In addition, pollution is often not a single, the symptoms of its performance also have certain differences, making the identification of pollution more difficult.
Identify the type of pollution to integrate raw water quality, design parameters, pollution index, operating records, equipment performance changes and microbial indicators to determine:
(1) colloidal pollution: colloidal pollution occurs, usually accompanied by the following two characteristics:
A, pre-treatment in the microfilter clogged quickly, especially the differential pressure increases quickly.
B, SDI value is usually above 2.5.
(2) Microbial contamination: When microbial contamination occurs, the total number of bacteria in the permeated water and concentrated water of RO equipment is relatively high, and usually there must be no maintenance and disinfection as required.
(3) calcium scale: can be based on raw water quality and design parameters to determine. For carbonate water, if the recovery rate is 75%, when the design is added scale inhibitor, the LSI of the concentrated solution should be less than 1; when no scale inhibitor is added, the LSI of the concentrated solution should be less than zero, and generally no calcium scale will be produced.
(4) Can be used 1/4 inch PVC plastic pipe inserted into the component to test the performance changes of different parts of the component to judge.
(5) Judge the type of contamination according to the change of equipment performance.
(6) can be acid washing (such as citric acid, dilute HNO3), according to the effect of cleaning and cleaning fluid to determine the calcium scale, further confirmed by cleaning fluid composition analysis.
(7) chemical analysis of the cleaning fluid: take the original water, cleaning fluid, cleaning fluid, three samples of analysis.
After determining the type of contamination, can be cleaned according to the method in Table 1, and then disinfected and used. In the type of contamination can not be determined, usually use cleaning (3) + disinfection + 0.1% HCl (pH 3) steps to clean.