The role of caustic soda and hydrated lime in wastewater treatment is similar, but in reality, there are subtle differences when they are used. This is also because hydrated lime itself belongs to calcium hydroxide, one of the different physical properties, while the other belongs to flake alkali. Therefore, although both belong to strong alkali properties, there will still be slight differences in the actual sewage treatment process.
1.From the perspective of procurement cost, the price of hydrated lime is much lower than that of caustic soda, and its solubility is not advantageous in sewage treatment. After treatment, more waste is involved, but the effect of using hydrated lime in many special fields may be relatively poor.
2.When reusing hydrated lime, in addition to neutralizing wastewater, the calcium ions in hydrated lime can also undergo redox reactions with some phosphate ions in the wastewater, which will be converted into phosphate precipitation after the reaction, thus achieving good phosphorus removal effect.
3. Their chemical properties are actually similar to their physical properties, but in the process of use, flake alkali also has the functions of breaking emulsions and assisting coagulation.
4. However, due to the small particle size of hydrated lime, it has good solubility in wastewater treatment and will not clog when used in large quantities. It can also be used as a coagulant aid for products such as aluminum sulfate in wastewater treatment. However, caustic soda also has a good treatment effect in regulating acidity and alkalinity.
After introduction, we learned that although caustic soda and hydrated lime are similar, there are still significant differences between them when it comes to wastewater treatment. However, in reality, products with different properties perform differently in different fields, so it is necessary to choose the better one when using them.
