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过程工程学报 ›› 2020, Vol. 20 ›› Issue (11): 1281-1288.DOI: 10.12034/j.issn.1009-606X.219382

• 反应与分离 • 上一篇    下一篇

不同粒径改性粉煤灰对磷酸根吸附性能的影响

杨建林1， 张宇鳌1,2， 马淑花2*， 王晓辉2   

  1. 1. 辽宁工程技术大学材料科学与工程学院，辽宁 阜新 123000 2. 中国科学院过程工程研究所湿法冶金清洁生产技术国家工程实验室，北京 100190
  • 收稿日期:2019-12-24 修回日期:2020-02-23 出版日期:2020-11-22 发布日期:2020-11-20
  • 通讯作者: 马淑花 shma@ipe.ac.cn
  • 基金资助:
    内蒙古自治区科技重大专项（粉煤灰基土壤调理剂制备及应用示范）

Effect of different particle sizes of modified fly ash on phosphate adsorption performance

Jianlin YANG1, Yu'ao ZHANG1,2, Shuhua MA2*, Xiaohui WANG2   

  1. 1. College of Materials Science and Engineering, Liaoning Technical University, Fuxin, Liaoning 123000, China 2. National Engineering Laboratory for Hydrometallurgical Cleaner Production Technology, Institute of Process Engineering, Chinese Academy of Sciences, Beijing 100190, China
  • Received:2019-12-24 Revised:2020-02-23 Online:2020-11-22 Published:2020-11-20

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摘要： 废水排放过量的磷导致水体污染日益严重，将粉煤灰通过化学改性制备成了水化硅酸钙吸附剂，研究了改性吸附剂对磷酸根的吸附效果。利用XRD, SEM及BET比表面积等手段对粒度分级前后的吸附剂进行表征，研究不同粒级吸附剂对磷酸根的吸附性能，并考察其吸附机理。结果表明，不同粒级的吸附剂其化学成分出现了明显的偏析现象，孔隙结构也差异显著。相比其他粒径下的吸附剂颗粒，颗粒粒径在50?75 μm时，吸附剂中钙和硅含量较多，铝、铁和镁含量较低，水化硅酸钙组分含量最高，且伴有含铝的托贝莫来石晶体出现，钙离子的增加使其可以与更多的磷酸根结合形成沉淀。同时此粒径下具有较高的比表面积及孔隙度，疏松多孔的结构为钙离子提供更多活性位点。当使用粒径在50?75 μm的吸附剂吸附磷酸根时，磷的饱和吸附量可达到17.1 mg/g，比未分级的吸附剂高19.58%。

关键词: 粉煤灰, 水化硅酸钙, 磷酸根, 不同粒径, 饱和吸附量

Abstract: Excessive discharge of phosphorus in wastewater leads to increasingly serious water pollution. The fly ash was chemically modified into a hydrated calcium silicate adsorbent to explore its absorption effect on the phosphate. XRD, SEM, BET specific surface area and so on were used to characterize the adsorbents before and after particle size classification. Then the adsorption performance of the adsorbents with different particle sizes on phosphate was studied, and the adsorption mechanism was also investigated. The results showed that the chemical compositions of the adsorbents with different particle sizes showed significant segregation, and the pore structures were also significantly different. Specifically, compared to other adsorbent particles, the particles with the size of 50?75 μm had a higher content of calcium and silicon, lower content of aluminum, iron, and magnesium and thereof higher content of hydrated calcium silicate companied with aluminum-containing tobermullite crystals. The increase of calcium ions made it easy to combine with more phosphate to form a precipitate. At the same time, this particle had a higher specific surface area and more porosity and the loose and porous structure provided more active sites for calcium ions. When used as an adsorbent to adsorb phosphate, the saturated phosphorus adsorption capacity of the particles with the size of 50?75 μm can reach 17.1 mg/g, which was 19.58% higher than that of an unclassified adsorbent.

Key words: fly ash, hydrated calcium silicate, phosphate, different particle sizes, saturated adsorption capacity