan; the project began to be constructed in May 2011; its scale is 30000 ton/d fresh water; after the first unit of machine set with capacity 12500 ton/d put into production, its second machine set has been carrying out optimization design. After whole the 2nd phase project completed, the seawater desalination capacity at Liuheng shall reach to 50000 ton/d, can effectively guarantee the industrial and domestic water for Liuheng and surrounding islands.