Adsorption, which is a quick and effective method for phosphate management, can effectively address the crisis of phosphorus mineral resources and control eutrophication. Phosphate management systems typically use iron-containing nanominerals (ICNs) with large surface areas and high activity, as well as modified ICNs (mICNs). This paper comprehensively reviews phosphate management by ICNs and mICNs in different water environments.
View Article and Find Full Text PDFThe electroplating wastewater containing various metal ions was treated by adding sodium dodecyl benzene sulfonate (SDBS) and regulating pH value, and the resulting precipitates were characterized by X-ray diffraction (XRD). The results showed that organic anions intercalated layered double hydroxides (OLDHs) and inorganic anions intercalated layered double hydroxides (ILDHs) were in-situ formed to remove heavy metals during the treatment process. In order to reveal the formation mechanism of the precipitates, SDB intercalated Ni-Fe OLDHs, NO intercalated Ni-Fe ILDHs and Fe-DBS complexes were synthsized by co-precipitation at various pH values for comparison.
View Article and Find Full Text PDFGlacial sediments as an important end member of the global dust system, could indicate changes in global climate, aerosols sources, ocean elements, and productivity. With global warming, ice caps shrinking and glaciers retreat at high latitudes have attracted concern. To understand the response of glacier to environment and climate in modern high latitude ice-marginal environments, this paper investigated glacial sediments in the Ny-Ålesund region of the Arctic and clarified the response of polar environmental to global changes through geochemical characteristics of glacial sediments.
View Article and Find Full Text PDFThe lamella aggregation state of layered double hydroxides (LDHs) may affect their sorption capacity for organic compounds. The dried LDH samples (Ni/Cr LDH-FA-D and Ni/Cr LDH-HO-D) and the undried samples (Ni/Cr LDH-FA-W and Ni/Cr LDH-HO-W) were flexibly prepared by a co-precipitation method in formamide (FA) and water, respectively. The results of X-ray diffraction (XRD) and transmission electron microscope (TEM) showed that the undried LDHs were unassembled, which had no the stacking layers but had a pseudohexagonal nanosheet lamella structure.
View Article and Find Full Text PDFDue to the supply-side reform and environmental protection in China, many small coal mines have been closed since 2015. However, acid mine drainage from these coal mines are continuously discharging into many rural creeks, which requires the systematical investigation on the variations of geochemical and environmental biological aspects in these water systems. In this study, from a classic acid mine drainage (AMD) from a closed coal mine of Hunan, China, various sediments and water samples in different sections were collected and analyzed.
View Article and Find Full Text PDFDue to abundant biomass and eco-friendliness, biochar is exemplified as one of the most promising candidates to mediate the degradation of environmental contaminants. Recently, environmentally persistent free radicals (EPFRs) have been detected in biochars, which can activate SO or HO to generate reactive oxygen species for effective degradation of organic and inorganic contaminants. Comprehending the formation mechanisms of EPFRs in biochars and their interactions with contaminants is indispensable to further develop their environmental applications, e.
View Article and Find Full Text PDFThe study evaluated source apportionment of heavy metals in vegetable samples from the potential sources of fertilizer, water and soil samples collected along the Changjiang River delta in China. The results showed that 25.72% of vegetable samples (Brassica chinensis L.
View Article and Find Full Text PDFIn this study, lignin was selected as the main component of waste biomass to synthesise carbonaceous adsorbents with environmentally persistent free radicals (EPFRs) through hydrothermal carbonisation (HTC) under different conditions. The HTC method with Fe(III) doping was superior for promoting dehydration and decarboxylation of lignin hydrochar than that with HTC Cu(II) doping. The deconstruction of oxygen-containing groups of lignin was reduced while esterification was enhanced by Fe(III).
View Article and Find Full Text PDFMater Sci Eng C Mater Biol Appl
August 2017
In this article, the authors report the adsorption of iodide by Mg/Al LDHs and thermally activated LDH materials in laboratory scale batch experiments. The optimal Mg/Al cation ratio was 3:1while the percentage iodide uptake increased with increasing adsorbent dose up to 1g/20mL of solution. The effect of initial iodide concentration was investigated using the Langmuir and Freundlich adsorption isotherm models, while the pseudo second order kinetic model appeared to provide the best fit for the experimental data.
View Article and Find Full Text PDFConsumption of crops grown in cadmium-contaminated soils is an important Cd exposure route to humans. The present study utilizes statistical analysis and in vitro digestion experiments to uncover the transfer processes of Cd from soils to the human body through rice consumption. Here, a model was created to predict the levels of bioaccessible Cd in rice grains using phytoavailable Cd quantities in the soil.
View Article and Find Full Text PDFSpectrochim Acta A Mol Biomol Spectrosc
June 2017
Portable visible and near-infrared (vis/NIR) spectroscopy was used to characterize and differentiate the five phyllosilicate minerals and relate the bands to the mineral structure. The feature band at 2160-2170nm (4600-4630cm) has been assigned to the high presence of Al-OH and is described as typical of dioctahedral phyllosilicate with OH groups coordinated around Al, and the feature occurred near 2322nm is considered to be due to a combination of the OH stretch with the MgOH deformation mode, which is a typical of trioctahedral phyllosilicates. The presence of the bands 1400 and 1900nm in vis/NIR spectrum indicated that some water is present in this sample.
