Application of defluorination of aluminum sulfate

The addition of aluminum sulfate for defluorination treatment is to ensure that the fluoride content in the wastewater meets the standard, avoiding fluoride pollution or excessive fluoride intake by the human body leading to fluoride poisoning. Fluorosis can form deposits on teeth and bones, and can cause symptoms such as loss of appetite, dizziness, headache, and memory loss. Aluminum sulfate defluorination is carried out through its adsorption precipitation and complexation precipitation. By adjusting the pH, aluminum sulfate is used to treat fluorine-containing wastewater based on the principle of neutralization and symbiotic precipitation. Arsenic, fluorine, and other substances precipitate at their appropriate pH values, thereby separating from the water.

On the other hand, the aluminum hydroxide colloid generated by the dissolution of aluminum sulfate in water has adsorption and precipitation effects on solid suspended small particles in water, and aluminum ions can undergo electrical neutralization reactions with it. Firstly, there is the treatment of wastewater contaminated with fluorine. Traditional treatment methods involve adding calcium salts to the wastewater, but this results in a slow sedimentation rate and increases the cost of treatment when used alone. But adding iron free aluminum sulfate has a completely different effect. Its main function is chemical precipitation, adsorption or flocculant treatment of pollutants, greatly reducing the fluoride content in wastewater. The precipitation method is only applicable to the treatment of wastewater with high fluoride content; For the treatment of low fluoride content, such as drinking water, we need to use adsorption method. The commonly used method is to first use chemical precipitation, and then treat aluminum sulfate with adsorbents or flocculants to reduce the fluoride content to below 10 mg/L.

Next is the treatment of heavy metal wastewater. The treatment methods for heavy metal wastewater include neutralization precipitation method, sulfurization soda method, ferrite method, resin method, etc. Iron free aluminum sulfate precipitation is also the most commonly used type. Non ferrous aluminum sulfate also has adsorption and sedimentation effects on heavy metal wastewater, which is also a method adopted by many enterprises in wastewater treatment. In order to improve its defluorination effect, some coagulants and regulators can be added to the wastewater, such as commonly used lime, polyacrylamide, etc.