SEGH Articles

Fate of smelter dusts in soils

14 October 2016
Winner of the best poster prize at the SEGH meeting in Brussels. Alice Jarosikova, PhD student from Charles University in Prague, describes her research on fate of smelter-derived dust particles in soils.

Areas in the vicinity of metal smelters are inevitably exposed to metal(loid)-bearing particulates, which are emitted and dispersed in the environmental compartments. Especially surrounding soils represent an important sink for the most of these anthropogenic emissions.

 

1. Dust emitted from the copper smelter

The main objective of our study is to identify the fate of smelter dusts when deposited in soils as well as to clarify subsequent dynamics of smelter-related contaminants in the soil systems, which can interact with water and biota. We use a long-term in situ experimental approach, where polyamide bags filled with smelter dusts are placed for incubation into different depths of soil profiles. Our current 4-year in situ experiment has been initiated in October 2013 in four contrasting soil types and under different vegetation covers using the methodology described by Ettler et al. (2012). We have compared the weathering rates of smelter dusts in the following soils: neutral-to-alkaline Chernozem developed on loess (grass cover), neutral-to-slightly acidic Cambisol (grass cover), and acidic Cambisols developed under the beech and spruce forests. Our study materials are (i) arsenic rich fly ash (composed mostly of arsenolite, As2O3, galena, PbS and gypsum, CaSO4·2H2O) and (ii) copper slag (enriched in Cu, Zn and Pb). We collect experimental bags each 6 months and soil columns are vertically sampled (each 5 cm of depth) using physical rings and when possible, soil pore water is collected using Rhizon samplers. We perform mineralogical analysis on smelter dusts (to identify changes in phase composition), supplemented with bulk chemistry of dusts and soil samples coupled to As speciation analysis in soil pore waters and extracts.

 

2. Soil sampling after the smelter dust incubation using physical rings

Despite the fact that our field experiment is just in the middle and data collection is still in progress, we find that fly ash particles are highly reactive in soil systems and their dissolution is increasing over time. Arsenic leaching associated with the highest fly ash dissolution was the most significant in soil developed under the beech forest mainly due to specific seepage conditions leading to more rapid flush regime (higher moisture than for other soil types). Observation under the scanning electron microscopy (SEM) indicated that the fly ash incubated in soil under the beech was the most weathered with etched arsenolite surfaces and secondary formation of a complex metal-bearing arsenate phase.

Field experimental studies are always more difficult than laboratory investigations, because a number of parameters cannot be fully controlled. However, they are more suitable for understanding complex processes in real-life scenarios. We are looking forward to the next sampling campaign in October 2016 J

Alice Jarošíková

PhD candidate at Institute of Geochemistry, Mineralogy and Mineral Resources, Faculty of Science, Charles University in Prague, Czech Republic

Reference:

Ettler, V., Mihaljevič, M., Šebek, O., Grygar, T., Klementová, M., 2012. Experimental in situ transformation of Pb smelter fly ash in acidic soils. Environ. Sci. Technol. 46, 10539-10548.

 

Keep up to date

SEGH Events

Submit Content

Members can keep in touch with their colleagues through short news and events articles of interest to the SEGH community.

Science in the News

Latest on-line papers from the SEGH journal: Environmental Geochemistry and Health

  • Status, source identification, and health risks of potentially toxic element concentrations in road dust in a medium-sized city in a developing country 2017-09-19

    Abstract

    This study aims to determine the status of potentially toxic element concentrations of road dust in a medium-sized city (Rawang, Malaysia). This study adopts source identification via enrichment factor, Pearson correlation analysis, and Fourier spectral analysis to identify sources of potentially toxic element concentrations in road dust in Rawang City, Malaysia. Health risk assessment was conducted to determine potential health risks (carcinogenic and non-carcinogenic risks) among adults and children via multiple pathways (i.e., ingestion, dermal contact, and inhalation). Mean of potentially toxic element concentrations were found in the order of Pb > Zn > Cr(IV) > Cu > Ni > Cd > As > Co. Source identification revealed that Cu, Cd, Pb, Zn, Ni, and Cr(IV) are associated with anthropogenic sources in industrial and highly populated areas in northern and southern Rawang, cement factories in southern Rawang, as well as the rapid development and population growth in northwestern Rawang, which have resulted in high traffic congestion. Cobalt, Fe, and As are related to geological background and lithologies in Rawang. Pathway orders for both carcinogenic and non-carcinogenic risks are ingestion, dermal contact, and inhalation, involving adults and children. Non-carcinogenic health risks in adults were attributed to Cr(IV), Pb, and Cd, whereas Cu, Cd, Cr(IV), Pb, and Zn were found to have non-carcinogenic health risks for children. Cd, Cr(IV), Pb, and As may induce carcinogenic risks in adults and children, and the total lifetime cancer risk values exceeded incremental lifetime.

  • Erratum to: Preliminary assessment of surface soil lead concentrations in Melbourne, Australia 2017-09-11
  • In vivo uptake of iodine from a Fucus serratus Linnaeus seaweed bath: does volatile iodine contribute? 2017-09-02

    Abstract

    Seaweed baths containing Fucus serratus Linnaeus are a rich source of iodine which has the potential to increase the urinary iodide concentration (UIC) of the bather. In this study, the range of total iodine concentration in seawater (22–105 µg L−1) and seaweed baths (808–13,734 µg L−1) was measured over 1 year. The seasonal trend shows minimum levels in summer (May–July) and maximum in winter (November–January). The bathwater pH was found to be acidic, average pH 5.9 ± 0.3. An in vivo study with 30 volunteers was undertaken to measure the UIC of 15 bathers immersed in the bath and 15 non-bathers sitting adjacent to the bath. Their UIC was analysed pre- and post-seaweed bath and corrected for creatinine concentration. The corrected UIC of the population shows an increase following the seaweed bath from a pre-treatment median of 76 µg L−1 to a post-treatment median of 95 µg L−1. The pre-treatment UIC for both groups did not indicate significant difference (p = 0.479); however, the post-treatment UIC for both did (p = 0.015) where the median bather test UIC was 86 µg L−1 and the non-bather UIC test was 105 µg L−1. Results indicate the bath has the potential to increase the UIC by a significant amount and that inhalation of volatile iodine is a more significant contributor to UIC than previously documented.