Phosphorus (P) in Water Treatment
Quick Answer
Phosphorus (P) is a nonmetal with atomic number 15. PubChem lists its standard state as solid and its relative atomic mass as 30.97376200.
Phosphorus usually appears as orthophosphate, condensed phosphate or organic phosphorus. Removal commonly uses biological uptake or precipitation with iron, aluminium or calcium salts, followed by solids separation.
Interesting Facts
- Phosphorus was first isolated from urine in 1669—an unlikely beginning for an element now central to fertilisers.
- White phosphorus can appear to glow in air because slow oxidation emits light.
- In water, the practical concern is usually phosphate or organic phosphorus: a nutrient that can drive eutrophication, not elemental phosphorus.
Water-treatment Design Implications
An element name alone is not enough to select treatment equipment. Confirm chemical form or speciation, total and dissolved concentration, pH, alkalinity, competing ions and the product-water target. Send the water-analysis results to Watermart to identify additional testing and shortlist processes before equipment is specified.
Summary Data Sources
Phosphorus (P)
1. Basic Information
| Atomic number | 15 |
| Symbol | P |
| Atomic mass | 30.97 g/mol |
| Electron configuration | [Ne]3s² 3p³ |
2. Physical and Chemical Properties
Phosphorus is a multivalent non-metallic element belonging to the nitrogen group. In nature, phosphorus is found in several allotropic forms, with white, red, and black colors. White phosphorus is highly reactive, glows in the dark, and spontaneously combusts easily when exposed to air. Red phosphorus is more stable and commonly used in industry. In water, phosphorus is generally found in the form of phosphate (PO₄³-).
3. Presence in Water and Health Effects
Phosphorus is naturally present in water in the form of phosphate. Its concentration may increase due to human activities such as the use of phosphate fertilizers and detergents. While phosphorus is essential for the human body, excess phosphate in water can lead to eutrophication and excessive algae growth. Long-term consumption of water with high phosphate levels can potentially lead to kidney disorders and osteoporosis.
4. Water Treatment Applications and Removal Methods
Phosphorus removal from water involves several methods:
- Chemical precipitation: Using aluminum or iron salts to precipitate phosphate.
- Ion exchange: Using specialized anion exchange resins to bind phosphates.
- Adsorption: Using adsorbent media such as activated alumina.
- Biological treatment: Utilizes microorganisms to absorb phosphate.
- Membrane filtration: Technologies such as nanofiltration can remove phosphates.
The choice of method depends on the phosphate concentration, the volume of water being treated, and the desired quality standard.
5. Industrial Use in Water Treatment
In the water treatment industry, phosphorus compounds are used as:
- Corrosion inhibitors in cooling systems and boilers.
- Chelating agents to control water hardness.
- Additives in wastewater treatment to enhance biological processes.