— In a previous study, the positive effect on gold extraction from arsenopyrite was shown to coincide with the release of arsenic during the two processing stages (Mesa Espitia and Lapidus, 2015). The refractory mineral studied in this research required an alkaline pretreatment with NaOH, prior to the gold leaching with sodium thiosulfate to ...

 — Abstract— This paper presents results of analysis of the patent, scientific, and technical literature concerned with the physicochemical and technological foundations of the preparation of high-purity arsenic-containing compounds from various raw materials. Considerable attention is paid to processing of unconventional raw materials (ite …

 — While the exact mechanism is unclear, aberrant changes in genome and gene expression are suggested as an underlying process. Carcinogenic metals such as arsenic, cadmium, and chromium can disrupt DNA synthesis and repair (Clancy et al., 2012; Koedrith et al., 2013). The toxicity and carcinogenicity of heavy metals are dose dependent.

 — Soaking will be an alternative process to remove arsenic in brown rice. Abstract. One of the main food crops in the world, rice can accumulate high levels of arsenic from flooded paddy soils, which seriously threatens human health. Soaking, a common processing method for brown rice products, especially for brown rice noodles, was …

 — 1. Introduction. Arsenopyrite, the main arsenic-containing mineral, has emerged as the major source of environmental arsenic pollution. However, despite the ubiquity of arsenopyrite and the potential environmental impact and health hazards of arsenic on the environment, limit information is available regarding the stability and …

Arsenic is released into the air by volcanoes, through weathering of arsenic-containing minerals and ores, and by commercial or industrial processes. Arsenic occurs naturally in the earth's crust, and much of its dispersion …

Arsenic is a worldwide environmental pollutant and a human carcinogen. It is well recognized that the toxicity of arsenicals largely depends on the oxidoreduction states (trivalent or pentavalent) and methylation levels (monomethyl, dimethyl, and trimethyl) that are present during the process of metabolism in mammals.

 — The metalloid arsenic is a natural environmental contaminant to which humans are routinely exposed in food, water, air, and soil. Arsenic has a long history of use as a homicidal agent, but in the past 100 years arsenic, has been used as a pesticide, a chemotherapeutic agent and a constituent of consumer products.

 — The toxicity of arsenic spans across the tree of life, affecting microbes, plants, and animals (Jayasumana et al., 2015; Mandal and Suzuki, 2002; Molin et al., 2015; Podol'skaya et al., 2002) Arsenic contamination of soil and water in various parts of the world is an outcome of natural and/or anthropogenic sources such as mining, industrial ...

 — The aim of this study was to propose an intermediate processing stage (ii), between alkaline pretreatment (i) and gold leaching (iii), to remove the greatest amount …

 — Arsenic is used industrially as an alloying agent, as well as in the processing of glass, pigments, textiles, paper, metal adhesives, wood preservatives and ammunition. Arsenic is also used in the hide tanning …

 — The solution used for arsenic precipitation process is a mixture of the solution after copper precipitation and washing solution in the copper precipitation process, and the chemical composition is presented in Table 11. The contents of Zn, As T and As(III) were 19.88, 11.86 and 4.75 g/L, respectively.

 — Arsenic may be present in food from the environment where foods are grown, raised, or processed. ... processing, and manufacturing foods that contain lower levels of environmental contaminants ...

 — Arsenic, a metalloid that exists by nature, reaches the earth either by natural or anthropogenic events and is considered an emerging pollutant. The existence of arsenic in soil systems is a fate to the environment since it is mobile and being transported to other systems because of its bioavailability and speciation process. Arsenic transformation in …

 — Arsenic can also be methylated in the process of biological methylation, facilitated by microorganisms such as fungi, bacteria, algae, and phytoplankton. This methylation process can lead to the formation of organo-As compounds, including monomethylarsonous acid [CH 3 As (OH) 2 ], dimethylarsonous acid [(CH 3 ) 2 As (OH) …

 — Arsenic is a naturally occurring element in the environment. Rock, soil, water, air, plants and animals all contain some level of arsenic. Arsenic combines with inorganic and organic substances to form many different compounds. Inorganic compounds. Arsenic combines with oxygen, chlorine and sulfur to create inorganic arsenic compounds.

 — Arsenic-free acid (96% strength) was produced by the vanadium-catalyzed contact process due to the fact that arsenic-free starting materials had to be used because of poisoning of the catalyst by arsenic. There were many uses for the less-concentrated, and therefore cheaper, acid: two products in particular suffered from the presence of …

arsenic xide into crystalline scorodite (FeAs0 4 • 2HzO) using acidic nitrate solu­ tions at temperatures ranging from 140°C to 160"C. A schematic process flow sheet is proposed. The reasons for processing arsenic xide, especially baghouse dust from met­ allurgical operations, lie in its toxic charac­

Arsenic contaminations, often adversely influencing the living organisms, including plants, animals, and the microbial communities, are of grave apprehension. Many physical, chemical, and biological techniques are now being explored to minimize the adverse affects of arsenic toxicity. Bioremediation of arsenic species using arsenic loving bacteria has …

The purpose of this briefing is to provide a general overview about the occurrences of arsenic, its economic uses, and its environmental and health impacts. ... The mining, mineral processing and metallurgical industries support and strictly follow state and federal regulations to ensure protection of the environment and the health of industry ...

 — With new environmental legislation, demand arose for a simple and low-cost technology for arsenic waste processing into the disposable form. One of the cheapest methods consists of precipitation with lime. It has been proven however, that resulting solids are unstable when exposed to atmospheric carbon dioxide[1]. Another wide-spread and ...

 — With new environmental legislation, demand arose for a simple and low-cost technology for arsenic waste processing into the disposable form. One of the cheapest methods consists of precipitation with lime. It has been proven however, that resulting solids are unstable when exposed to atmospheric carbon dioxide [1].

 — A hydrothermal upgrading process was developed for removal of heavy metals, including arsenic, lead, zinc and copper, and upgrading bio-oil from P. vittata and a heavy metals removal efficiency of >99% and crude bio-oil upgrading efficiency of 83.76% were attained under the determined conditions. The hydrothermal upgrading bio-oil …

This paper presents the effect of pH and redox potential on the potential mobility of arsenic (As) from a contaminated mineral processing waste. The selected waste contained about 0.47 g kg(-1) of As and 66.2 g kg(-1) of iron (Fe). The characteristic of the waste was identified by acid digestion, X- …

 — Arsenic speciation analysis on the collected samples showed that As associated with δ-MnO 2 was present as As(V) and no As(III) was observed in the effluent during the desorption phase (Lafferty et al ... Using a process-based modeling approach, this study evaluated a conceptual model that reflects the widely accepted mechanisms …

Arsenic is commonly found as an impurity in sulfide ores, and is produced commercially for use in pesticides, wood preservatives, metal alloys, and other technologies. It is also listed as critical mineral under Presidential executive order 13817, because it has important uses in our economy, …

 — Table IV shows the level of development of some technology responses for processing complex arsenic-containing materials.30, 31 Most of these technologies have been developed to process high-arsenic …

Various pyrometallurgical methods for treating copper concentrates that contain appreciable arsenic are reviewed. Various aspects of the engineering of these treatment methods are discussed. The methods discussed include: complete oxidation with arsenic fixation;...

 — This method is typically not used for residential treatment because it requires frequent adjustments to optimize the process and remove all of the arsenic. 7 – Oxidation with filtration. Oxidation with …

 — Arsenic is trapped via precipitation, adsorption, and ion exchange mechanisms. Zero-valent iron, montmorillonite, and zeolites have been used as reactive …