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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Journal ArticleDOI
Hydrothermal carbonization of food waste for nutrient recovery and reuse.
Ifeolu Idowu,Liang Li,Joseph R.V. Flora,Perry J. Pellechia,Samuel Darko,Kyoung S. Ro,Nicole D. Berge +6 more
TL;DR: Experiments evaluating the hydrothermal carbonization of food wastes collected from restaurants indicated that up to 0.96% and 2.30% of nitrogen and phosphorus-based fertilizers in the US can be replaced by the nutrients integrated within hydrochar and liquid-phases generated from thecarbonization of currently landfilled food wastes.
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Applications of Nanomaterials in Environmental Science and Engineering: Review
TL;DR: Using nanomaterials to solve environmental issues will become an inexorable trend in the future as mentioned in this paper, which will create conditions to improve environment and control pollution, which will bring breakthrough progress to environmental science and engineering.
Journal ArticleDOI
Accumulation of heavy metals and trace elements in fluvial sediments received effluents from traditional and semiconductor industries.
Liang-Ching Hsu,Ching Yi Huang,Yen Hsun Chuang,Ho-Wen Chen,Ya Ting Chan,Heng Yi Teah,Tsan-Yao Chen,Chiung-Fen Chang,Yu-Ting Liu,Yu-Min Tzou +9 more
TL;DR: In this article, the authors used principal component analysis (PCA) to determine the metal distribution in relation to environmental factors such as pH, EC, and organic matter (OM) contents in the river basin.
Journal ArticleDOI
Kinetics of competitive adsorption/desorption of arsenate and phosphate at the ferrihydrite–water interface
TL;DR: In this paper, the results of experiments aimed at determining individual and competitive adsorption/desorption kinetics of As(V) and inorganic phosphate (Pi) on ferrihydrite at pH 4 and 8.
Journal ArticleDOI
SYNTHESIS OF BIRNESSITE FROM THE OXIDATION OF Mn2+ BY O2 IN ALKALI MEDIUM: EFFECTS OF SYNTHESIS CONDITIONS
TL;DR: In this article, an O2 oxidation and freeze-dry procedure has been used to synthesize birnessite through the oxidation of Mn2+ in alkali media, where the effects of O2 flow rate, the fluxion velocity of reaction suspension, the reaction temperature, pretreatment the reaction solutions with N2, and the hydration conditions on the purity of Birnessite, the crystallinity, the ion-exchange properties, and phase transformation of intermediate phases were examined.
References
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Journal ArticleDOI
Arsenite and Arsenate Adsorption on Ferrihydrite: Kinetics, Equilibrium, and Adsorption Envelopes
TL;DR: In this paper, the authors compared the adsorption behavior of arsenite and arsenate on ferrihydrite, under carefully controlled conditions, with regard to adaption kinetics and the influence of pH.
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Surface chemistry of ferrihydrite: Part 1. EXAFS studies of the geometry of coprecipitated and adsorbed arsenate
TL;DR: In this article, the As and Fe K-edges were collected from samples of two-line ferrihydrite with adsorbed (ADS) and coprecipitated (CPT) arsenate prepared over a range of conditions and arsenate surface coverages.
Journal ArticleDOI
Arsenic contamination of groundwater and drinking water in Vietnam: a human health threat.
Michael Berg,Hong Con Tran,Thi Chuyen Nguyen,Hung Viet Pham,Roland Schertenleib,Walter Giger +5 more
TL;DR: The high arsenic concentrations found in the tubewells indicate that several million people consuming untreated groundwater might be at a considerable risk of chronic arsenic poisoning.
Journal ArticleDOI
Arsenate and Chromate Retention Mechanisms on Goethite. 1. Surface Structure
TL;DR: In this paper, the authors used Extended X-ray absorption fine structure (EXAFS) spectroscopy to deduce the local coordination environment of two environmental contaminants, arsenate and chromate, on the mineral goethite (α-FeOOH).