The dosage of DTPMPA (Diethylene Triamine Penta(Methylene Phosphonic Acid) depends on the application, water chemistry, and system conditions. Below are general guidelines for its usage in various industries:
1. Typical Dosage Recommendations
| Application | DTPMPA Concentration (ppm, active) | Notes |
|---|---|---|
| Industrial Cooling Water | 5–20 ppm | For scale/corrosion inhibition in recirculating systems. |
| Boiler Water Treatment | 2–10 ppm | Prevents CaCO₃, CaSO₄, and Fe deposits. |
| Reverse Osmosis (RO) Systems | 1–5 ppm | Controls scaling on membranes (adjust based on LSI/SDSI). |
| Oilfield Water Injection | 10–50 ppm | Inhibits barium sulfate (BaSO₄) and strontium sulfate (SrSO₄) scales. |
| Textile/Dyeing Processes | 3–15 ppm | Prevents metal ion interference and dye precipitation. |
| Pulp & Paper Industry | 5–30 ppm | Peroxide stabilizer and deposit control. |
2. Factors Influencing Dosage
- Water Hardness (Ca²⁺, Mg²⁺): Higher hardness → Increase dosage (e.g., >300 ppm CaCO₃ may need 15–30 ppm).
- pH: Works best at pH 7–9; acidic conditions (pH <6) reduce efficiency.
- Temperature: Stable up to 200°C, but higher temps may require more frequent dosing.
- Chlorine Exposure: DTPMPA is chlorine-resistant, but high oxidant levels (>5 ppm free Cl₂) may degrade it over time.
3. Example Calculation for Cooling Water
Scenario:
- System volume = 1,000 m³
- Target DTPMPA dose = 10 ppm (active)
- Product concentration = 50% active
Calculation:
Required DTPMPA (kg)=
Note: Adjust for actual product purity (e.g., 50% vs. 60%).
4. Synergistic Blends (Common Formulations)
- DTPMPA + HEDP: Enhances CaCO₃ inhibition (e.g., 1:1 ratio at 5–15 ppm total).
- DTPMPA + PAA (Polyacrylic Acid): Improves dispersion of suspended solids.
- DTPMPA + Zinc: Boosts corrosion inhibition for carbon steel.
5. Safety & Handling
- Storage: Keep in plastic (HDPE) containers; avoid contact with metals (can corrode steel).
- Personal Protection: Wear gloves/goggles (pH ~1–2 in concentrated form).
- Environmental: Low toxicity but not readily biodegradable; comply with local discharge limits.
Key Takeaway
Start with 5–10 ppm active DTPMPA for most applications, then adjust based on water tests (scale potential, corrosion rates). For precise dosing, consult a water treatment specialist or conduct pilot tests.