PACHS
Al₂(OH)ₙCl₆₋ₙ·SO₄
Polyaluminium chloride hydroxide sulphate (PACHS) is a sulphate-modified polyaluminium coagulant supplied as a pale-yellow liquid with 8-10% Al₂O₃. The added sulphate promotes larger, faster-settling flocs, making the product suited to enhanced coagulation and demanding industrial wastewater duties as well as comprehensive water treatment. CHIMI ART manufactures PACHS in Egypt and supplies it in drums, IBCs or bulk flexitanks with a certificate of analysis.
Product Overview
Polyaluminium chloride hydroxide sulphate (PACHS) is a sulphate-modified polyaluminium coagulant supplied as a pale-yellow liquid with 8-10% Al₂O₃. The added sulphate promotes larger, faster-settling flocs, making the product suited to enhanced coagulation and demanding industrial wastewater duties as well as comprehensive water treatment. CHIMI ART manufactures PACHS in Egypt and supplies it in drums, IBCs or bulk flexitanks with a certificate of analysis.
Technical Specifications
- Chemical Formula
- Al₂(OH)ₙCl₆₋ₙ·SO₄
- Appearance
- Pale yellow liquid
- Concentration
- 8-10% Al₂O₃
- Specific Gravity
- 1.15-1.20
- pH Range
- 3.0-4.5
- Solubility
- Fully miscible with water
- Available Packaging
- 200L drums · 1000L IBC · Bulk flexitank
- Shelf Life
- 12 months
- Storage Conditions
- Polyethylene containers
| Property | Value |
|---|---|
| Chemical Formula | Al₂(OH)ₙCl₆₋ₙ·SO₄ |
| Appearance | Pale yellow liquid |
| Concentration | 8-10% Al₂O₃ |
| Specific Gravity | 1.15-1.20 |
| pH Range | 3.0-4.5 |
| Solubility | Fully miscible with water |
| Available Packaging | 200L drums · 1000L IBC · Bulk flexitank |
| Shelf Life | 12 months |
| Storage Conditions | Polyethylene containers |
Applications
Dosing Guidelines
Dose rates for PACHS are similar to those of standard PAC on comparable duties, and the hybrid formulation may allow a reduced dose relative to conventional coagulants — but the correct figure is always established empirically. Run jar tests across a range of doses and coagulation pH values, scoring floc formation speed, settled turbidity and sludge volume, then confirm the chosen operating point in a plant trial. Feed the liquid neat or diluted with a chemical-resistant metering pump at a point of good mixing, and re-optimise when the influent changes.
How It Works
PACHS carries the same highly charged, pre-hydrolysed polynuclear aluminium species as conventional polyaluminium chloride, so it destabilises colloids by adsorbing onto their negatively charged surfaces and neutralising the repulsion that keeps them dispersed. The distinguishing feature is the incorporated sulphate: sulphate ions promote aggregation and polymerisation of the aluminium hydrolysis products, encouraging the growth of larger, denser flocs that settle faster and resist shear. This combination of strong charge neutralisation, particle bridging and sweep flocculation gives the hybrid coagulant a broad effective pH window and robust performance on difficult waters — high organic loads, variable turbidity and mixed industrial effluents. As with any coagulant, alkalinity consumption and residual aluminium should be tracked, and the working dose confirmed by jar testing on the actual water.
Usage Tips
Store PACHS in polyethylene, FRP or other non-metallic tanks, in closed containers away from direct sunlight; shelf life is 12 months. Avoid carbon steel, aluminium and galvanised fittings anywhere in the storage and dosing line, as the acidic solution corrodes them. Protect the product from freezing and mix gently before use after a long standstill. Wear gloves and eye protection when handling, provide containment around tanks and dosing skids, and rinse any splashes promptly with water.
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Frequently Asked Questions
What does the 'HS' in PACHS stand for?
PACHS is short for polyaluminium chloride hydroxide sulphate: a polyaluminium chloride coagulant whose structure incorporates hydroxide and sulphate groups. It is a hybrid grade rather than a simple PAC solution, formulated so the sulphate component reinforces floc growth. Full specifications are stated in the current Technical Data Sheet, available on request.
How does PACHS perform differently from conventional PAC?
The chemistry of charge neutralisation is the same, but the incorporated sulphate promotes aggregation of the aluminium hydrolysis products, typically giving larger, denser flocs that settle faster, along with a broad effective pH window. Whether that translates into a lower dose or better clarity on your water is established by running jar tests side by side with your current coagulant.
Is PACHS suitable for variable industrial wastewater?
Yes — enhanced coagulation of difficult and variable effluents is the product's core duty, alongside comprehensive treatment of municipal and industrial waters. Because industrial effluents differ widely in organic load, pH and solids, a staged approach works best: jar testing across the expected range of influent conditions, then a supervised plant trial before committing to a permanent dosing regime.
How should I benchmark PACHS against my current coagulant?
Run parallel jar tests on the same water at an equal dose basis (expressed as Al₂O₃ for aluminium products), comparing settled turbidity, floc formation speed, pH depression and sludge volume. Repeat at the extremes of your seasonal water quality, then confirm the winner in a plant trial. CHIMI ART's technical team can support the protocol and interpret results.
In what quantities is PACHS supplied?
PACHS ships as a liquid in 200 L drums, 1,000 L IBC totes, and bulk flexitanks for container-scale volumes. Shelf life is 12 months in closed polyethylene containers away from direct sunlight. A certificate of analysis accompanies every delivery, and the Technical and Safety Data Sheets are available from the product page or on request.
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