However, in recent years, the tap water purification plants in major cities such as Beijing, Shanghai, and Guangzhou have improved the pretreatment and advanced treatment by modifying the tap water processing technology, which has improved the water quality of the waterworks. Most of the tap water has reached the national life when it leaves the factory. Drinking water standards. Because of the pipeline, the water coming out of each household faucet is still contaminated to varying degrees. Tap water is the main source of drinking water for urban and rural residents, so the problem of tap water pollution cannot be ignored. According to incomplete statistics, some indicators of terminal tap water supplied by 76% of waterworks in the country have not yet reached national standards. Therefore, the key to solving people's drinking water is to solve the water quality of the terminal tap water.

（1）Secondary pollution of pipelines: Due to the aging and spalling of water pipelines, various suspended materials are produced, which brings further secondary pollution to tap water;

（2）the pollution of the water tank: Most high-rise water tanks have no special care, long-term cleaning, sealing conditions are not good, so it is easy to breed bacteria, viruses, etc., more and more deposits in the water tank, long moss, serious Contaminated tap water quality Ultrafiltration use: Effectively remove suspended solids such as sediment and rust from tap water, and trap bacterial viruses such as Escherichia coli, flagellates, and phage to remove chlorine.

2. The analysis of the way to solve the pollution of tap water

（1）Protection of water source: The isolation and protection of water source can guarantee the pollution of water quality to a certain extent, but it cannot fundamentally solve the secondary pollution problem of water pipelines and high-rise buildings;

（2）Renovation of water supply plant: The investment in water purification technology and equipment transformation cost is large, and it can not be implemented in every city in a short time. Moreover, the main reason is to transform the water supply network, which is even more difficult;

（3）Pipeline quality water supply: Pipeline quality water supply is generally limited to some new residential areas, but the construction is difficult, the equipment and pipe network maintenance is troublesome, the input cost is high, the water fee is high, and it is difficult to guarantee. Every owner can accept it.

Solution:

Ultrafiltration membrane technology applies ultrafiltration to household terminal water purifiers: the household terminal water purifier is directly installed on the domestic water pipeline, the ultrafiltration membrane life can be used for deep filtration of tap water, and the ultrafiltration membrane pack effectively removes tap water by two. The rust, colloid and bacteria produced by the secondary pollution reduce the turbidity, and the water production reaches the national direct drinking water standard.

Advantages of ultrafiltration for domestic water use:

1. Ultrafiltration can completely remove bacteria, viruses, etc. from water, and retain the trace elements needed by the human body;

2. Ultrafiltration can completely remove algae;

3. Ultrafiltration can completely remove chlorine from tap water;

4. Ultrafiltration application in the household water purifier than the general water purifier effluent water, can fully meet the domestic water consumption of a family;

5.Ultrafiltration water purifier is simple to install, easy to use, obvious effect, low cost of use.