Purification of industrial phosphoric acid (54 %) using Fe-pillared bentonite
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- 作者：Wiem Hamza ; Chaker Chtara ; Mourad Benzina
- 刊名：Environmental Science and Pollution Research
- 出版年：2016
- 出版时间：August 2016
- 年：2016
- 卷：23
- 期：16
- 页码：15820-15831
- 全文大小：1,139 KB
- 刊物类别：Earth and Environmental Science
- 刊物主题：Environment
Environment
Atmospheric Protection, Air Quality Control and Air Pollution
Waste Water Technology, Water Pollution Control, Water Management and Aquatic Pollution
Industrial Pollution Prevention - 出版者：Springer Berlin / Heidelberg
- ISSN：1614-7499
- 卷排序：23
文摘
The current problem of excess impurities in industrial phosphoric acid (IPA) 54 % P2O5 makes phosphates industries look toward low-cost but efficient adsorbents. In the present study, iron-oxide-modified bentonite (Fe-PILB) was prepared and investigated as a possible adsorbent for the removal of organic matter (OM) like humic acid (HA), chromium (Cr(III)), and zinc (Zn(II)) from IPA aqueous solutions. These adsorbents were characterized using XRD, TEM, and BET. The adsorption of impurities is well described by the pseudo-second-order model. The results indicate that Fe-PILB has a good ability to resist co-existing anions and the low-pH condition of IPA and owns a relatively high-removal capacity of 80.42 and 25 % for OM, Cr(III), and Zn(II). The mechanism of adsorption may be described by the ligand and ion exchange that happened on the active sites. The selected order of adsorption OM > Cr3+ > Zn2+ showed the importance of the competitive phenomenon onto bentonite materials’ pore adsorption. For the adsorption of OM at the low pH of IPA, H-bond complexation was the dominant mechanism. From the adsorption of heavy metals and OM complex compounds contained in IPA 54 % on Fe-PILB, the bridging of humic acid between bentonite and heavy metals (Zn(II) or Cr(III)) is proposed as the dominant adsorption mechanism (bentonite-HA-Me). Overall, the results obtained in this study indicate Fe-pillared bentonite possesses a potential for the practical application of impurity (OM, Zn(II), and Cr(III)) removal from IPA aqueous solutions.KeywordsModified clayOrganic matterIndustrial phosphoric acidHeavy metalsCompetitive adsorption