Paper Mill Wastewater: Decolorant, PAC and PAM Jar Test

Direct answer

For colored paper-mill wastewater, screen decolorant, PAC and PAM on a sample taken from the intended dosing point. The video shows staged chemical addition, floc formation and liquid-solid separation in a beaker. Selection should use the mill's furnish, pulping or recycled-fiber source, pH, suspended solids, measured color and downstream biological or reuse requirements.

Locate the source before choosing chemicals

Paper-machine white water, deinking streams, pulping liquor carryover and combined final effluent present different color and solids. Identify the sample point and whether fiber recovery, dissolved-air flotation, primary clarification or biological treatment comes next. That prevents a jar test from solving the wrong part of the mill circuit.

Use a composite sample when production grade or recycled furnish changes during the day. Record temperature and pH because both can alter coagulation and polymer response.

Screen the three roles independently

The linked Water Decoloring Agent is evaluated for color response, PAC for colloid destabilization, and PAM for bridging and separation. Compare single-product controls before assuming that the full sequence is needed.

For a useful plant decision, measure the site's color metric and suspended solids, then observe recovered-fiber quality, sludge behavior and effects on the next treatment step. Keep the selected grade identifiers with the result.

Transfer the beaker result

Document sample source and date, starting values, pH adjustment, product grade and batch, dose order, mixing, separation time and measured endpoints. Scale up through a controlled plant trial with operating staff watching chemical feed, carryover and sludge handling.

Protect the paper process during scale-up

Clarify whether the selected chemicals will contact recovered fiber, broke, white-water loops or only final effluent. A condition that improves primary clarification may affect fiber loss, drainage, charge balance or biological loading if it is applied at a different point. Include paper-production and wastewater operators in the trial plan.

Start with a defined flow and observation period. Track chemical feed, inlet variability, clarified-water measurements, recovered solids and sludge dewatering. Keep the previous program available within the site's change-control procedure. At the end, reconcile the operational result with the jar-test record and update the grade, sequence or feed point before purchasing a full campaign quantity.

Document the furnish and paper grade made during the trial. That production context is essential when comparing the same program on a later shift or machine campaign. Record wet-end additive changes that may alter charge or solids carryover. Keep operator comments and laboratory results together in the final trial review so the next campaign can use the same basis.

Technical specifications

Use these source-linked fields when preparing the sample request, specification or order record.

Paper-mill sample points need different tests

The sample source determines which outcome matters and which products deserve screening.