Chemical & Physical

Wastewater treatment combines both physical and chemical methods to effectively remove pollutants. These standard techniques are widely used in treating domestic, industrial, and municipal wastewater. The process involves steps like sedimentation, filtration, chemical reactions, and disinfection to ensure clean and safe discharge.

Physical Processes

Physical treatment focuses on removing solid and suspended particles without altering their chemical structure. Typically, this is the first stage in the treatment process.
Screening: Large debris such as plastics, leaves, and sticks are removed using bar screens or mesh filters.
Sedimentation (Clarification): Heavier solids settle at the bottom of sedimentation tanks, forming sludge. Meanwhile, oils and grease float to the surface and are skimmed off.
Flotation: Air bubbles are introduced to lift lighter materials like grease and oils, making them easier to remove.
Media Filtration: Fine particles and impurities are captured using filters made of sand, gravel, or membranes.

Chemical Processes

In contrast, chemical treatment alters the composition of wastewater through the addition of specific agents to eliminate harmful substances.
Coagulation and Flocculation: Chemicals like aluminum sulfate (alum) or ferric chloride are added to bind fine particles into larger flocs, which can then be removed by sedimentation or filtration.
pH Adjustment (Neutralization): Acids such as sulfuric acid or bases like lime are used to balance the pH, enhancing treatment efficiency and supporting biological activity.
Oxidation: Agents like chlorine, ozone, or hydrogen peroxide break down organic matter and neutralize hazardous substances.
Disinfection: To eliminate pathogens, methods such as chlorination and ozonation are employed before water reuse or release.
Precipitation: The use of lime or alum helps extract heavy metals and phosphates by converting them into filterable solids.