摘要
以烟气脱硫(FGD)石膏作为除氟剂,通过沉淀法去除高浓度含氟废水中的氟离子,并对FGD石膏除氟机理进行了探讨。单因素条件实验结果表明,在FGD石膏用量10.744 g/L、pH=7、反应时间30 min、反应温度25℃的最佳实验条件下,含氟废水的F^-浓度可从1 500 mg/L降至89.13 mg/L,除氟率可达94.06%。溶液化学分析结果表明,当溶液pH=5～11时,溶液中Ca^(2+)与F^-的浓度较高,而CaF_2的溶解度较小,FGD石膏在溶液中释放出的Ca^(2+)与F^-结合生成难溶的CaF_2沉淀,从而将F^-从溶液中去除。XRD、SEM-EDS等结果表明,反应生成的难溶CaF_2以壳状形式均匀稳定地包裹在FGD石膏表面,从而实现高浓度含氟废水的净化。
Flue gas desulfurization ( FGD) gypsum was used as a defluoridation agent to remove fluoride ions from wastewater with high content of fluorine by precipitation,and the fluorine removal mechanism was also discussed. The results of single factor experiment showed that the F- concentration of fluorine-containing wastewater was reduced from 1 500 mg /L to 89.13 mg /L under the optimal conditions including the FGD gypsum dosage at 10.744 g /L,pH = 7, reaction time of 30 min and reaction temperature at 25 ℃,with the fluoride removal rate reaching 94.06%. The chemical analysis of the solution showed concentration of Ca2+ and F- was higher and solubility of CaF2 was lower in the solution with pH= 5~11. The Ca2+ released from FGD gypsum in the solution combined with F-,forming an insoluble CaF2 precipitates,consequently resulting in F- removed from the solution. XRD and SEM-EDS results showed that the insoluble CaF2 formed by the reaction uniformly and stably wrapped on the surface of FGD gypsum as a shell,thus achieving the purpose of purification of such high-fluorine-content wastewater.
作者
苟晓琴
韩海生
孙伟
刘润清
亢建华
GOU Xiao-qin;HAN Hai-sheng;SUN Wei;LIU Run-qing;KANG Jian-hua(School of Minerals Processing and Bioengineering,Central South University,Changsha 410083,Hunan,China)
出处
《矿冶工程》
CAS
CSCD
北大核心
2019年第2期97-101,共5页
Mining and Metallurgical Engineering
基金
国家自然科学基金重点项目(51634009)
国家自然科学基金青年项目(51804340)
关键词
废水处理
高浓度含氟废水
烟气脱硫石膏
沉淀法
溶液化学分析
除氟
净化
wastewater treatment
high-fluoride-content wastewater
flue gas desulfurization gypsum
precipitation method
chemical analysis of solution
fluorine removal
purification
