摘要
为解决含氟废水中氟离子浓度超标的问题,采用均匀沉淀法制备多孔球状活性氧化镁(PSAM),考察了影响PSAM除氟性能的制备因素,得到其最佳制备条件。通过静态吸附实验和除氟前后PSAM的SEM、BET、EDS、XRD等表征分析,探讨了PSAM的除氟机理和再生效果,分析了PSAM对实际含氟废水的处理效果。结果表明:在n〔CO(NH_(2))_(2)〕∶n(MgCl_(2)·6H_(2)O)=4.5∶1,V(PEG400)∶V(溶剂)=3∶20,110℃反应2 h,450℃煅烧2 h的条件下制备的PSAM除氟性能最佳,在初始氟离子质量浓度为9.9 mg/L时,其对氟离子的吸附量达到18.72 mg/g,除氟率达到86.14%;PSAM的pH_(pzc)=11.82,当pH在2~7之间时PSAM对于氟具有较好的吸附去除性能,吸附过程符合Freundlich吸附等温式和准二级动力学模型,为多层非均匀化学吸附;氟离子主要通过取代PSAM表面的活性位点并与PSAM形成化学键而被去除;PSAM对实际含氟废水的除氟率较传统氧化镁除氟率提高了83.19%,达到了95.83%;经过5次再生循环后,PSAM对氟离子的吸附容量由13.31 mg/g降低到8.35 mg/g。
In order to solve the problem of excessive fluorine ion in fluorine-containing wastewater,porous spherical activated MgO(PSAM)defluorination agent was prepared by using homogeneous precipitation.The preparation fac⁃tors effecting the fluorine removal performance of PSAM were investigated and the optimum preparation conditions were obtained.Through the static adsorption experiment and characterization analysis by SEM、EDS、BET、XRD be⁃fore and after defluorination,the fluorine removal mechanism and regeneration effect of PSAM was discussed,and the treatment effect of PSAM on actual fluorine-containing wastewater was analyzed.The experimental results showed that,the PSAM had the best defluorination performance when prepared in the conditions of n〔CO(NH_(2))_(2)〕∶n(MgCl_(2)·6H_(2)O)=4.5∶1,V(PEG400)∶V(溶剂)=3∶20,reaction at 110℃for 2 h,and calcination at 450℃for 2 h.When the initial fluorine ion mass concentration was 9.9 mg/L,the adsorption capacity was 18.72 mg/g,the defluori⁃nation rate could reach 86.14%.The pHpzc of PSAM was 11.82,that meant it had high fluorine removal performance with pH range from 2 to 7.The adsorption was well described by Freundlich equation and the pseudo-second order kinetic model.The defluorination process of PSAM was multi-layer heterogeneous chemisorption,and the fluorine ions were removed by replacing active points on the surface of PSAM by ion exchange method to form chemical bonds.PSAM had a better treatment effect on actual fluorine-containing wastewater,and the fluorine removal rate was increased by 83.19%and reached 95.83%compared with that of traditional magnesium oxide.After 5 cycles of regeneration,the adsorption capacity decreased from 13.31 mg/g to 8.35 mg/g.
作者
康宁
由昆
徐丽
刘振鹏
黄殿男
高振东
刘琦
曹凯
KANG Ning;YOU Kun;XU Li;LIU Zhenpeng;HUANG Diannan;GAO Zhendong;LIU Qi;CAO Kai(School of Municipal and Environmental Engineering,Shenyang Jianzhu University,Shenyang 110168,China)
出处
《工业水处理》
CAS
CSCD
北大核心
2022年第11期65-75,共11页
Industrial Water Treatment
基金
国家水体污染控制与治理科技重大专项(2018ZX07601001-3)。
关键词
含氟废水
多孔球状活性氧化镁
吸附
吸附等温线
吸附动力学
再生
fluorine-containing wastewater
porous spherical activated MgO
adsorption
adsorption isotherm
ad⁃sorption kinetics
regeneration
