Water supply and process water treatment (separation, concentration, classification and purification)
In various industrial production processes, there are often demands for separation, concentration, classification and purification of certain aqueous solutions. The traditional methods used are precipitation, filtration, heating, freezing, distillation, extraction and crystallization. These methods show the shortcomings of long process, high energy consumption, high material loss, huge equipment, low efficiency, and cumbersome operation. Replacing a certain traditional technology with ultrafiltration membrane technology can obtain significant economic benefits.
The reverse osmosis system ultimately needs to be cleaned. It is recommended that you clean the RO system before your RO system shows a tendency to be contaminated, before it is out of service for a long time, or when routine maintenance is scheduled. When the following pollution characteristics appear (standardized water production decreased by 10-15%, after standardized production water quality decreased by 10-15%, or the pressure drop between feed water and concentrated water increased by 10-15%), it indicates that your RO system needs Cleaned.
Since the RO system is dirty and the frequency of cleaning is different depending on the location, the generally acceptable cleaning frequency is once every 3 to 12 months. If you have to clean more than once a month, you should improve the RO pretreatment system and adjust the operating parameters of the RO system. If you need to clean once every 1 to 3 months, you need to improve the operating level of the current equipment. Work, but it is difficult to judge whether the preprocessing system needs to be improved.
In RO design, the use of RO product water to flush the dirt in the system is usually neglected. This method can reduce the number of RO cleanings. Soaking RO membrane modules with product water during equipment shutdown can help dissolve scale and loose deposits, thus reducing the frequency of chemical cleaning.
It is usually necessary to use various cleaning chemicals in a specific order to obtain the best cleaning effect. For example, first use a low-pH cleaning to remove substances such as scale, and then use a high-pH cleaning solution to remove organic matter. However, sometimes a high-pH cleaning solution is used to remove oily dirt first, and then a low-pH cleaning solution is used. Some cleaning fluids are also added with detergents, which will help to remove severely polluted biological and organic impurities. Other cleaning add chelating agents like EDTA, these chelating agents help to remove colloids, organic matter, biological impurities and sulfate scale. It must be remembered that incorrect selection of cleaning chemicals or incorrect cleaning steps may make the fouling more serious.
