The system and process of desalination using lava seawater for high-efficiency and low energy

The present invention relates to a lava seawater desalination system and method, which comprises a reverse osmosis process in which the progress of desalination process is dependent on salinity. Specifically, the system of the present invention comprises: a water drawing device which draws lava seawater above the ground; a salinity separation unit which separates the lava seawater drawn by the water drawing device into high-salinity lava seawater and low-salinity lava seawater according to salinity thereof; a reverse osmosis unit which comprises a seawater reverse osmosis unit and a brackish water reverse osmosis unit, wherein the seawater reverse osmosis unit filters and separates the high-salinity lava seawater into high-concentration condensed water and first freshwater, the brackish water reverse osmosis unit filters and separates the low-salinity lava seawater into low-concentration condensed water and second freshwater, and the freshwater discharged from the seawater reverse osmosis unit is introduced along with the low-salinity lava seawater into the brackish water reverse osmosis unit to be filtered therein; a freshwater storage tank which stores the freshwater discharged from the brackish water reverse osmosis unit; and a drain water treatment unit which treats the freshwater discharged from the seawater reverse osmosis unit. According to the present invention, the drawn lava seawater is subjected to appropriate desalination process according to its salinity, thereby reducing unnecessary processes and reducing energy consumption; due to absence of foreign materials and harmful substances, a pretreatment process is not needed; by drawing lava seawater from two different layers having different salinities, fish-farming water having optimal temperature and salinity can be supplied to marine fish farms; the energy needed for desalination process can be self-generated through salinity gradient-based power generation, thus minimizing energy consumption. 본 발명은 특히 염도에 따라 담수화 과정이 서로 다르게 진행되는 역삼투 공정이 구비되는 용암해수 담수화 시스템 및 방법에 관한 것으로서, 용암해수를 지상으로 취수하는 취수 장치와, 상기 취수 장치로 취수된 용암해수를 염도에 따라 고염도 및 저염도 용암해수로 분리시키는 염도 분리부와, 고염도 용암해수를 고농도 농축수와 1차 담수로 분리 여과시키는 해수 역삼투부와, 저염도 용암해수를 저농도 농축수와 2차 담수로 분리 여과시키는 기수 역삼투부로 이루어지며, 해수 역삼투부에서 배출되는 담수는 저염도 용암해수와 함께 기수 역삼투부로 투입되어 여과되게 구성되는 역삼투부와, 기수 역삼투부에서 배출되는 담수가 저장되는 담수저장조 및, 해수 역삼투부에서 배출되는 담수가 처리되는 배출수 처리부로 구성됨으로써 취수되는 용암해수 염도에 따라 적절한 담수화 공정을 거치므로 불필요한 공정이 단축되어 담수화 소요 에너지가 절감되고, 이물질 및 유해성분이 없으므로 전처리 공정이 필요 없으며, 용암해수를 서로 염도가 다른 두 층