Effect of arsenic concentration on microbial iron reduction and arsenic speciation in an iron-rich freshwater sediment

Objectives : Soil washing process has been widely applied for remediation of contaminated soil with arsenic and heavy metals in Korea. The application of soil washing could change physical and chemical properties of soils and metal speciation in soil, which could affect the risk to the environment and human health. Thus, it is necessary to evaluate metal and arsenic speciation and their mobility in soil after soil remediation in order to evaluate effectiveness of soil remediation process and manage soil quality effectively. The purpose of this study is to evaluate the risk of arsenic in soil after remediation of arsenic contaminated soil via soil washing.Methods : Arsenic contaminated soil collected at the abandoned mine site was washing with oxalic acid. The arsenic contaminated soil was divided into 2,000-500 µm, 500-250 µm, 250-150 µm, 150-75 µm, 75-38 µm, < 38 µm particle size fractions. After soil washing for each soil particle size fraction, arsenic speciation via sequential extraction and bioaccessibility in the soils were evaluated. Results and Discussion : Generally, arsenic and metal concentrations were higher in the soil fractions with smaller particle sizes. But high arsenic concentration was observed at the large particle size fractions (>250 µm), which might be due to the presence of mineral phases containing arsenic such as arsenolite or pyrite in the large particle size fraction soils. Sequential extraction showed that arsenic in mine soils was majorly present as associated with amorphous oxides. After soil washing with oxalic acid, arsenic in soils associated with amorphous oxides was greatly decreased, whereas the arsenic fraction associated sulfide and organic matter was increased. Soil washing decreased the bioaccessible arsenic concentration (mg/kg) in soil, but increased the bioaccessibility (%) depending on the soil characteristics. Conclusions : Soil washing changed arsenic species in soils, which affected mobility and risk of arsenic in soil.

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The contents of risk elements, arsenic speciation, and possible interactions of elements and betalains in beetroot (Beta vulgaris, L.) growing in contaminated soil

Open Life Sciences ◽

10.2478/s11535-010-0050-0 ◽

2010 ◽

Vol 5 (5) ◽

pp. 692-701 ◽

Cited By ~ 1

Author(s):

Jiřina Száková ◽

Jaroslav Havlík ◽

Barbora Valterová ◽

Pavel Tlustoš ◽

Walter Goessler

Keyword(s):

Beta Vulgaris ◽

Contaminated Soil ◽

Phosphate Buffer ◽

Arsenic Speciation ◽

Arsenic Concentration ◽

Dimethylarsinic Acid ◽

Total Arsenic ◽

Soil Arsenic ◽

Risk Element

AbstractThe effect of enhanced soil risk element contents on the uptake of As, Cd, Pb, and Zn was determined in two pot experiments. Simultaneously, transformation of arsenic and its compounds in beetroot (Beta vulgaris L.) plants was investigated. The mobile fractions of elements were determined in 0.05 mol L−1 (NH4)2SO4 extracts and did not exceed 2% of total soil arsenic, 9% of total cadmium, 3% of total lead, and 8% of total zinc, respectively. Although the soils were extremely contaminated the mobile portions of the elements represented only a small fragment of the total element content. Arsenic contents in beet plants reached up to 25 mg As kg−1 in roots and 48 mg As kg−1 in leaves in the soil characterized by the highest mobile arsenic portion. Arsenic portions extractable with water and phosphate buffer from the beetroot samples did not show significant differences between the extraction agents but the extractability was affected by the arsenic concentration. Arsenic was almost quantitatively extractable from the samples with the lowest total arsenic concentration, whereas in the samples with the highest total arsenic concentration less than 25% was extractable. Arsenate was the dominant arsenic compound in the extracts (70% in phosphate buffer, 50% in water extracts). A small portion of dimethylarsinic acid, not exceeding 0.5%, was detected only in the sample growing in the soil with the highest arsenic concentration. The role of betalains (betanin, isobetanin, vulgaxanthin I and vulgaxanthin II) in transformation/detoxification of arsenic in plants was not confirmed in this experiment because the plants were able to grow in the contaminated soil without any symptoms of arsenic toxicity.

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Predominant microbial iron reduction in sediment in early Cambrian sulfidic oceans

Global and Planetary Change ◽

10.1016/j.gloplacha.2021.103637 ◽

2021 ◽

pp. 103637

Author(s):

Chaochao Xing ◽

Xianguo Lang ◽

Haoran Ma ◽

Yang Peng ◽

Yongbo Peng ◽

...

Keyword(s):

Iron Reduction ◽

Early Cambrian ◽

Microbial Iron Reduction

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Breathing Iron: Molecular Mechanism of Microbial Iron Reduction byShewanella oneidensis

Manual of Environmental Microbiology ◽

10.1128/9781555818821.ch5.2.1 ◽

2015 ◽

pp. 5.2.1-1-5.2.1-13 ◽

Cited By ~ 3

Author(s):

Rebecca E. Cooper ◽

Jennifer L. Goff ◽

Ben C. Reed ◽

Ramanan Sekar ◽

Thomas J. Dichristina

Keyword(s):

Molecular Mechanism ◽

Iron Reduction ◽

Microbial Iron Reduction

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Sorption of linear alkylbenzene sulfonate to soil components and effects on microbial iron reduction

Environmental Toxicology and Chemistry ◽

10.1002/etc.5620220606 ◽

2003 ◽

Vol 22 (6) ◽

pp. 1221-1228 ◽

Cited By ~ 21

Author(s):

Inge Broberg Kristiansen ◽

Hubert de Jonge ◽

Per Nørnberg ◽

Ole Mather-Christensen ◽

Lars Elsgaard

Keyword(s):

