The choice of coagulant fixes the optimum pH, the dose, the sludge volume and the acid demand. Matching the reagent to the water matrix is where coagulation feasibility are decided.
The physical chemistry behind every coagulant dose, from zeta potential to the Camp number.
DAF, clarification and chemical conditioning systems for solids and oil removal.
Dissolved air flotation for coagulated solids, fats and oils.
Choosing between ferric, aluminium and pre-hydrolysed coagulants is rarely obvious from the data sheet alone — it depends on your raw-water alkalinity, temperature, target floc and downstream process. Ferric salts work across a wide pH band and produce dense, fast-settling flocs, while alum and PACl can give clearer water at lower doses on softer, warmer waters. Pre-hydrolysed coagulants such as PACl consume far less alkalinity and perform better in cold water, but cost more per kilogram of metal. We compare candidates side by side in jar tests — balancing treated-water quality, chemical cost, sludge production and alkalinity demand — to recommend the coagulant that suits your site.
Optimum pH about 6.0 to 7.5 with minimum hydroxide solubility near pH 6.3; typical dose 20 to 150 mg/L; consumes alkalinity.
Broader operating window (pH about 4.5 to 6.0 or above 8.0); dose 30 to 200 mg/L; strong, dense flocs.
Operates across pH 5.5 to 9.0 with lower acid consumption and 30 to 60 percent less sludge than alum at equivalent removal.
Neutralise charge directly at 0.5 to 5 mg/L without sweep floc, useful as a primary or aid coagulant.
High-molecular-weight polymers bridge metal-coagulated particles into large, settleable or filterable flocs.
Correct polymer preparation and ageing are essential to develop full bridging activity.
Raw-water alkalinity, temperature and organics steer the coagulant and pH-correction strategy.
Sludge volume and reagent cost are weighed against removal in the selection.
Coagulant acid demand sets the pH-correction chemical requirement.
Reynolds & Bauhm delivers this scope as part of an integrated, single-point engagement matched to your project, programme and regulatory regime.
Our expertise spans multiple industries with sector-specific water treatment solutions.