Mechanism of fluoride removal by AlCl3 and Al-13: The role of aluminum speciation

CORC > 生态环境研究中心 > 中国科学院生态环境研究中心 > 环境水质学国家重点实验室

	Mechanism of fluoride removal by AlCl3 and Al-13: The role of aluminum speciation
	Wang, Xi; Xu, Hui; Wang, Dongsheng
刊名	JOURNAL OF HAZARDOUS MATERIALS
	2020-11-05
卷号	398 页码:1-8
关键词	Coagulation Al-13 Defluorination ESI-TOF-MS Al species
ISSN号	0304-3894
英文摘要	Coagulation is an important defluorination process. However, because of the poor sedimentation properties, conventional coagulants often result in limited defluorination performance and excessive residual aluminum. In this study, AlCl3 and the highly-positively-charged molecule [AlO4Al12(OH)(24)(H2O)(12)](7+) (Al-13) was utilized to treat fluoride-containing water. By comparison, the role of aluminum speciation in fluoride removal was elucidated. Under initial pH of 6.0, 7.0 and 8.0, the highest defluorination efficiencies of high-fluoride water ([F-](0) = 8.0 mg/ L) were 78.2%, 71.6% and 83.2% at Al-13 dosage of 20 mg/L, 40 mg/L and 50 mg/L. Combined with detailed investigations of the chemical compositions of flocs, along with electrospray ionization time-of-flight mass spectrometry (ESI-TOF-MS) analysis of residual aluminum, the defluorination mechanisms of both coagulants were discussed. In acidic conditions, both coagulants hydrolyzed and formed various Al clusters, among which transient Al (Alts) was the intermediate of the other clusters. The coprecipitation of high-polymerized Al and F- contributed most of the defluorination rate. While under neutral and alkaline conditions, hydrogen bonding and ion exchange together with coprecipitation were the main roles for Al-13. The effects of AlCl3 were merely physical actions, and were affected by the decreased pH. This work provides new insights into the coagulation and defluorination process.
内容类型	期刊论文
源URL	[http://ir.rcees.ac.cn/handle/311016/44959]
专题	生态环境研究中心_环境水质学国家重点实验室
推荐引用方式 GB/T 7714	Wang, Xi,Xu, Hui,Wang, Dongsheng. Mechanism of fluoride removal by AlCl3 and Al-13: The role of aluminum speciation[J]. JOURNAL OF HAZARDOUS MATERIALS,2020,398:1-8.
APA	Wang, Xi,Xu, Hui,&Wang, Dongsheng.(2020).Mechanism of fluoride removal by AlCl3 and Al-13: The role of aluminum speciation.JOURNAL OF HAZARDOUS MATERIALS,398,1-8.
MLA	Wang, Xi,et al."Mechanism of fluoride removal by AlCl3 and Al-13: The role of aluminum speciation".JOURNAL OF HAZARDOUS MATERIALS 398(2020):1-8.