载铁活化天然沸石处理高氟地下水

采用氯化铁改性天然沸石进行地下水除氟效果的研究,考察了地下水中4种阴离子Cl-、HCO3-、SO24-和PO34-对该改性沸石除氟效果的影响,并分析了其除氟机理和表面成分。研究结果表明,对于初始氟浓度不同的水样,随着阴离子浓度的增加,吸附剂对氟的去除率逐渐下降。Cl-对吸附剂除氟效果影响较小,氟去除率降低较慢;随着HCO3-浓度的增大(由100 mg/L到1 000 mg/L),水样pH由8.42缓慢升高到9.52,而氟去除率则由70.36%缓慢下降到56.73%(2mg/L);SO24-及PO34-对改性沸石除氟效果影响较大,氟去除率降低较快,且PO34-的影响大于SO24-。可以得到载铁活化天然沸石对4种阴离子的吸附顺序为:PO34->SO24->HCO3->Cl-。

Fluoride removal from groundwater by FeCl3-activated natural zeolite

Effects of four anions in groundwater: Cl^-, HCO₃^-, SO₄^2- and PO₄^3- on the capacity of defluoridation of FeCl₃-activated natural zeolite were investigated. The mechanism of defluorination and surface composition of adsorbent were analyzed. The results showed that the removal efficiencies of fluoride for different initial fluoride concentrations of water samples were gradually reduced with the increasing concentrations of anions. Effect of Cl^- on the adsorbent was tiny with slower decrease of fluorine removal rate. With the increase of HCO₃^- concentration (from 100 mg / L to 1 000 mg / L), pH of water slowly increased to 9.52 from 8.42, and removal efficiency of flouride tardily declined from 70.36% to 56.73% (2 mg/L). Effects of SO₄^2-and PO₄^3- on the capacity of defluoridation of the modified zeolite were greater, with rapid decrease of fluorine removal rate. And the impact of PO₄^3- was greater than SO₄^2-. The adsorption capacity of FeCl₃-activated natural zeolite on Cl^-, HCO₃^-, SO₄^2- and PO₄^3- was PO₄^3->SO₄^2->HCO₃^->Cl^-.