《Journal of Colloid and Interface Science》杂志刊登“可变电荷土壤中氟的吸附和铝的释放”

 
作 者：Laura F Harrington, Ellen M Cooper, Dharni Vasudevan
刊 物：《Journal of Colloid and Interface Science》，2003年，267卷第2期，302-313页
关键词：氧化铁；金属氧化物；吸附；溶解；降水量；络合；老成土
摘 要：本文以两种富含铁氧化物的土壤为研究对象，探讨土壤深度、组成、物理-化学特性以及氟-土壤表层的相互作用对土壤吸附氟和释放铝的影响。试验过程中，氟化物吸附平衡后，检测铝的浓度，结果表明溶解的铝和释放的固相铝浓度之间达到净平衡，并且氟化物促进含铝土壤矿物中铝的溶出。在氟化物存在下，即使类似土壤深度和剖面的土壤，释放的铝含量截然不同，分析主要原因可能是由于土壤吸附氟的机理、土壤矿物学、铝和铁的反应机理、土壤水化学性质等各不相同。氟化物吸附与呈现高表面积非晶态和水晶氧化物阶段的铝和铁有相关性强。土壤吸附氟的主要机理是氟化物代替铝和铁化合物的羟基，并与之络合在一起。在氟化物浓度较高时，土壤对氟的截留主要包括AlF络合物、土壤孔隙溶液、沉淀等机理，亦有可能粘附在土壤表面。

Fluoride sorption and associated aluminum release in variable charge soils

Authors: Laura F Harrington, Ellen M Cooper, Dharni Vasudevan
Journal: Journal of Colloid and Interface Science, Volume 267, Number 2 (2003), 302-313
Key words: Iron oxide; Metal oxide; Adsorption; Dissolution; Precipitation; Complexation; Ultisols
Abstract: Fluoride sorption and related aluminum (Al) release are evaluated in two iron-oxide-rich soils as a function of soil depth, composition, and physical–chemical properties and potential mechanisms of fluoride–surface interaction are suggested. Measured Al concentrations at equilibrium fluoride sorption, reflective of the net balance between Al dissolution and sequestration of the released Al by the solid phase, suggest net fluoride-assisted dissolution of Al-bearing amorphous and crystalline soil minerals. Strikingly, soils of similar depth and horizonation from the same soil order but of distinct soil series exhibited markedly different susceptibility to Al loss in the presence of fluoride, possibly a combined result of differences in the mechanism of fluoride sorption, soil mineralogy, reactivity of the surficial Al and Fe, and soil solution chemistry. Fluoride sorption is strongly correlated with soil Al and Fe present as high-surface-area amorphous and crystalline oxide phases. Fluoride complexation to surficial Al and Fe ions via ligand exchange with surficial OH groups and water molecules appears to be the dominant sorption mechanism. At high dissolved fluoride concentrations (>7 mM), other mechanisms of fluoride retention including adsorption of AlF solution complexes, entrapment in the interparticle pore fluid, and precipitation into solution and/or onto the soil surface are also likely.

原文链接：http://www.sciencedirect.com/science/article/pii/S002197970300609X
翻译：孙瑞刚；审核：陈康宁