Water treatment system

A water treatment system for producing tap water or industrial water from raw water such as river water, lake water, and groundwater, the system comprising:

• a raw water tank which stores raw water;
• a filtration membrane module which receives raw water from the raw water tank and has a filtration membrane for separating and removing foreign substances from the raw water;
• a feed pump which is provided between the raw water tank and the filtration membrane module, and feeds raw water from the raw water tank to the filtration membrane module;
• a filtered water tank which receives and temporarily reserves filtered water transmitted through the filtration membrane of the filtration membrane module, and sends out a supernatant as treated water;
• a backwash pump which is provided between the filtered water tank and the filtration membrane module, and flows filtered water backward from the filtered water tank to the filtration membrane module;
• a valve and a channel which are provided between the filtered water tank and the filtration membrane module, and switch the direction of the water flow between the forward and reverse directions;
• a control means for suspending the supply of raw water from the raw water tank to the filtration membrane module, switching the valve and channel to the reverse direction, making the backwash pump to supply filtered water from the filtered water tank to the filtration membrane module thereby backwashing the filtration membrane;
• a cyclonic ultraviolet irradiation reactor provided between the filtration membrane module and the raw water tank, for treating backwashing drainage generated by backwashing of the filtration membrane, and returning the water to the raw water tank;
• a second ultraviolet irradiation reactor provided between the filtration membrane module and the raw water tank, for treating backwashing drainage generated by backwashing of the filtration membrane, and returning the water to the raw water tank;
• and
• a bypass line which is branched from a line at an ejection side of the backwash pump, and merges with an incurrent line of the cyclonic ultraviolet irradiation reactor bypassing the filtration membrane module.