摘要
该实验研究了针铁矿(α-Fe OOH)对废水中Cr(Ⅵ)吸附的影响因素、吸附等温线和吸附动力学。探讨在不同初始浓度、p H、吸附剂的量、离子强度条件下针铁矿对Cr(Ⅵ)的吸附特性。结果表明,针铁矿的吸附平衡时间为30 min;p H为3时,针铁矿对Cr(Ⅵ)的吸附效率最高;Cr(Ⅵ)浓度为15 mg/L时,最佳针铁矿投加量为2 g/L;Cr(Ⅵ)的吸附量随离子强度的升高而降低;温度升高,Cr(Ⅵ)的吸附量随之升高。分别用Langmuir、Freundlich和Temkin等温模型对不同条件下针铁矿吸附Cr(Ⅵ)的实验结果进行模拟,结果表明用Freundlich方程的拟合效果最佳,在35℃时相关性达到了0.995 2。针铁矿吸附Cr(Ⅵ)的吸附动力学满足准二级动力学方程,吸附表观活化能Ea=31.306 k J/mol。实验结果表明,针铁矿在废水除铬(Ⅵ)领域有实际应用的潜力。
Influencing factors,adsorption isotherm and adsorption kinetics of the absorption of chromium on goethite( α-FeOOH) were studied using simulated wastewater.The effects of initial Cr( Ⅵ) concentration, p H, the amount of absorbent,ionic strength on removal of Cr( Ⅵ) by goethite were investigated. Experimental results indicate that adsorption equilibrium of goethite was achieved within 30 min and at p H=3, favors goethite adsorption of Cr( Ⅵ) efficiency is the highest. The concentration of Cr(Ⅵ) at 15mg/L the best goethite dosing quantity was 2 g/L. Adsorption of Cr( Ⅵ) reduced with the increase of ionic strength. Adsorption of Cr(Ⅵ) increase with temperature. Adsorption of Cr(Ⅵ) on goethite at 35 ℃ could be described more exactly by Freundlich equation(R2=0.995 2) than by Langmuir equation and Temkin equation. The adsorption process followed the pseudo-second-order equation. The activation energy(Ea) for the absorption reaction was 31.306 k J/mol. Results of the study suggested that goethite has the potential ability for chromium removal from wastewater.
出处
《环境科学与技术》
CAS
CSCD
北大核心
2015年第S2期72-77,119,共7页
Environmental Science & Technology
基金
北京市产学研项目(51900265005)
国家水污染控制与治理科技重大专项(2009ZX07419-002
2009ZX07207-001
2015ZX07406005)
中央高校基本科研业务费专项(2652013101
2652013086
2652015118
26520150055
2652015006)
重点防控重金属汞
铬
铅
镉
砷便携/车载/在线监测仪器开发与应用示范项目(2012YQ060115)
关键词
针铁矿
铬
吸附等温线
吸附动力学
goethite
chromium
adsorption isotherm
adsorption kinetics
