Consumables (Chemicals)

There are mainly three types of chemicals are used in our WetSep® system to facilitate the filtration of impurities in wastewater. The three types of chemicals are namely coagulant, flocculant and acid.
Coagulant


Wastewater contains small particles that suspend in water forming a colloid. They carry same charges and oppose each other, preventing the formation of larger particles. Coagulant is added to neutralize the charge in order to allow the particle easier to flocculate which results in faster sedimentation performance.

Over dosage of coagulant will hinder coagulation as colloids will be re-stabilized due to charge reversal. The increased surface charges lead to the increase of electrostatic repulsion force. Hence, particles are difficult to coagulate upon collision.

Commonly used coagulants are Alum, Polyaluminium chloride (PAC) and Polyaluminium ferric chloride (PAFC). The coagulant we choose for WetSep® is PAFCFor detailed information on the consumption rate, please refer to the consumption chart below. (#27F).



Particles settle faster if they are heavier. By dosing flocculants into water, particles form bigger flocs. The larger the flocs size, the faster the particles settle by gravity. Hence increases the sedimentation rate.

Polymers (anionic or cationic) are one of the most common and effective flocculants used in the water treatment industry. Polymer chains formed attach to multiple particles in wastewater. Larger yield and tougher flocs are formed through inter-particle bridging. However excessive polymer, on the other hand, will saturate the available binding site on the surface of the particles and hinder the formation of larger flocs. The flocculant we choose for WetSep® is Emulsified polymer (#26E).

Flocculant


The pH of treated effluent is commonly required to range between 6-9. Since the addition of coagulant and flocculant during the treatment would change the pH of the effluent, neutralization of effluent is required to meet the standard. In addition, charges of common coagulant and flocculant also depend on the pH condition. Thus, their performance will be hindered if the working environment is beyond their optimal pH range. Therefore, pH adjustment is necessary to achieve the best performance.

Sulphuric acid is used almost universally for the neutralization process. Sulphuric acid has high effectiveness and strong acidic nature. The common concentration we choose for WetSep® is 40% Sulphuric Acid. The dosage of 40% sulphuric acid can be adjusted by pH monitoring system.

For detailed information on the consumption rate, please refer to the consumption chart