The main component of microbial flocculants is microbial cells or their secondary metabolites. It has the characteristics of wide application range, high flocculation activity, safety, harmlessness, and easy biodegradability, so it can be widely used in the treatment of water supply, sewage and wastewater.

Application of Microflocculation of Cooling Water Treatment Agent

If the colloid in the raw water is flocculated or coagulated before filtration, the efficiency of the media filter can be greatly improved, and the SDI of the effluent can be reduced to about 5. Ferric sulfate and ferric chloride can be used to destabilize the negative charge on the surface of the colloid, and capture the colloid on the new ecological ferric hydroxide microfloc. The principle of using aluminum-containing flocculant is similar, but because of its possibility There is a problem of residual aluminum ion pollution, and it is not recommended to use it unless polymerized aluminum is used. It is very important to disperse and mix the flocculant quickly. It is recommended to use a static mixer or set the injection point in the suction section of the booster pump. Usually the best dosage is 10-30mg/L, but the dosage should be determined for specific projects. quantity.

In order to increase the strength of the cooling water treatment agent-coagulant flocs to improve their filtration performance, or to promote the bridging between colloidal particles, the flocculant is used together or alone with the coagulant. The flocculant is a soluble polymer organic compound. , Such as linear polyacrylamide, through different active functional groups, they may be cationic, anionic or neutral non-ionic. Coagulants and flocculants may directly or indirectly affect the RO membrane, such as their reaction products forming precipitation and covering the membrane surface, for example, when the filter is channeled and the coagulant flocs pass through the filter and Precipitation occurs; when iron or aluminum coagulant is used, but the pH value is not lowered immediately, precipitation will occur during the RO stage or the supersaturation induced by the influent concentration, and the addition of compounds after the multi-media filter will also produce For precipitation reactions, the most common is to add scale inhibitors. Almost all scale inhibitors are negatively charged and will react with cationic flocculants or coagulants in the water to contaminate the RO membrane.

When the added polymer itself affects the membrane and leads to a decrease in flux, this is a direct effect. In order to eliminate the direct and indirect effects of RO/NF membranes, anionic and non-ionic flocculants are more suitable than cationic flocculants, and excessive addition must be avoided.