Reverse Osmosis System Case

In view of the microbial contamination in reverse osmosis water treatment system, Reverse Osmosis System the causes and hazards of microbial contamination in reverse osmosis membrane were analyzed. The methods of microbial contamination prediction and simple identification were given, Reverse Osmosis System and the measures and methods of microbial contamination control were provided. 

Key words: reverse osmosis membrane; microbial contamination;

From 1953, the use of reverse osmosis technology to dilute the sea water, Reverse Osmosis System to the 20th century, 60 years of commercial operation, to today after 50 years of development, reverse osmosis water treatment technology successfully used in many areas. From the reverse osmosis technology initially used only for desalination, and later gradually expanded to brackish water desalination, Reverse Osmosis System food processing, medicine and health, beverage purification, ultra-pure water preparation, etc., produced a high economic efficiency.

In the process of reverse osmosis water treatment system, if the system design is unreasonable or improper operation control, there will be a film pollution situation. In the several types of membrane fouling (precipitation pollution, microbial contamination, colloidal pollution, etc.), Reverse Osmosis System microbial contamination has its particularity, it is in the reverse osmosis water treatment caused by the operation is the most serious one. At present, the domestic reverse osmosis water treatment system in operation, Reverse Osmosis System the membrane of microbial pollution problems become increasingly prominent. 

Biological pollution refers to the phenomenon that microbes accumulate at the membrane-water interface and thus affect system performance. Microbial contamination is the result of complex interactions between membrane materials, Reverse Osmosis System flow parameters (such as lysates, flow rates, pressures, etc.) and microbes. Microbial contamination is essentially a matter of biofilm growth. 

The main source of microbial contamination is RO feed water. Due to the presence of microbes in surface water and shallow groundwater, the pretreatment system is not working properly, Reverse Osmosis System the microorganisms will enter the RO components, and the moisture inside the RO components will provide an ideal environment for microbial growth. If the micro- Not to kill, these microbes will be reverse osmosis membrane as the carrier with the reverse osmosis concentrated water nutrients and growth, in the warmer conditions, Reverse Osmosis System the growth of microorganisms is more rapid, within a few days can be in the anti- The surface of the permeable membrane forms a biofilm layer, resulting in a rapid increase in the pressure difference between the inlet and outlet of the reverse osmosis system, rapid drop in water production and desalination rate, and contamination of the product water. Reverse Osmosis System On the other hand, pretreatment may also be a source of microbial contamination, Reverse Osmosis System such as the removal of excess flocculants from suspended solids, providing a suitable growth environment for microorganisms.

Prediction and simplification of microbial contamination

(1) Determine the total number of bacteria (TBC) from the raw water inlet, pre-treatment reverse water infiltration water, concentrated water and reverse osmosis product water, and calculate the bacterial change value. Reverse Osmosis System If the concentration of TBC in concentrated water is significantly increased, Reverse Osmosis System indicating that there may be mud on the reverse osmosis membrane formation. 

(2) organic matter in the water can not only form a membrane of its own pollution, but also as a breeding nutrient nutrients. So the organic matter (in terms of total organic carbon, Reverse Osmosis System referred to as TOC) to monitor the film manufacturers prompted to control TOC <2mg / L (in C). 2mg / LTOC roughly equivalent to 5mg / L total organic biomass This value in normal operation, Reverse Osmosis System will not cause inter-membrane organic fouling.

(3) A simple way to check for microbial contamination is to scrape a small portion of the contaminants from the surface and burn it on the flames, which smell the same as the smell of hair burning.