How to determine if the EDI water treatment equipment is contaminated?

EDI Working principle of water treatment equipment:

    EDI is a pure water production technology that combines ion exchange technology, ion exchange membrane technology, and ion electromigration technology (electrodialysis technology). This technology uses ion exchange to overcome the incomplete desalination caused by electrodialysis polarization and uses electrodialysis polarization to produce water electrolysis. H+ and OH- OH−

      EDI The membrane stack mainly consists of alternately arranged anion and cation exchange membranes, concentrate chambers, anion and cation exchange membranes, freshwater chambers, and positive and negative electrodes. Ion exchange resin is sandwiched between the anion and cation exchange membranes to form a single processing unit and constitutes the freshwater chamber, and the units are separated by a mesh to form the concentrate chamber. Under the action of a DC electric field, the cations and anions in the ion exchange resin in the freshwater chamber migrate toward the negative and positive electrodes respectively along the channels formed by the resin and the membrane. Cations pass through the cation exchange membrane, and anions pass through the anion exchange membrane, entering the concentrate chamber to form concentrate. At the same time EDI The cations and anions in the influent exchange with the hydrogen ions and hydroxide ions of the ion exchange resin to form ultrapure water (high-purity water). The super-limit current makes the large amount of hydrogen ions and hydroxide ions produced by water electrolysis continuously regenerate the ion exchange resin. In traditional ion exchange, the ion exchange resin needs to be chemically regenerated intermittently after saturation. However, EDI The resin in the membrane stack is continuously regenerated by water electrolysis, and the operation is continuous, without the need for acid-base chemical regeneration.

EDI Water treatment equipment
    Although EDI The influent conditions of the module greatly reduce the chance of blockage inside the module, but as the water treatment equipment runs for a long time, EDI Blockage may still occur in the internal waterways of the module, mainly EDI The influent contains a large amount of solute, forming desalination precipitation in the concentrate chamber. If the influent contains a large amount of magnesium ions (hardness exceeds 0.8ppm ) co2 and a higher PH value, it will accelerate the precipitation speed. In this case, we can clean the EDI module by chemical cleaning to restore its original technical characteristics.

    1. Usually judging EDI The pollution and blockage of the module can be evaluated and judged from the following aspects:
    1 The pressure difference between the concentrate water inlet side and the product water side is higher than the original data when the influent temperature and flow rate remain unchanged. 45%。
    2 The pressure difference between the concentrate water inlet side and the concentrate water outlet side is higher than the original data when the influent temperature and flow rate remain unchanged. 45%。
    3 The product water quality (resistivity) decreases significantly when the influent temperature, flow rate, and conductivity remain unchanged.
    4 The concentrate water discharge decreases when the influent temperature and flow rate remain unchanged. 35%。

    2. The main causes of module blockage are as follows:
    1 Particle / Colloid blockage
    2 Inorganic blockage
    3 Organic blockage
    4 Microbial blockage

    3. EDI Cleaning notes:
    Before cleaning or disinfection, select the appropriate chemical reagents and be familiar with the safety operating rules. Never perform chemical cleaning when the component power is not cut off.