Removal of phosphate species from solution by adsorption onto calcite used as natural adsorbent

详细信息	查看全文 | 推荐本文 |

• 作者：Kostantinos Karageorgiou ; Maximos Paschalis ; Georgios N. Anastassakis
• 关键词：Environment ; Liquid effluents purification ; Adsorption ; Orthophosphates adsorption ; Adsorbents ; Calcite ; Phosphates
• 刊名：Journal of Hazardous Materials
• 出版年：2007
• 期刊代码：50_03043894
• 类别：ce
• 出版时间：31 January 2007
• 卷：139
• 期：3
• 页码：447-452
• 文件大小：515 K

摘要

Phosphates are very important basic materials in agricultural and other industrial applications. Phosphorus is often present in low concentrations in wastewater, almost solely in the form of organic and inorganic phosphates (ortho- and poly-phosphates). The removal of phosphates from surface waters is generally necessary to avoid problems, such as eutrophication, particularly near urban areas. The usual methods of treatment are either biological or physicochemical by sedimentation. This paper studies the removal of phosphate species by adsorption onto calcite used as natural adsorbent.

The phosphate solutions were prepared artificially by adding certain quantities of K₂HPO₄ in water. The effect of equilibrium pH, phosphate/mineral ratio and contact time was studied. The results showed that pH plays an important role in the removal of phosphate species from solution, with removal being more efficient in the basic pH region. The experimental results also show that adsorption is also efficient for high ratios phosphate/adsorbent. Finally, the adsorption process is time dependant. Based on the experimental results a possible mechanism of phosphate removal onto calcite surface is proposed.

As a general conclusion, phosphate species seem to be efficiently removed from solutions using calcite as natural adsorbent. In addition, the adsorption product can be used as fertilizer for acid soils.