PAC vs ACH for Water Treatment | Beta Pramesti Asia

PAC and Aluminium Chlorohydrate (ACH) are both aluminium coagulants, but neither is a universal winner. Buyers should compare the actual grades at equivalent product and active dose, then evaluate pH/alkalinity, treated-water quality, floc, separation, sludge, influent stability, and total cost through jar testing and a controlled plant trial.

PT Beta Pramesti Asia, through beta.co.id, supplies PAC and ACH for industrial water and wastewater evaluation in Indonesia. Selection must use the correct product and lot documents, not the assumption that every PAC or every ACH has the same composition.

Technically reviewed: 31 July 2026.

Which PAC-versus-ACH differences matter to a plant?

PAC is a family of liquid or solid polyaluminium chloride grades with varying active content, basicity, density, pH, and impurities. ACH is a high-basicity aluminium coagulant, but its specification and process response also depend on grade. A chemical family name does not replace the TDS, CoA, SDS, and application test.

Comparison dimension	PAC	ACH	Decision evidence
Supplied form	Liquid or solid, depending on grade	Commonly supplied as a liquid grade in Beta’s water-treatment range	TDS, CoA, packaging, storage, and make-down capability
Active content/basicity	Varies by grade	Commonly higher, but the grade document governs	Al₂O₃ normalisation and verified test method
pH/alkalinity effect	Depends on dose, grade, and water	Depends on dose, grade, and water	Before/after pH and alkalinity across the dose sweep
Floc formation/separation	Affected by mixing, temperature, particles, and the unit	Affected by the same variables	Floc size/strength, settling or DAF, carryover, and filtration
Residuals and sludge	Cannot be predicted from the chemical name	Cannot be predicted from the chemical name	Required residual parameter, sludge volume/solids, and dewatering
Cost	Product, freight, storage, make-down, dosing, pH correction, and sludge	Use the same cost basis	Total cost per m³ meeting every target

Indonesia’s SNI 3822:2018 for Polyaluminium Chloride is listed as current for PAC quality requirements and test methods in the stated uses. A product standard does not establish that one PAC or ACH will outperform the other at a specific plant.

How can dose be compared fairly?

Put both products on the same basis. Active Al₂O₃ dose (mg/L) = product dose (mg/L) × Al₂O₃ mass fraction. Arithmetic example: 10 mg/L of a product containing 30% Al₂O₃ equals 3 mg/L Al₂O₃. This is not a dose recommendation and does not equalise basicity, speciation, impurities, or performance.

Stage	Minimum control
Define the target	Influent, treated-water limits, pH limit, residual, sludge, unit capacity, and cost
Verify the product	Grade, lot, Al₂O₃, basicity, density, pH, impurities, TDS/SDS/CoA, and storage condition
Run jar tests	Same sample and mixing, blank/reference, dose sweep on product and active basis, and complete measurement
Select candidates	A candidate must pass treated water, floc/separation, pH, sludge, safety, and cost gates
Run a plant trial	Calibrate the pump, change one primary variable, record batch/flow/dose, and apply acceptance criteria
Approve change control	Set purchase specification, incoming check, retention sample, alarms, and re-trial triggers

Which data belongs in the jar test?

Use samples representing the source, shift, season, or batch discharge that makes operation difficult. Record flow, pH, alkalinity, temperature, turbidity/TSS, colour, organics or another target, ionic strength where relevant, and supporting chemicals. Keep rapid mix, slow mix, time, and evaluation method consistent.

PAC or ACH cannot automatically correct free oil, dissolved salts, biological load, failed rapid mixing, clarifier overloading, or damaged filters. Separate a process fault from a coagulant-selection problem before increasing the dose.

See industrial liquid PAC, custom PAC trial qualification, and ACH for water treatment for product detail. Select any supporting polymer separately through the industrial flocculant range, with its own dose sweep and compatibility review.

PAC vs ACH FAQs

Does ACH always require a lower dose than PAC?

No. Product and active dose depend on grade, water, pH/alkalinity, mixing, target, and separation unit. Compare them on the same basis and use total cost per cubic metre meeting every limit.

Is the highest basicity always best?

No. Basicity is important but is not a standalone performance score. Speciation, active content, impurities, temperature, particles, organic matter, dose basis, and process conditions also affect the result.

How can a buyer request a recommendation?

Send water analysis, flow and variation, quality targets, process diagram, current product/dose, jar-test results, pump and mixing data, sludge, and cost limits through the PT Beta Pramesti Asia contact page.