工业水处理 ›› 2023, Vol. 43 ›› Issue (2): 82-88. doi: 10.19965/j.cnki.iwt.2022-0293

• 试验研究 • 上一篇    下一篇

黄钾铁矾对Mo(Ⅵ)的吸附行为和机理研究

陈波1,2(), 梁朝丽1, 王锋1,2, 蔡平雄1,2()   

  1. 1.北部湾大学石油与化工学院, 广西 钦州 535000
    2.广西绿色化工新材料与安全技术重点实验室, 广西 钦州 535000
  • 收稿日期:2022-11-09 出版日期:2023-02-20 发布日期:2023-05-26
  • 通讯作者: 蔡平雄 E-mail:cbo-11@163.com;pingxiongcai@bbg.edu.cn
  • 作者简介:陈波(1985— ),博士,副教授。E-mail:cbo-11@163.com
    蔡平雄,博士,教授级高工。E-mail:pingxiongcai@bbg.edu.cn
  • 基金资助:
    广西自然科学基金项目(2020GXNSFBA297128);广西科技基地和人才专项(桂科AD20238041);广西自然科学基金联合培育项目(2019GXNSFAA245016)

Adsorption behavior and mechanism of jarosite for Mo(Ⅵ)

Bo CHEN1,2(), Chaoli LIANG1, Feng WANG1,2, Pingxiong CAI1,2()   

  1. 1.College of Petroleum and Chemical Engineering, Beibu Gulf University, Qinzhou 535000, China
    2.Guangxi Key Laboratory of Green Chemical Materials and Safety Technology, Qinzhou 535000, China
  • Received:2022-11-09 Online:2023-02-20 Published:2023-05-26
  • Contact: Pingxiong CAI E-mail:cbo-11@163.com;pingxiongcai@bbg.edu.cn

摘要:

钼广泛分布于天然矿山中,且主要以钼酸盐〔Mo(Ⅵ)〕的形式存在。钼资源的快速消耗,可能会增加含钼工业废水的排放并引起严重的环境问题。采用水热法合成黄钾铁矾矿物并用于去除模拟废水中的Mo(Ⅵ),利用XRD表征了矿物材料的理化性质,基于静态吸附实验研究了吸附时间、Mo(Ⅵ)初始浓度、初始pH、吸附剂投加量和不同共存离子对黄钾铁矾吸附Mo(Ⅵ)行为的影响,并结合黄钾铁矾吸附Mo(Ⅵ)前后FT-IR官能团变化结果,揭示黄钾铁矾对Mo(Ⅵ)的吸附动力学特征和吸附机理。结果表明:黄钾铁矾对Mo(Ⅵ)的吸附过程符合准二级动力学模型和Langmuir模型,吸附速率受化学过程主导且为单分子层吸附;随着pH的上升,黄钾铁矾去质子化能力增强,对Mo(Ⅵ)的吸附量减小;吸附剂投加量在0.8 g/L时达到吸附饱和,继续增加黄钾铁矾投加量并不能增加Mo(Ⅵ)的去除率;共存阴离子的加入会与Mo(Ⅵ)竞争矿物表面的吸附位点,对吸附起抑制作用;黄钾铁矾对Mo(Ⅵ)的吸附过程中—OH起了关键作用,吸附机制主要为静电吸附和外圈络合吸附的协同作用。

关键词: 黄钾铁矾, 钼酸盐, 吸附, 吸附机理, 重金属废水

Abstract:

Molybdenum is widely distributed in natural mines,primarily as molybdate〔Mo(Ⅵ)〕. With the rapid depletion of molybdenum resources,the discharge of molybdenum-containing industrial effluents will possibly increase,causing serious environmental problems. Jarosite was synthesized by hydrothermal method and applied to remove Mo(Ⅵ) from simulated wastewater. XRD was used to determine the mineral material’s physicochemical properties. Moreover,the effects of adsorption time,initial concentration of Mo(Ⅵ),initial pH,adsorbent dosage,and different coexisting ions on the adsorption behavior were also investigated based on batch experiments. Combined with the change characteristics of functional groups of FT-IR before and after Mo(Ⅵ)adsorption by jarosite,the kinetic characteristics and adsorption mechanism of jarosite on Mo(Ⅵ) were investigated. The results showed that the adsorption process of jarosite on Mo(Ⅵ) met the pseudo-second-order kinetics and the Langmuir model. The adsorption rate was dominated by a chemical process and was a monolayer adsorption. With the increase of pH,the deprotonation ability of jarosite increased,and the adsorption capacity of Mo(Ⅵ) decreased. The adsorption saturation was reached at 0.8 g/L,and the increase of the adsorption effect was limited when the adsorbent dosage continued. The addition of coexisting ions competed with Mo(Ⅵ) for adsorption sites on mineral surfaces and inhibited adsorption. The hydroxyl groups played a key role in the adsorption of Mo(Ⅵ) by jarosite,and the adsorption of Mo(Ⅵ) by jarosite was mainly a synergistic mechanism of electrostatic adsorption and outer ring complexation adsorption.

Key words: jarosite, molybdate, adsorption, adsorption mechanism, heavy metal wasterwater

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