
介紹
In some areas, fluoride levels in groundwater or industrial wastewater may exceed safe limits. Excessive fluoride not only affects drinking water quality but can also harm human health, leading to dental fluorosis, bone problems, and other issues. Therefore, effective fluoride removal during water treatment is crucial. Activated carbon, with its well-developed structure and outstanding adsorption properties, has certain application value in fluoride control and can be combined with other processes to improve treatment efficiency.
Why can activated carbon work for fluoride?
Activated carbon’s ability to adsorb fluoride in water primarily stems from its abundant microporous structure. Conventional activated carbon adsorbs fluoride ions mainly through physical adsorption and weak chemisorption. However, specially modified activated carbon (such as iron-modified or aluminum-modified activated carbon) can further enhance its affinity for fluoride, thus significantly increasing its adsorption capacity. Its advantages include structural stability, moderate cost, minimal impact on water quality, and suitability for various types of water sources.
| Activated Carbon Type | Surface Area (m²/g) | 碘值(毫克/克) | Fluoride Adsorption Capacity (mg F⁻/g) | Loading (Al₂O₃ or Fe₂O₃) | 粒徑 |
| Aluminum Activated Carbon (Al-AC) | 700–1100 | 800–1000 | 1.5–3.5 | Al₂O₃: 3–12% | 0.5–2 mm |
| Iron Activated Carbon (Fe-AC) | 600–900 | 700–950 | 1.8–4.0 | Fe₂O₃: 5–15% | 0.5–2 mm |
| 粉狀活性碳 | 900–1300 | 900–1100 | 0.5–1.5 | None | ≥90% passing 325 mesh |
In practical applications, activated carbon can be used alone to treat slightly fluoride-containing water; for water bodies with higher fluoride concentrations, it is more suitable to use it in combination with technologies such as coagulation sedimentation, reverse osmosis, and ion exchange to achieve better results.
Applications of Activated Carbon in Defluoridation Processes
In engineering, activated carbon defluoridation is commonly implemented in two ways. One is by adding powdered activated carbon, allowing it to fully contact the water before separation through filtration or sedimentation. This method is suitable for intermittent treatment or small-scale applications. The other is by using granular activated carbon packed into a fixed bed, allowing water to continuously flow through the adsorption layer. This method is more common in drinking water treatment plants, rural water supply points, and industrial wastewater treatment.
Different types of activated carbon need to be selected based on the actual water quality. For example, aluminum-modified activated carbon can enhance adsorption by forming complexes with fluoride ions through surface hydroxyl groups; iron-modified activated carbon reduces the fluoride content in the water by forming stable compounds with fluoride through surface iron oxides.
結論
Activated carbon, as a highly efficient, stable, and easy-to-use water treatment material, shows promising application prospects in removing fluoride from water. Whether in simple household water purifiers or large-scale drinking water treatment systems, activated carbon provides reliable auxiliary fluoride removal capabilities. With the development of modification technology, the selectivity and adsorption capacity of activated carbon for fluoride continue to improve, playing an even more important role in ensuring water quality safety.
If necessary, we can also provide you with suitable activated carbon parameters and selection suggestions for fluoride removal.