Iron Reduction ◽

Linear Alkylbenzene Sulfonate ◽

Linear Alkylbenzene ◽

Microbial Iron Reduction ◽

Alkylbenzene Sulfonate ◽

Soil Components

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Kinetic characterization on reductive reactivity of iron(III) oxides in surface sediments of the East China Sea and the influence of repeated redox cycles: Implications for microbial iron reduction

Applied Geochemistry ◽

10.1016/j.apgeochem.2014.01.001 ◽

2014 ◽

Vol 42 ◽

pp. 16-26 ◽

Cited By ~ 11

Author(s):

Mao-Xu Zhu ◽

Liang-Jin Chen ◽

Gui-Peng Yang ◽

Chang-Qing Fan ◽

Tie Li

Keyword(s):

East China Sea ◽

Iron Reduction ◽

Surface Sediments ◽

East China ◽

Kinetic Characterization ◽

The East China Sea ◽

China Sea ◽

Redox Cycles ◽

Microbial Iron Reduction

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Arsenic cycling in freshwater phytoplankton and zooplankton cultures

Environmental Chemistry ◽

10.1071/en14039 ◽

2014 ◽

Vol 11 (5) ◽

pp. 496 ◽

Cited By ~ 8

Author(s):

G. Caumette ◽

I. Koch ◽

K. House ◽

K. J. Reimer

Keyword(s):

Inductively Coupled Plasma ◽

Arsenic Speciation ◽

Arsenic Concentration ◽

Inorganic Arsenic ◽

Contaminated Sediments ◽

Trophic Levels ◽

Artificial Lake ◽

X Ray ◽

Freshwater Phytoplankton ◽

Freshwater Plankton

Environmental context Understanding how arsenic is changed from toxic to non-toxic chemical forms in lakes and rivers is important in understanding the overall risk from arsenic. Freshwater plankton exposed in laboratory cultures to different sources of toxic inorganic arsenate formed arsenosugars, but at higher exposure levels, in water and through contaminated sediment, inorganic arsenate remained unchanged. In arsenic-contaminated freshwater bodies, plankton may provide a source of toxic inorganic arsenic to consumers. Abstract Freshwater phytoplankton (Chlamydomonas) and zooplankton (Daphnia pulex) were exposed to arsenic to trace the arsenic transformations and the formation of organoarsenic compounds at the base of the freshwater food chain. Plankton were cultured in artificial lake water, and exposed to arsenic through several pathways, hypothesised to be the main exposure sources: through water, food and contaminated sediments. High performance liquid chromatography–inductively coupled plasma–mass spectrometry and X-ray absorption spectroscopy were used to determine arsenic speciation in the studied organisms, and X-ray fluorescence mapping was used to locate the arsenic in a single Daphnia specimen. The results show that the formation of methylated arsenic compounds and arsenosugars by the zooplankton organisms was independent of the exposure route, but instead dependent on arsenic concentration in the environment. Specifically, organoarsenic compounds were dominant in extracts of Daphnia organisms exposed to low arsenic concentrations through water at 10µgL–1 (67%), and through contaminated food (75%), but inorganic arsenic was dominant in Daphnia exposed to high arsenic concentrations, including contaminated sediments. Phytoplankton cultures contained variable amounts of arsenosugars, but on average the dominant compound in phytoplankton was inorganic arsenic. The main implications of the present study for understanding arsenic cycling in the freshwater plankton community are that arsenosugars are formed at possibly both the phytoplankton and zooplankton trophic levels; and that higher arsenic loads in plankton correspond to higher inorganic arsenic concentrations, which could indicate a saturation of the arsenic methylation process by plankton organisms.

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Nanosized Iron Oxide Colloids Strongly Enhance Microbial Iron Reduction

Applied and Environmental Microbiology ◽

10.1128/aem.00417-09 ◽

2009 ◽

Vol 76 (1) ◽

pp. 184-189 ◽

Cited By ~ 67

Author(s):

Julian Bosch ◽

Katja Heister ◽

Thilo Hofmann ◽

Rainer U. Meckenstock

Keyword(s):

Iron Oxide ◽

Iron Oxides ◽

Iron Reduction ◽

Colloidal Suspension ◽

Microbial Reduction ◽

Geobacter Sulfurreducens ◽

Hydrodynamic Diameter ◽

Colloidal Iron ◽

Surface Areas ◽

Microbial Iron Reduction

ABSTRACT Microbial iron reduction is considered to be a significant subsurface process. The rate-limiting bioavailability of the insoluble iron oxyhydroxides, however, is a topic for debate. Surface area and mineral structure are recognized as crucial parameters for microbial reduction rates of bulk, macroaggregate iron minerals. However, a significant fraction of iron oxide minerals in the subsurface is supposed to be present as nanosized colloids. We therefore studied the role of colloidal iron oxides in microbial iron reduction. In batch growth experiments with Geobacter sulfurreducens, colloids of ferrihydrite (hydrodynamic diameter, 336 nm), hematite (123 nm), goethite (157 nm), and akaganeite (64 nm) were added as electron acceptors. The colloidal iron oxides were reduced up to 2 orders of magnitude more rapidly (up to 1,255 pmol h− 1 cell− 1) than bulk macroaggregates of the same iron phases (6 to 70 pmol h− 1 cell− 1). The increased reactivity was not only due to the large surface areas of the colloidal aggregates but also was due to a higher reactivity per unit surface. We hypothesize that this can be attributed to the high bioavailability of the nanosized aggregates and their colloidal suspension. Furthermore, a strong enhancement of reduction rates of bulk ferrihydrite was observed when nanosized ferrihydrite aggregates were added.

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