When the water temperature rises, in some reverse osmosis systems operating at constant flow, the desalination rate of the system will decrease. This is because the viscosity of the water increases and the water flux increases. If the constant flow operation is continued, the operating pressure required to produce the same flow of water will decrease. The decrease in operating pressure will result in a decrease in the desalination rate and subsequent desalination. The regeneration cycle of the device is also shortened at the same time.
In order to keep the desalination rate of the system unchanged, it is necessary to adopt constant pressure operation, but at this time, the water production will increase, and as the temperature rises, the water production will continue to increase. Therefore, under the condition of high water temperature, the maintenance of system performance needs to be adjusted according to actual needs.
However, the problem of high water temperature on system maintenance is not only these, the greater danger comes from microbial contamination. The water temperature in summer is mostly 15-30 ℃, and this temperature is also a suitable condition for the growth of most bacteria. As the water temperature rises, the bacterial metabolic rate and growth rate increase accordingly. Once the microorganisms enter the RO system, they will reproduce and grow with the help of the nutrients concentrated in the RO concentrated water section, and even survive in the water production section. In a hot water environment, microorganisms multiply rapidly, and a biofilm layer can be formed on the surface of the RO membrane within a few days, resulting in a rapid increase in the pressure difference between the inlet and outlet water of the RO system, a rapid decline in the water production and desalination rate, and a rapid decline in the product water. contaminated.
Biofouling causes the coiled module diaphragm to shrink, a phenomenon known in the industry as a "telescope".
