Coagulants in Wastewater Treatment

In wastewater treatment, coagulants are chemicals that aid in the clarification and removal of suspended solids. This ensures that your influent raw water can be reused as process water or meet wastewater discharge regulations.

Benefits of Coagulants in Wastewater Treatment

Aquasan’s will help you determine and optimize your coagulant for your specific challenges:

  • Reduce costs
  • Reduce handling and freight costs
  • Increase safety by choosing less hazardous coagulant
  • Increase safety by reducing the amount of handling
  • Reduced sludge production and volumes
  • Overcome slow coagulation in cold water
  • Optimization of chemistry to meet discharge requirements


Our coagulants have been successfully applied in water clarification for the Food Industry, Landfills, general industrial wastewater industries, Phosphorus removal and many other applications.

Organic vs Inorganic Coagulants

Organic Coagulants 

For certain water sources, organic coagulation is more appropriate for charge destabilization. Organic coagulants are generally used when a reduction in sludge generation is desired.

Examples of organic coagulants used at Aquasan are:

  • PolyDADmac, Polyamines or tannins

Inorganic Coagulants 

Inorganic coagulants can be applied for a broad variety of wastewater. Inorganic coagulants have a really large spectrum of operation and are also particularly effective on raw water with low turbidity (total suspended solids concentration) and will be more cost-effective and offer a higher performance over organic coagulants.

Once the inorganic coagulant is added to water, the metal ion (Al3+ or Fe3+) is hydrolysed to form aluminium hydroxide or iron hydroxide floc as well as hydrogen ions (H+). Colloidal mater is removed by adsorption onto/within the metal hydroxide hydrolysis products that are formed, and is sometimes referred to as the sweep floc coagulation. The hydrogen ions will react with the alkalinity of the water and in the process, decrease the pH of the water can be seen. Aquasan also offers alcaline coagulants for already acidic waters. 

Inorganic coagulants are largely aluminium or iron based. Examples of inorganic coagulants used at Aquasan are: 

  • Ferric sulfate 
  • Ferric chloride 
  • Sodium Aluminate
  • Aluminum chloride 
  • Poly aluminum chloride 
  • Aluminum sulfate 
  • Aluminum chlorohydrate

At Aquasan, our experts are ready to talk to you about the applications you need, provide a quote, and visit you on site to see your organization first hand.