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Adsorption of fluoride, chloride, bromide, and bromate ions on a novel ion exchanger

“…Sorption capacity then decreased slowly and reached a small, second peak at pH 9. Sorption of bromate ions was approximately equal through the whole pH interval investigated (3)(4)(5)(6)(7)(8)(9)(10), with some small maxima at pH 3 and 9-10. This anion has another mechanism of sorption (confirmed by isotherms, see Fig.…”

“…Wastewater from phosphate fertilizer plants may contain up to 2% of fluoride [2]. Increased levels of fluoride can also be present in effluents from the fluorine industry, from glass etching [2], and in groundwater around aluminum smelters [3,4].…”

Interactions between variable-charge soils and acidic solutions containing fluoride: an investigation using repetitive extractions

“…As a matter of fact, besides H + -promoted breakdown of soil minerals, it has been found that high F-pollution could induce breakdown of Al oxides/hydroxides, which should contribute greatly to the enhancement in Al dissolution [9,18,[30][31][32]. F sorption is a precursor to Al dissolution.…”

“…F is also present in phosphogypsum, which has been suggested as an ameliorant for acid soils. In addition, soils in the vicinity of aluminum smelters are often highly contaminated with F originating from the smelter emissions [8][9][10]. It has been found that F contents in some polluted variablecharge soils in Chinese coastal areas could be as high as 52.6 µmol/g [11].…”

“…There has long been concern with Al-F complexation in soil and water systems because dissolved F, even at very low concentrations (10 −6 mol/L), has a dramatic influence on Al speciation and adsorption between solid phases and solution. Several authors have observed in batch experiments that the formation of Al-F complexes could result in Al desorption and enhancement in Al solubility [9,10,12]. Strong complexation of Al-F is also environmentally important because the complexation might mitigate largely the toxicity of aqueous Al.…”