terms and conditions of current drinking water quality standards, including reducing the maximum arsenic concentration from 50 μgl-1 to 10 μgl-1 and predicted stricter standards in future, reveals the necessity for development of new technologies. this study aimed to prepare and evaluate a new nanocomposite membrane using graphene oxide (go) thin layer to remove arsenic (v) from water. to fabri...

Arsenate does this because the enzyme accepts it as orthophosphate, but the first product breaks down because of the instability of esters and anhydrides of arsenate (cf. Braunstein, 1931). This use of arsenate is limited because most of the biochemical reactions that liberate orthophosphate, in contrast with those that liberate pyrophosphate, are not freely reversible. Arsenical analogues of p...

The title compound, sodium calcium trimagnesium tris-(arsenate), an alluaudite-like arsenate, was prepared by solid-state reaction at high temperature. The structure is built up from edge-sharing MgO(6) octa-hedra in chains associated with the AsO(4) arsenate groups. The three-dimensional network leads to two different tunnels occupied statistically by Na(+) and Ca(2+). One As and one Mg atom l...

The competitive adsorption of arsenate and arsenite with silicic acid at the ferrihydrite-water interface was investigated over a wide pH range using batch sorption experiments, attenuated total reflectance Fourier transform infrared (ATR-FTIR) spectroscopy, extended X-ray absorption fine structure (EXAFS) spectroscopy, and density functional theory (DFT) modeling. Batch sorption results indica...

The presence of potentially toxic elements and compounds in foodstuffs is of intense public interest, and so food producers as well as regulators require rapid, reliable screening methods to accurately determine the levels of such contaminants in food and drink. In the case of arsenic (As), concentration levels in foods may be increased through the historical use of As-containing agrochemicals ...

The phosphotransacetylase from Clostridium acidiurici has two properties not observed for this enzyme in other bacteria: (i) it requires a divalent metal for activity, and (ii) it is not subject to uncoupling by arsenate. The enzyme has been obtained in highly purified form, with a specific activity 500-fold higher than crude extracts. Ferrous or manganous ions are required for maximal activity...

Niu-Huang-Jie-Du Pian (NHJD) is a widely used traditional Chinese medicine containing realgar (As4S4). Realgar has been included in many traditional medicines, but is often taken as arsenite for risk assessment. To evaluate true risk of realgar and realgar-containing NHJD, their toxicity was compared with common arsenicals. In cultured cells, the LC50 for NHJD (1200 μM) and realgar (2000 μM) wa...

Rice (Oryza sativa L.) is the most important crop all over the world. It is considered the main 19 food of 50% of the world population especially in Egypt. However, rice not only accumulates some of 20 heavy metals such as cadmium but also accumulate arsenate (As). Arsenic contamination in water and 21 food resulted in many implications for millions of people leading cancer. For that reason, th...

Some pesticide chemicals are based on inorganic elements such as sulfur, copper (i.e. copper sulfate ‘Bordeaux mixture’, copper hydroxide, and copper oxychloride), and arsenic salts (i.e. lead arsenate, calcium arsenate, sodium arsenite), or they contain an inorganic element in their chemical structure such as the organometallic pesticides based on manganese dithiocarbamate (maneb), manganese a...

Arsenic toxicity has been studied for a long time due to its effects in humans. Although epidemiological studies have demonstrated multiple effects in human physiology, there are many open questions about the cellular targets and the mechanisms of response to arsenic. Using the fission yeast Schizosaccharomyces pombe as model system, we have been able to demonstrate a strong activation of the M...