Fractionation and speciation of arsenic in fresh and combusted coal wastes from Yangquan, northern China

Abstract

In this study, the content and speciation of arsenic in coal waste and gas condensates from coal waste fires were investigated, respectively, using the digestion and sequential extraction methods. The fresh and fired-coal waste samples were collected from Yangquan, which is one of the major coal production regions in northern China. High-performance liquid chromatography-inductively coupled plasma-mass spectrometry (HPLC-ICP-MS) was used to determine the concentrations of four major arsenic species [As(III), As(V), monomethylarsonic acid (MMA) and dimethylarsenic acid (DMA)] in the extracts, while ICP-MS was used to measure total As content. Arsenic content in the investigated coal wastes and the condensate ranges between 23.3 and 69.3 mg/kg, which are higher than its reported average content in soils. Arsenic in coal waste exists primarily in the residual fraction; this is followed in decreasing order by the organic matter-bound, Fe-Mn oxides-bound, exchangeable, carbonates-bound, and water-soluble fractions. The high content of arsenic in the condensates indicates that combustion or spontaneous combustion is one of the major ways for arsenic release into the environment from coal waste. About 15% of the arsenic in the condensate sample is labile and can release into the environment under leaching processes. The water extractable arsenic (WEA) in the fresh coal waste, fired coal wastes, and the condensate varied between 14.6 and 341 μg/kg, with As(V) as the major species. Furthermore, both MMA and DMA were found in fresh coal wastes, fired coal wastes, and the condensate.

Arsenic relative bioavailability from diet and airborne exposures: Implications for risk assessment

“…In 81 field leachate samples collected from 29 coal combustion product management sites, As concentrations in ash leachate ranged from 1.4 to 1380 μg/L with a median of 25 μg/L (EPRI, 2006). Of interest from a toxicological standpoint is that As in coal combustion ash has been found to be composed mainly (90-97%) of As V species (Goodarzi and Huggins, 2001;Huggins et al, 2004Huggins et al, , 2007Narukawa et al, 2005;EPRI, 2006EPRI, , 2008aWang et al, 2008;Bednar et al, 2010;Gao et al, 2012;Catalano et al, 2012). As V species (arsenate) are known to be considerably less acutely toxic to mammalian receptors than As III (arsenite) species (Styblo et al, 2000;Naranmandura et al, 2011).…”

A Review of Groundwater Arsenic Contamination in Bangladesh: The Millennium Development Goal Era and Beyond

“…Arsenic poisoning via groundwater contamination has been driven by deliberate changes in human behavior. For example, combustion of coal releases arsenic from coal waste products into the environment through the process of leaching [ 3 ]. To date, there has been a paucity of conducted studies that focus on developing suitable solutions for managing arsenic contamination, thereby, the problem of access to safe drinking water persists.…”

Behavior of Metals in a Combined Wastewater Collection System in Ostrava, Czech Republic

“…Origin of Metals in an Urban Wastewater Collection System. Urban contamination also has multiple sources, including road, roof runoff and water leaching from soils and landfills (Förster, 1996;Thévenot et al, 2007, Carbonell et al, 2011Gao et al, 2012), resulting in high metal loads in urban stormwater. Domestic and industrial sources of metals are numerous, and the urban wastewater collection systems that generally collect industrial wastewater are a major metal contamination source in densely populated areas (Sörme and Lagerkvist, 2002).…”