Arsenic In Ground Research Articles

Unveiling the impact and selectivity of BiVO4/rGO-SiO2 adsorbents for arsenic in ground water: An effective approach for the public safety

The presence of arsenic in ground drinking water has become significant threat to the human health. Herein, BiVO4/rGO-SiO2 adsorbents have been synthesized and utilized first time for the arsenic contents (As (III) & As (V)) removal. Morphology and optical properties of adsorbents have been demonstrated via XRD, FTIR, SEM, EDX, XPS and UV–Vis/DRS. For the large scale implementation, water samples were collected from the different areas of district Bahawalpur, Pakistan. During the removal process, As (III) was oxidized to As (V) and then subsequently adsorbed on BiVO4 assisted rGO-SiO2. Thermodynamic and kinetic studies exhibited a higher fitting Langmuir isotherm (R2 = 0.99) and pseudo-second order (R2 = 0.99) respectively. It has been predicted that adsorption of arsenic is an endothermic process that has ΔH° = 49.18 KJ/mol and negative ΔG° = –1.86801 kJ/mol value. It has been estimated that 10 g of adsorbent is sufficient to remove 99.9 % of arsenic contents. On the basis of results, it has been justified that this work holds promise to replace the conventional adsorbents to get arsenic free water.

Zinc, copper, nickel, and arsenic monitoring in natural streams using in-situ iron–manganese oxide coated stream pebbles

Elements such as zinc, copper, nickel, and arsenic pose a concern for drinking water quality and ecosystem health and tracking these often nonpoint source contaminants in groundwater presents a significant challenge due to the heterogeneous spatial distribution of sources. Developing an approach to help locate the sources of zinc, copper, nickel, and arsenic in ground and surface water sources could potentially provide a rapid, repeatable, and inexpensive technique for environmental assessment. Iron–manganese oxide coated streambed pebbles have a surface affinity for metals and could serve as in-situ monitors. The analysis of pebble coatings and surface water sampled from Pennypack Creek and its tributaries, in southeastern Pennsylvania, USA, tests the ability of pebble coatings to reflect in-stream concentrations of zinc, copper, nickel, and arsenic and track the source of higher concentrations upstream and in tributary branches. Quartz pebbles, 5–7cm in diameter, with brown-red coatings were sampled along the main stem and tributaries of the Pennypack Creek followed by leaching coatings with 4M nitric acid with 0.03M hydrochloric acid for 24h. Quartz pebbles were selected to minimize elemental contamination from metal bearing minerals in the sample. All metals in the leachate are significantly correlated (p<0.15) with iron on the coatings. Zinc, copper, and nickel show elevated concentrations on the pebble coatings near the middle of the watershed compared to concentrations on coatings at other sampling sites. To predict the arsenic source in the main stem, two segments of the Pennypack Creek were chosen for calculations of relative discharge and concentration. Arsenic concentrations (normalized to surface area) on pebbles in the main stems are 5.62ng/cm2 and 12.7ng/cm2 and the predicted values are 13.3ng/cm2 and 28.6ng/cm2 which satisfy mixing within the tributaries. Results suggest that iron–manganese coated stream pebbles are useful indicators of zinc, copper, nickel, and arsenic location within a watershed, but that the source of arsenic differs from that of the other metals of interest. Zinc, copper, and nickel data suggest a geochemical signal from nearby railroads or industrial point source contamination and arsenic data suggests a geogenic source or industrial point source contamination that is traced upstream from a main stem to tributaries using pebble coating concentrations and relative discharge.

Risk Assessment of Ingestion of Arsenic-Contaminated Water among Adults in Bandlaguda, India

Background. The Indian Government describes the Patancheru Industrial Development Area (IDA) near Hyderabad as a heavily polluted site. Previous studies show levels of arsenic in ground and surface...

An Extension of Pnictide Oxide Chemistry – Salt Flux Synthesis and Structure of La5Cu4As4O4Cl2

La5Cu4As4O4Cl2 was prepared from a cold-pressed pellet of lanthanum filings, ground arsenic, Cu2O and LaOCl in the ideal 3 : 4 : 2 : 2 ratio. The pellet was annealed in an evacuated silica tube at 1473 K for two days and then cooled down to room temperature. LaOCl was always observed as a by-product. La5Cu4As4O4Cl2 crystallizes with a new structure type: I4/mmm, a = 413.46(7), c = 4144(1) pm, wR2 = 0.0763, 328 F2 values, 26 parameters. The new quaternary arsenide oxide La3Cu4As4O2 with La3Cu4P4O2-type structure (I4/mmm) was obtained in polycrystalline form: a = 413.0(1), c = 2748.6(1) pm. The structure of La5Cu4As4O4Cl2 is an intergrowth of structural slabs of LaOCl (PbFCl type), ZrCuSiAs- and La3Cu4P4O2-related slabs. The copper atoms have tetrahedral arsenic coordination, and all oxygen atoms fill lanthanum tetrahedra. In the LaOCl slab we observe a van der Waals gap built up by the chloride anions. Half of the arsenic atoms within the La3Cu4P4O2-related slab form As2 4− dumb-bells at an As-As distance of 249 pm. Electronic band structure calculations reveal La5Cu4As4O4Cl2 as a strongly anisotropic hybride material, composed of covalently bonded metallic CuAs4/4 layers, sandwiched between ionic insulating oxide and chloride blocks