Journal ArticleDOI
Competitive Sorption of Arsenate and Phosphate on Different Clay Minerals and Soils
Antonio Violante,Massimo Pigna +1 more
TLDR
In this article, the competitive sorption of PO 4 and AsO 4 on selected phyllosilicates, metal oxides, synthetic organo-mineral complexes, and soil samples as affected by pH (4.0-8.0), ligands concentration, surface coverage of the oxyanions on the samples and the residence time.Abstract:
Sorption and desorption of AsO 4 on or from different soil components may have a dominant role in regulating As mobility in soils. The objectives of this work were to provide information on the factors that influence the competitive sorption of AsO 4 and PO 4 in soil. We studied the competitive sorption of PO 4 and AsO 4 on selected phyllosilicates, metal oxides, synthetic organo-mineral complexes, and soil samples as affected by pH (4.0-8.0), ligands concentration, surface coverage of the oxyanions on the samples and the residence time. We found that Mn, Fe, and Ti oxides and phyllosilicates particularly rich in Fe (nontronite, ferruginous smectites) were more effective in sorbing AsO 4 than PO 4 . In fact, by adding AsO 4 and PO 4 as a mixture (AsO 4 /PO 4 molar ratio of 1) more AsO 4 , than PO 4 was usually sorbed on birnessite, pyrolusite, goethite, nontronite, and ferruginous smectite, but more PO 4 than AsO 4 was sorbed on noncrystalline Al precipitation products, gibbsite, boehmite, allophane, and kaolinite. For example, at pH 5.0 the sorbed AsO 4 /sorbed PO 4 molar ratio (rf) was 1.81 for bimessite, 1.05 for nontronite, but was only 0.45 for kaolinite and 0.14 for allophane. For montmorillonite, illite, and vermiculite the rf values were slightly <1. For soil samples, particularly rich in kaolinite, halloysite, allophane, and containing relatively large amounts of organic C, the rf values were usually much <1. For all the samples, the rf values increased by decreasing the pH and with the residence time of the oxyanions. The sorption of AsO 4 (or PO 4 ) on goethite and gibbsite decreased by increasing the initial PO 4 /AsO 4 (or ASO 4 / PO 4 molar ratio) up to 2.0. However, PO 4 inhibited AsO 4 sorption more on gibbsite than on goethite, whereas AsO 4 prevented PO 4 sorption more on goethite than on gibbsite. The data reported in this paper suggest that the mobility, the bioavailability, and the toxicity of As in soil environments may be greatly affected by the nature of soil components, pH, presence of anions (PO 4 ), and residence time.read more
Citations
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Book
Heavy metals in soils : trace metals and metalloids in soils and their bioavailability
TL;DR: In this article, the authors defined the sources of heavy metals and metalloids in Soils and derived methods for the determination of Heavy Metals and Metalloids in soil.
Journal ArticleDOI
Mobility and bioavailability of heavy metals and metalloids in soil environments
TL;DR: In this paper, the impact of physical, chemical, and biological interfacial interactions on bioavailability and mobility of metals and metalloids in soil is highlighted, focusing on the sorption/desorption processes of metals on/from soil components and soils.
Book ChapterDOI
The geochemistry of acid mine drainage
David W. Blowes,Carol J. Ptacek,John L. Jambor,Christopher G. Weisener,Dogan Paktunc,W.D. Gould,D.B. Johnson +6 more
TL;DR: In this article, the authors developed and applied molecular tools to determine the activity and role of microorganisms in sulfide-mineral-bearing systems and developed tools for assessing the toxicity of mine-waste effluent.
Journal ArticleDOI
Arsenic and chromium removal by mixed magnetite-maghemite nanoparticles and the effect of phosphate on removal.
TL;DR: Magnetite-maghemite nanoparticles can readily adsorb arsenic and chromium in an acidic pH range, and it is anticipated that an optimum design with magnetite- maghemites nanoparticles may achieve high arsenic uptake in field applications.
Journal ArticleDOI
Effect of magnetite particle size on adsorption and desorption of arsenite and arsenate
Sujin Yean,Lili Cong,Cafer T. Yavuz,J. T. Mayo,William W. Yu,Amy T. Kan,Vicki L. Colvin,Mason B. Tomson +7 more
TL;DR: In this paper, the effect of magnetite particle size on the adsorption and desorption behavior of arsenite and arsenate was evaluated, and a substantial decrease in arsenic sorption to magnetite nanoparticles was observed.
References
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Journal ArticleDOI
Comparison of salt titration and potentiometric titration methods for the determination of Zero Point of Charge (ZPC)
TL;DR: In this paper, the salt titration method was evaluated as a method to determine ZPC in comparison with the potentiometric titration (PT) method for 26 soils with variable charge clays.
Journal ArticleDOI
Competitive Coefficients for the Adsorption of Arsenate, Molybdate, and Phosphate Mixtures by Soils1
Comparison of salt titration and potentiometric titration methods for the determination of zero point of charge (ZPC) [Japan and Thailand]
K. Sakurai,Y. Ohdate,K. Kyuma +2 more
Journal ArticleDOI
Effect of Adsorbed Phosphate on Transport of Arsenate through an Oxisol
TL;DR: In this article, the competitive nature of sorbed phosphate on arsenate mobility was investigated using laboratory soil columns constructed from an aggregated Oxisol; the soil was incubated with four levels of phosphate (0-48.6 mmol P kg -1 ) before being leached with 0.66 mmol KH 2 AsO 4 L -1 in 0.05 M KCl.
Journal ArticleDOI
Analysis of metal cations and inorganic anions in olive oil mill waste waters by atomic absorption spectroscopy and ion chromatography. Detection of metals bound mainly to the organic polymeric fraction.
Michele Arienzo,Renato Capasso +1 more
TL;DR: Metal cations were quantitatively detected by atomic absorption spectrometry in samples of olive oil mill waste waters obtained by a pressure process and revealed to be bound to the omww organic polymeric fraction (opf), composed of polysaccharides, phenol polymers, and proteins.