Do you know how to extend the life of your reverse osmosis membrane?

Today Susan is here to answer some questions about water treatment equipment, hope it can help you.

Reverse osmosis membrane is an important part of water treatment equipment, widely used in electronics, electric power, automotive, food, medical and other fields. All mechanical equipment has a service life, the service life of water treatment equipment in addition to the design, materials and other factors, but also with the life of the reverse osmosis membrane has a great relationship. Here, water treatment new horizons to share with you how to maintain good reverse osmosis membrane, extend the service life of reverse osmosis water treatment equipment methods and techniques.

After the reverse osmosis equipment test run, two methods are used to protect the membrane. Equipment test run for two days (15 ~ 24h), and then use 2% formaldehyde solution maintenance; or run 2 ~ 6h with 1% NaHSO3 water solution for maintenance (should exhaust the air in the equipment pipeline to ensure that the equipment does not leak, close all the import and export valve). Both methods can get satisfactory results.



Reverse osmosis equipment has residual gas running at high pressure, the formation of air hammer will damage the membrane often occurs in two cases: after the equipment is emptied, re-run, the gas is not exhausted on the rapid increase in pressure operation. Should be in the 2 ~ 4bar pressure will be the remaining air exhaust, and then gradually increase the pressure to run. In the pretreatment equipment and high-pressure pumps between the joints sealing bad or leakage (especially microfilter and after the pipeline leakage) when the reverse osmosis pretreatment water supply is not very sufficient, microfiltration clogging occurs, in the sealing of the bad place due to the vacuum will be sucked into part of the air. The microfilter should be cleaned or replaced to ensure that the piping does not leak. Should be in the flow meter without air bubbles in the case of gradual pressure rise operation, operation found bubbles should be gradually reduced to check the cause.

As the concentration of inorganic salts in the concentrated water side of the membrane is higher than that of the raw water, it is easy to scale and pollute the membrane. Flush with pretreatment water with chemical reagents. Water containing chemical reagents may cause membrane contamination during equipment shutdown. Reverse osmosis equipment in preparation for shutdown, should stop adding chemical reagents, and gradually reduce the pressure to about 3 bar with pretreatment water flushing for 10min, until the TDS of the concentrated water and the TDS of the raw water is very close to the end.

Composite polyamide membrane use of common problems, because the polyamide membrane residual chlorine resistance is poor, in the use of chlorine and other disinfectants are not correctly injected, coupled with the user of microbial prevention of insufficient attention to microbial contamination is likely to lead to microbial contamination. At present, many water treatment equipment manufacturers produce pure water microbial exceeds the standard, is the disinfection, maintenance is not effective caused by. Reverse osmosis equipment does not use disinfectant maintenance; equipment installed without disinfection of the entire pipeline and pretreatment equipment; intermittent operation without disinfection and maintenance measures; no regular disinfection of pretreatment equipment and reverse osmosis equipment; maintenance fluid failure or insufficient concentration.

Reverse osmosis equipment in the process of use, in addition to the normal attenuation of performance, due to pollution caused by the attenuation of equipment performance is more serious. Usual pollution is mainly chemical scale, organic matter and colloid pollution, microbial pollution. Different pollution symptoms are different.

① colloidal contamination: colloidal contamination occurs, usually accompanied by the following two characteristics: pre-treatment in the microfilter clogging very quickly, especially the pressure difference increases very quickly, B, SDI value is usually more than 2.5.

② microbial contamination: microbial contamination occurs, reverse osmosis equipment through the water and the total number of bacteria in the concentrated water are relatively high, usually must not be in accordance with the requirements of maintenance and disinfection.

③ Calcium scale: can be based on the raw water quality and design parameters to determine the