Sludge polymer bids are often compared in kilograms per dry tonne, yet that figure is only useful when its numerator and denominator are measured consistently. Pump settings, nominal sludge flow and a single solids sample can produce a precise-looking number that does not represent actual consumption. Agree the measurement method before a performance-linked supply decision.
Define the numerator
State whether usage means commercial product or active polymer. For liquid products, identify the density and reported content basis used in any conversion. Include product consumed during preparation, start-up or discarded solution if those quantities belong to the agreed accounting period. Do not compare a theoretical dosing setpoint with another bidder's reconciled stock consumption.
Ask Xinqi's polymer supply team for the offered grade's relevant product information. Use polymer supplier references to develop questions, but preserve the actual quoted specification and delivery records in the commercial comparison.
Measure the solids consistently
Dry-solids load depends on feed quantity and measured solids concentration over the same period. Choose sampling that represents changing feed rather than only a convenient steady interval. Record laboratory method, timing and any missing data. Where a simplified density assumption is used, label it and assess whether it is adequate for the decision.
Keep incoming dry solids distinct from dry solids captured in cake. The appropriate denominator depends on the agreed evaluation method. Switching between them can make a weak-capture run appear better or worse without any change in chemical use.
Reconcile the trial boundary
Record opening and closing stock, deliveries and identifiable losses for the evaluation window. Compare stock drawdown with metered demand and investigate material differences. Prepared solution remaining in tanks at the start or finish can distort a short trial; define how it is treated instead of silently assigning it to one candidate.
Use the result with quality constraints
A lower product-per-dry-tonne value is not a successful purchase outcome if centrate quality, throughput or cake handling falls outside the accepted range. Present consumption together with those measurements and data uncertainty. For performance-linked pricing, agree review frequency and exception handling rather than automatically penalising a supplier for an unmeasured feed change. Retain the calculation and raw records so later invoices can be checked against the same method.
Prepare the next purchasing step
For the underlying operating checks, read Wastewater Polymer Trial Report Template for Procurement Teams. Include the relevant feed information, equipment, planned quantity and delivery location when requesting a product quotation or sample. Agree the trial scope before placing routine supply.