1. Oxidation, hydrolysis, polymerization and other processes occur in the production of polymeric ferric sulfate. Oxidation and polymerization are exothermic reactions, hydrolysis is endothermic reaction, and the three reactions are carried out at the same time. After the reaction is completed, the semi-finished products under high temperature still undergo hydrolysis and polymerization. At this time, it is necessary to stand and cool to prevent the hydrolysis reaction from continuing rapidly.
If the product is still loaded and transported under high temperature, it will change the equilibrium movement of hydrolysis reaction during transportation, which will aggravate the hydrolysis reaction and form the precipitation of iron hydroxide gel, resulting in yellowing and yellowing of the product. Moreover, iron hydroxide gel precipitation is included in the detection of total iron content, but it can not play the role of adsorption, neutralization, bridging and net capture. At the same time, the negative charge of iron hydroxide gel precipitates the positive charge of a part of the polynuclear hydroxyl complex and consumes the effective iron content of the product.
2. Tank cars, barrels and other containers loaded with liquid polyferric sulfate shall be cleaned to avoid the introduction of pollutants. When the product arrives at the customer's storage, check whether there are other chemicals or moisture residues in the original storage tank.
3. The two most important factors affecting the use effect of polymeric ferric sulfate are dosage and pH value. The mechanism of coagulation treatment of wastewater from different customers is also different. Some play a major role in adsorption, electric neutralization, and some play a major role in bridging and net capture. Therefore, the dosage and pH value must be measured and recorded in the process of small-scale test and pilot test. The relationship between the results after treatment and the influence of dosage and pH value shall be analyzed, and the products shall be adapted according to the analysis results.
At the same time, during the small-scale test, it is necessary to carry out the comparison experiment of multiple dosage, which can cover the comparison of effects under different dosage and pH value. For example, some pollutants can be transformed from liquid phase to solid phase at pH 4.5, and finally removed by adsorption precipitation. Then, in the comparative experiment, the two types of polyferric sulfate should be added to the point where the pH value is less than 4.5 in order to make an effective comparison.
