Summarize the application method and proportion of PAC in papermaking industry (I) Summarize the application method and proportion of PAC in papermaking industry (I) Effect of PAC and PAC in the treatment of papermaking wastewater According to the statistical data in recent years, at present, China's papermaking wastewater discharge accounts for 15% of the total industrial wastewater discharge; COD discharge accounts for the total amount of industrial COD discharge in China Of 1/3 or more. The pollution and damage of papermaking wastewater have drawn people's attention. Because papermaking wastewater contains refractory substances such as lignin and cellulose, high chroma and high content of fine colloidal substances, it is suitable for pretreatment or deep treatment with polyaluminum chloride coagulation method because the pulp is negatively charged, and usually the cation Type polymer coagulant, at the same time from the compressed double-layer, adsorption and electricity absorption, bridging, net arrest and so on, so that the pollutants in the wastewater destabilization and aggregation into large micro-floc, and then from the wastewater Do not separate out, sedimentation good effect. The coagulants widely used by paper mills are polyaluminum chloride (PAC) and polyaluminum chloride (PFC), which not only have low cost but also can be used as papermaking materials after PAC treatment. Therefore, it has high economic value. The activated sludge was not affected when the dosage of PAC and PFC was less than 30mg / L, and the effect of PFC on activated sludge was less than that of PAC, which was beneficial to the subsequent treatment of activated sludge. The results showed that when PAC polyaluminium chloride was used to treat papermaking waste water, pH value was 8 and dosage was 6mL, the wastewater treatment effect was better. At the moment, the decolorization rate of wastewater reached 78% and the removal rate of CODCr was up to 37%. In the selection of polymeric ferric chloride coagulant for the treatment of papermaking wastewater, pH value of 8, the dosage of 6mL, the wastewater treatment is better, at this moment the decolorization rate of wastewater up to 90%, CODCr removal rate of up to 43%. This filter source water is original, for reprint, please indicate the source URL: http://www.gyzhenyu.com