The optimal dosage of PASP in water treatment depends on factors such as water hardness, pH, temperature, and specific application. Below are the recommended dosage ranges for different water treatment applications:
1. Industrial Cooling Water Systems
- Dosage: 5–15 mg/L
- Purpose: Prevents scaling and corrosion in cooling towers and heat exchangers.
- Factors affecting dosage: Higher hardness and alkalinity require higher concentrations.
2. Boiler Water Treatment
- Dosage: 10–30 mg/L
- Purpose: Reduces scaling from calcium carbonate (CaCO₃), calcium sulfate (CaSO₄), and iron oxides.
- Factors affecting dosage: Boiler pressure and feedwater quality influence the required concentration.
3. Reverse Osmosis (RO) & Desalination Systems
- Dosage: 1–10 mg/L
- Purpose: Prevents membrane scaling and extends RO membrane lifespan.
- Factors affecting dosage: TDS level, scaling tendency, and compatibility with other antiscalants.
4. Oilfield Water Injection Systems
- Dosage: 10–50 mg/L
- Purpose: Prevents scale and corrosion in pipelines and downhole equipment.
- Factors affecting dosage: Water salinity, pressure, and scaling potential.
5. Agricultural Irrigation Systems
- Dosage: 5–20 mg/L
- Purpose: Prevents clogging in drip irrigation and sprinkler systems due to calcium and magnesium deposits.
- Factors affecting dosage: Water hardness and pH levels.
6. Textile & Dyeing Industry
- Dosage: 10–30 mg/L
- Purpose: Improves dyeing efficiency by controlling metal ion interference and preventing scale formation.
- Factors affecting dosage: Dye composition and water chemistry.
7. Detergents & Cleaning Agents
- Dosage: 0.5–5 mg/L
- Purpose: Acts as a biodegradable chelating agent, reducing water hardness without using phosphates.
- Factors affecting dosage: Water hardness and detergent formulation.
Key Considerations for Optimal PASP Dosage
- Water hardness: Higher hardness requires a higher PASP concentration.
- pH level: PASP remains effective in a wide pH range (5–10), but performance may vary.
- Synergistic effects: PASP can be combined with phosphonates (HEDP, ATMP) or polymer dispersants for improved performance.
- Overdosing risks: Excessive PASP may cause foaming or interfere with other treatment chemicals.