# Water treatment chemicals: Emissions

Why a polymer weighs far more on the climate than alum

Source page: https://www.materialinsights.org/chemicals/water_treatment/emissions/

What this tab covers The greenhouse-gas footprint per tonne, split by lifecycle phase (feedstock, production, movement, use, end of life), the global total, other environmental impacts, levers and low-carbon routes, India's position, and where the investment opportunity lies. Emission intensity 1.00 t CO2e per t range 0.3-4.8 (iron sulphate 0.29, alum 0.79, 40% ferric chloride 1.44, polyacrylamide about 4.8) · indicative family value weighted towards coagulants, which dominate tonnage; per-product factors from AusLCI and Carbonfact

Per t of product, cradle-to-gate. Intensity: Tushar et al., Water 18, 472 (2026), Table 4; Carbonfact polyacrylamide average 4.76 kg CO2e/kg (indicative). Global total: not published.

#### Share of footprint by lifecycle phase
 Feedstock 60% Production / process 30% Movement 10%

#### Footprint by lifecycle phase

| Phase | Intensity | Share | Main sources of emissions | Notes | Source |
|---|---|---|---|---|---|
| **Feedstock** | about 0.6 t CO2e per t (indicative) | 60% | acrylonitrile (propylene and ammonia), chlor-alkali electricity behind HCl and chlorine, alumina refining | polymers are far more carbon-intensive per tonne than coagulants | indicative, based on per-product factors above |
| **Production / process** | about 0.3 t CO2e per t (indicative) | 30% | heat for dissolution and polymer drying; electricity | powder polymer drying is energy-intensive | indicative |
| **Movement** | about 0.1 t CO2e per t (indicative) | 10% | road haulage of liquid products that are mostly water | transport was about 1.5% of an Australian treatment plant's footprint, where electricity was 59% and ferric chloride 31% | Tushar et al. 2026 |
| **Use** | not applicable as direct emissions | – | chemicals are consumed in water; the larger footprint is treatment-plant electricity | chemicals were about 39% of one industrial plant's CO2e per m3 (Tushar et al. 2026) | Tushar et al. 2026 |
| **End of life** | not published | – | coagulant and polymer end up in sludge that is landfilled, incinerated or spread on land | polymer carbon is released if sludge is incinerated | indicative |

#### Other environmental impacts

Aluminium and acrylamide residuals in drinking water; disinfection by-products; phosphonate and biocide discharge to rivers; added salinity in treated water; extra sludge volume.

#### Levers to cut emissions

- Dose optimisation with online sensors and digital dosing, which can cut chemical use (savings vary by site, not published)
- Coagulants from waste acids and by-product iron chloride (TiO2, steel pickling) instead of virgin inputs
- Bio-based flocculants and coagulants (tannins, starch, chitosan); Kemira's renewable solutions revenue was EUR 240 million in 2024 with a target over EUR 500 million by 2030 (Kemira AGM 2025)
- Renewable power for chlor-alkali and polymer plants; Kemira targets a 51.23% cut in scope 1 and 2 emissions by 2030 from 2018 (Kemira AGM 2025)

#### India

India's footprint is not published. Growth in reuse and zero liquid discharge will raise chemical and power use per m3; domestic coagulants from chlor-alkali by-product HCl are lower-carbon than imported polymers (indicative).
 Emission figures are indicative global averages from the life-cycle studies named; actual footprints vary widely by site, energy mix and method.

#### Low-carbon routes

| Route | Intensity | Cost premium | Status | Source |
|---|---|---|---|---|
| **Bio-based polymers and coagulants (tannin, starch and chitosan derivatives)** | not published | not published; generally higher than polyacrylamide (indicative) | commercial in niche uses; Kemira renewable solutions EUR 240 million revenue (2024) | Kemira AGM 2025 |
| **On-site electrochlorination and electrochemical peroxide** | depends on grid | not published | commercial for disinfection at plant scale | hydrogen peroxide tile (indicative) |

 For a climate investor The decarbonisation is small per tonne, but the family enables water reuse, which saves energy and freshwater at scale. The investable gaps are industrial water services in India (Ion Exchange, Thermax, Kemira's move into services), bio-based flocculants, PFAS removal, and digital dosing that lowers chemical use. What has to be true: utilities and industry pay for performance rather than lowest tender price, and pollution boards enforce discharge norms.

## Other sections

- [Summary](https://www.materialinsights.org/chemicals/water_treatment/index.md)
- [Overview](https://www.materialinsights.org/chemicals/water_treatment/overview/index.md)
- [Correlation](https://www.materialinsights.org/chemicals/water_treatment/correlation/index.md)
- [Production route](https://www.materialinsights.org/chemicals/water_treatment/routes/index.md)
- [Production](https://www.materialinsights.org/chemicals/water_treatment/production/index.md)
- [Feedstocks](https://www.materialinsights.org/chemicals/water_treatment/feedstocks/index.md)
- [Cycles](https://www.materialinsights.org/chemicals/water_treatment/cycles/index.md)
- [Trading](https://www.materialinsights.org/chemicals/water_treatment/trading/index.md)
- [Movement](https://www.materialinsights.org/chemicals/water_treatment/movement/index.md)
- [Regulation](https://www.materialinsights.org/chemicals/water_treatment/regulation/index.md)
- [Characteristics](https://www.materialinsights.org/chemicals/water_treatment/characteristics/index.md)
- [Relationships](https://www.materialinsights.org/chemicals/water_treatment/links/index.md)