1. Water Chemical
These chemicals are used in raw water treatment systems to become water suitable for consumption or industrial process water. Its functions include:
- 
Coagulation & Flocculation 
 Bringing fine particles together so that they can settle.
 Example: Aluminum Sulfate (alum), Poly Aluminum Chloride (PAC), Ferric Chloride.
- 
Disinfection 
 Kills harmful microorganisms.
 Examples: Chlorine, Sodium Hypochlorite, Ozone, UV treatment.
- 
Corrosion & Scale Control (Scale Inhibitor) 
 Prevents scale and rust on pipes or boilers.
 Examples: Phosphate-based inhibitors, Sodium Polyacrylate.
- 
pH Adjusters 
 Maintain the acid-base balance of water.
 Examples: Sodium Hydroxide (NaOH), Sulfuric Acid (H₂SO₄), Lime (Ca(OH)₂).
2. Waste Water Chemical
These chemicals are used to treat domestic and industrial wastewater before it is discharged into the environment. The goal is to reduce the pollutant content (BOD, COD, TSS, heavy metals, etc.).
Main types of chemicals:
- 
Coagulants & Flocculants 
 To settle suspended solids.
 Examples: PAC, Ferric Chloride, Polyacrylamide (PAM).
- 
Defoamer (Anti-foam) 
 Eliminates foam in aeration systems.
- 
Microbial Nutrients (for biological processes) 
 Supports microbial growth in biological reactors.
 Examples: Urea, Phosphate compounds.
- 
Final disinfectant 
 Kills pathogenic bacteria before water is discharged.
 Example: Chlorine, Sodium Hypochlorite.
3. Application Examples in Industry
- 
Food/beverage plants: ensure process water is clean and microbe-free. 
- 
Textile/metal plating plants: reduces color and heavy metals from effluents. 
- 
Power plant / Petrochemical industry: prevents scale and corrosion in boiler systems and cooling towers. 
