PolyDADMAC — Cationic Coagulant

Primary uses

• Primary or supplementary coagulation in drinking water
• Industrial effluent and dissolved air flotation clarification
• Charge control and retention in paper-mill systems
• Mining process-water clarification

Applications

• Municipal drinking-water plants using organic coagulant programmes
• Food, beverage and rendering plant DAF units
• Pulp and paper machine systems
• Mine process-water circuits

Advantages

• Substantially lower sludge volume than a metal-salt-only programme
• Does not consume alkalinity or depress pH
• Effective at low dose, which reduces handling and storage volumes

Limitations to consider

• Cost per litre is higher than inorganic coagulants; the saving sits in sludge and alkalinity, so the comparison must be made on total cost
• Overdosing reverses charge and makes clarity worse, so control is less forgiving
• Viscous solution: dilution and dosing equipment need to be suited to it
• Dose is established on your own water by jar test, coupon monitoring or a controlled plant trial. Supplier literature values are starting points for that trial, not a specification.
• Many treatment chemicals are regulated in transport and have specific storage, containment and personal-protection requirements. The SDS for the exact product offered is the governing document, and it should be reviewed before the delivery is scheduled rather than after it arrives.

How to choose the right grade

• Start from a current water or effluent analysis: alkalinity, pH, turbidity, temperature and the contaminant you are actually targeting
• State whether the duty is drinking water, wastewater, industrial effluent or process-water reuse, because the certification requirement follows from it
• Say what sludge volume and disposal cost you can live with — it often decides between inorganic and organic chemistry
• Confirm the coldest water temperature the plant sees, since winter performance in Canada is the real design case
• Confirm what dosing, make-down and storage equipment already exists before changing product family
• Coagulant and flocculant selection is decided by a jar test on your own water, not by a product name. Two plants treating water that looks identical on paper often land on different chemistry and very different doses.
• Exact specification is confirmed against supplier documentation at quotation.

Typical grades

• Low, medium and high molecular-weight bands as the supplier defines them
• Industrial grade
• Drinking-water grade where the supplier holds the certification
• Solution strength and active content are per-offer values, and they change the dose and the true cost per unit of water treated. Compare quotations on active content delivered, not on price per litre or per kilogram, and read the value from the supplier documentation for the exact product offered.
• Drinking-water and food-contact applications require certification held for the specific product and manufacturing site. Whether the product offered carries it is confirmed against supplier documentation at quotation and is never presented here as a held approval.