View Article and Find Full Text PDFApplication of inorganic-organic clays (IOCs) for the remediation of hexavalent chromium (Cr (VI)) and the effect of bisphenol-A (BPA) were investigated. IOCs were better adsorbents for the removal of Cr (VI) than organoclay. Solution pH significantly affected the surface charge of IOCs and speciation of Cr in the solution; hence, the adsorption of Cr onto IOCs.
View Article and Find Full Text PDFA novel medium containing iron oxide-based porous ceramsite (IPC) and commercial ceramsite (CC) was used in two laboratory-scale upflow biological aerated filters (BAFs) to treat city wastewater to compare their efficacy in wastewater treatment. The IPC BAF and CC BAF were operated in water at 20-26°C, an air/water (A/W) ratio of: 3:1 and hydraulic retention times (HRTs) of 7, 3.5, 1.
View Article and Find Full Text PDFHilarionite (Fe2 (SO4)(AsO4)(OH)·6H2O) is a new Fe sulphoarsenates mineral, which recently is found in the famous Lavrion ore district, Atliki Prefecture, Greece. The spectroscopic study of hilarionite enriches the data of arsenic mineralogy in supergene environment of a mine area. The infrared and Raman means are used to characterize the molecular structure of this mineral.
View Article and Find Full Text PDFJ Colloid Interface Sci
September 2016
Several studies have previously demonstrated that layered double hydroxides (LDHs) show considerable potential for the adsorption of radioiodine from aqueous solution; however, few studies have demonstrated that these materials are able to store radioactive (131)I for an acceptable period. The leaching of iodide (I(-)) and iodate (IO3(-)) form Mg/Al LDHs has been carried out. Contact time appeared to be a more significant variable for the leaching of iodate (IO3(-)) compared to that of iodide (I(-)).
View Article and Find Full Text PDFBisphenol-A (BPA) adsorption onto inorganic-organic clays (IOCs) was investigated. For this purpose, IOCs synthesised using octadecyltrimethylammonium bromide (ODTMA, organic modifier) and hydroxy aluminium (Al13, inorganic modifier) were used. Three intercalation methods were employed with varying ODTMA concentration in the synthesis of IOCs.
View Article and Find Full Text PDFSpectrochim Acta A Mol Biomol Spectrosc
February 2016
A novel method has been presented to characterize electron transfer in layered double hydroxides (LDHs) utilizing an investigation combing FTIR and infrared emission spectroscopy. At room temperature, electron could transfer to interlayer Fe(3+) through monodentate ligand cyanide, and resulted in a reduction of 40% Fe(3+) to Fe(2+). When the environmental temperature increased from 25 to 300°C, reduction of Fe(3+) and Ni(2+) increased to 94% and 42%.
View Article and Find Full Text PDFThe compound-specific mechanisms for the sorption of organic contaminants onto cetyltrimethylammonium-saturated bentonite (i.e., CTMA-Bentonite) in water were evaluated by (1)H NMR study and Linear Solvation Energy Relationship (LSER) approach.
View Article and Find Full Text PDFSpectrochim Acta A Mol Biomol Spectrosc
January 2016
A better understanding of mineral transformations in sedimentary rocks and the controls on thermal maturity have become essential in the petroleum exploration industry in recent years. The Fushan Depression is an important hydrocarbon-bearing depression in South China Sea, which can be subdivided into three structural zones: the western, central and eastern zones. In this study, a series of mudstone samples selected from 13 drilling cores with depths ranging from 2100 to 3800 m were studied using infrared reflectance spectroscopy and X-Ray Powder Diffraction (XRD) methods.
View Article and Find Full Text PDFInorganic-organic clays (IOCs), clays intercalated with both organic cations such as cationic surfactants and inorganic cations such as metal hydroxy polycations have the properties of both organic and pillared clays, and thereby the ability to remove both inorganic and organic contaminants from water simultaneously. In this study, IOCs were synthesised using three different methods with different surfactant concentrations. Octadecyltrimethylammonium bromide (ODTMA) and hydroxy aluminium ([Al13O4(OH)24(H2O)12](7+) or Al13) are used as the organic and inorganic modifiers (intercalation agents).
View Article and Find Full Text PDFSpectrochim Acta A Mol Biomol Spectrosc
December 2015
Hydrocalumite (CaAl-LDH-Cl) interacted with a natural anionic surfactant, sodium hexadecyl sulfate (SHS), was performed using an intercalation method. To understand the intercalation behavior and characterize the resulting products, powder X-ray diffraction (XRD), scan electron microscopy (SEM) and mid-infrared (MIR) spectroscopy combined with near-infrared (NIR) spectroscopy technique were used. The XRD analysis indicated that SHS was intercalated into CaAl-LDH-Cl successfully, resulting in an expansion of the interlayer (from 0.
View Article and Find Full Text PDFSpectrochim Acta A Mol Biomol Spectrosc
December 2015
We have studied the mineral rostite, a sulphate mineral of aluminium of formula AlSO4(OH,F)·5(H2O). The mineral is formed in mine dumps and wastes. Chemical analysis proves the presence of Al, F and S.
View Article and Find Full Text PDFSpectrochim Acta A Mol Biomol Spectrosc
December 2015
The mineral liskeardite, an arsenate mineral with major cations of iron and aluminium, has been studied by a combination of scanning electron microscopy with energy dispersive spectroscopy and Raman spectroscopy. The mineral shows a fibrous nature. Semi-quantitative chemical analysis shows an Al and Fe arsenate phase with minor amounts of K, Cu, S and Si.
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