Water treatment chemicals: Production route
Four product families that settle, protect and disinfect water
What this tab covers How it is made: the main production routes or, for product families, the main product types and technologies, compared on share of supply, inputs per tonne, plant scale, yield, co-products and unit cost.This is a family of four product groups rather than one process. Inorganic coagulants are simple acid-metal reactions done in small plants close to customers, because the product is mostly water. Organic flocculants, mainly polyacrylamide, are a scale business tied to acrylonitrile. Corrosion and scale inhibitors are formulated blends of phosphonates and polymers, sold with service. Biocides and disinfectants run from bulk chlorine and hypochlorite to specialty non-oxidising biocides. Margins rise from coagulants (commodity, tendered) to service programmes (inhibitors, biocides), which is why the large players bundle chemistry, equipment and monitoring.
Routes compared
| Route | Share of supply | Inputs per tonne | Typical scale | Yield | Co-products | Unit cost |
|---|---|---|---|---|---|---|
| Inorganic coagulants: alum, poly-aluminium chloride (PAC), ferric chloride and ferric sulphate | part of coagulants and flocculants, 36.3% of market value (IMARC 2025); split between inorganic and organic not published | indicative: about 0.15-0.3 t aluminium trihydrate and 0.3-0.7 t of 32% HCl per t of liquid PAC (10-18% Al2O3, 40-50% basicity); stoichiometry-based | small to medium liquid plants, often 20-150 kt/yr, sited within a few hundred km of customers (indicative) | near-complete conversion of metal (acid-metal reaction) | few; ferric chloride often uses waste HCl or TiO2 by-product chlorides | not published; raw materials and freight dominate (indicative) |
| Organic polymers: polyacrylamide (anionic, cationic, non-ionic), polyDADMAC, polyamines | part of the 36.3% coagulant and flocculant group (IMARC 2025); SNF is the largest producer (company statements, indicative) | about 0.75 t acrylonitrile per t acrylamide (stoichiometric, 53/71); plus comonomers | world-scale plants of 50-200 kt/yr (indicative) | over 99% acrylonitrile conversion in enzymatic hydration (indicative) | minimal | tracks acrylonitrile and propylene; not published |
| Corrosion and scale inhibitors | 21.6% of market value (IMARC 2025); scale inhibitors fastest-growing type at 4.6% a year (MarketsandMarkets) | not published (formulated blends, typically 20-50% active, indicative) | blending plants of a few kt/yr; actives from larger phosphonate and acrylic plants | not applicable (blending) | none | not published; price is set by programme value, not raw material |
| Biocides and disinfectants | 16.8% of market value (IMARC 2025) | hypochlorite: about 0.12 t chlorine and 0.14 t caustic soda per t of 12.5% solution (stoichiometric); specialties not published | hypochlorite made at chlor-alkali sites or on site; specialties in multi-purpose plants | not applicable | disinfection by-products (trihalomethanes) formed in water | not published |
| Other: pH adjusters, antifoams, chelants, membrane cleaners, oxygen scavengers | remaining 25.3% of market value (derived from IMARC 2025 shares) | commodity chemicals | varies | not applicable | none | commodity prices |
How each route works
Inorganic coagulants: alum, poly-aluminium chloride (PAC), ferric chloride and ferric sulphateAluminium trihydrate or bauxite is dissolved in sulphuric acid (alum) or hydrochloric acid (PAC, partly neutralised to raise basicity). Ferric chloride is made by chlorinating iron or pickle liquor, and is also a by-product of chloride-route titanium dioxide. Dosed into raw water to destabilise particles, and into sewage to precipitate phosphorus.
Cheap and robust; adds sludge and dissolved salts; aluminium residuals are regulated in drinking water.
IMARC 2025; chlorine and hydrochloric acid tiles; Kemira AGM 2025 Organic polymers: polyacrylamide (anionic, cationic, non-ionic), polyDADMAC, polyaminesAcrylonitrile is hydrated, now usually with an enzyme catalyst, to acrylamide. Acrylamide is copolymerised with charged monomers into very long chains sold as powder or emulsion. A few ppm bridges small flocs into large ones and dewaters sludge. The same polymers serve paper, mining tailings and enhanced oil recovery.
Very effective at low dose; acrylamide monomer is toxic and a residual limit applies; polymers are not readily biodegradable.
acrylonitrile tile (16% of ACN to acrylamide); EU Drinking Water Directive 2020/2184 Corrosion and scale inhibitorsBlends of phosphonates (HEDP, ATMP), polyacrylates and copolymers, azoles for copper, and zinc or molybdate salts. They keep calcium carbonate and silica in solution and form protective films. Sold as programmes for cooling towers, boilers, reverse osmosis membranes and oil production.
High margin and sticky contracts; phosphorus discharge limits push a shift to phosphorus-free polymers.
IMARC 2025; MarketsandMarkets 2025; acrylic acid tile Biocides and disinfectantsOxidising biocides (chlorine, sodium hypochlorite, chlorine dioxide, bromine, hydrogen peroxide, ozone) kill bacteria in drinking water and cooling towers. Non-oxidising biocides (isothiazolinones, glutaraldehyde, DBNPA, quats) treat industrial systems and pipelines where oxidants would corrode or react.
Chlorine is cheapest; specialty biocides carry registration costs under EU BPR and US FIFRA, which protects incumbents.
IMARC 2025; chlorine and caustic soda tiles Other: pH adjusters, antifoams, chelants, membrane cleaners, oxygen scavengersCaustic soda, lime, sulphuric acid and CO2 adjust pH; sulphite or hydrazine replacements scavenge oxygen in boilers; EDTA and citric acid clean membranes; silicone and polyether antifoams control foam in aeration basins.
Low margin; bought with the main programme.
derived from IMARC 2025 Unit economics are indicative ranges from the sources named; costs move with feedstock and energy prices, plant size and region.