Chemical wastewater treatment

Basic concepts of chemical wastewater treatment

Chemical wastewater treatment refers to the process of changing the chemical or physical 

properties of pollutants in wastewater through chemical reactions, transforming them from 

a dissolved, colloidal, or suspended state to a precipitated or floating state, or from a solid 

state to a gaseous state, and then removing them from water. Chemical wastewater treatment 

methods include wastewater neutralization treatment, wastewater coagulation treatment, wastewater 

chemical precipitation treatment, wastewater oxidation treatment, wastewater extraction treatment, etc.

Specific methods for chemical wastewater treatment

Chemical precipitation method: adding a chemical substance called a precipitant to wastewater to 

react with certain soluble pollutants in the water, generating compounds that are difficult to dissolve 

in water, thereby reducing the concentration of pollutants. This method is commonly used to remove 

heavy metal ions and nutrients.

Redox method: Through redox reactions, toxic and harmful substances are converted into non-toxic 

or low toxicity substances. Common oxidants include ozone, hydrogen peroxide, potassium permanganate, etc., 

while reducing agents include iron powder, zinc powder, etc.

Coagulation treatment method: Colloids and suspended solids are condensed into larger particles by 

adding coagulants, and then removed by precipitation or air flotation methods.

Extraction treatment method: By utilizing the difference in solubility of solutes in two immiscible solvents, 

solutes are transferred from one solvent to another to achieve separation.