Causes of fouling in ultrafiltration system:
(1) The inlet water temperature of ultrafiltration is too low, resulting in the increase of operation resistance;
(2) Ultrafiltration membrane fouling is caused by raw water pollution, too many bacteria and algae, that is, the SDI of influent is too high, resulting in ultrafiltration fouling;
(3) The influent flow of ultrafiltration increases, which exceeds the water production capacity of the filter membrane;
(4) The inlet pressure is too high. In order to increase the water production, artificially increase the inlet pressure of ultrafiltration.
When ultrafiltration is polluted, it will have a great impact on RO system and increase pollution blockage, mainly in the following aspects:
(1) The water quality deteriorates, the SDI value becomes higher or exceeds the standard, and the color of the SDI value test diaphragm becomes darker;
(2) The reverse osmosis membrane is polluted and blocked, resulting in the rapid decline of water production rate of the reverse osmosis system;
(3) When the UF is seriously polluted, a layer of "sponge" will be generated in the UF. During chemical cleaning, the residual NaOH or sodium hypochlorite can not be washed in time, which will be released slowly, which will bring serious harm to the subsequent RO system.
