The role of anhydrous sodium sulfite and sodium chlorite in sewage treatment

Sewage treatment is an important process of water pollution control. Use physical, biological, chemical and other methods to treat industrial wastewater and domestic sewage, separate solid pollutants, reduce organic pollutants and eutrophication in water (mainly nitrogen and phosphorus compounds), and reduce environmental pollution.

Anhydrous sodium sulfite is white hexagonal prism crystals, soluble in water (12.54g/100ml water at 0℃; 283g/100ml water at 80℃). At 33.4°C, the solubility is about 28% higher. The aqueous solution is alkaline with a pH of about 9-9.5. Slightly soluble in alcohol, insoluble in liquid chlorine and ammonia. It is easily oxidized into sodium sulfate in the air and decomposed into sodium sulfide at high temperature. To enhance the reducing agent, sodium bisulfite is formed by reacting with sulfur dioxide, and the corresponding salt is formed by reacting with a strong acid.

　　Sodium chlorite is soluble in water (34% at 5°C and 46% at 30°C). When heated to 350 ℃, anhydrous materials will not decompose. Generally speaking, the product will decompose because of water when heated to 180-200℃. The alkaline aqueous solution is stable to light, while the acidic aqueous solution will explode and release chlorine dioxide under the influence of light. Strong oxidant, its oxidizing capacity is 4-5 times of bleaching powder, 2-3 times of bleaching powder. Contact with combustibles and organic compounds can cause an explosion.

　　Through a brief introduction to the role of anhydrous sodium sulfite and sodium chlorite in wastewater treatment, I believe you have a deeper understanding of anhydrous sodium sulfite.