Role of organic matter in framboidal pyrite oxidation

Rigby, Portia; Dobos, S. K.; Cook, F. J.; Goonetilleke, Ashantha

doi:10.1016/j.scitotenv.2004.10.011

Cited by 40 publications

(16 citation statements)

References 15 publications

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“…In this study, the limited oxygen concentration in the influent and the long-term flooding operation created low redox conditions in the microcosms (-200 ~ 50 mV), which may have decreased the pyrite oxidation rates (Johnston et al, 2014). Furthermore, the organic carbon released by the litter could also compete with the reduced S for oxygen, thereby slowing pyrite oxidation (Rigby et al, 2006). In addition to pyrite, some metastable iron sulfides (e.g.…”

Section: Sulfate Transformation In Cwsmentioning

confidence: 89%

Sulfate removal and sulfur transformation in constructed wetlands: The roles of filling material and plant biomass

et al. 2016

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Sulfate in effluent is a challenging issue for wastewater reuse around the world. In this study, sulfur (S) removal and transformation in five batch constructed wetlands (CWs) treating secondary effluent were investigated. The results showed that the presence of the plant cattail (Typha latifolia) had little effect on sulfate removal, while the carbon-rich litter it generated greatly improved sulfate removal, but with limited sulfide accumulation in the pore-water. After sulfate removal, most of the S was deposited with the valence states S (-II) and S (0) on the iron-rich gravel surface, and acid volatile sulfide was the main S sink in the litter-added CWs. High-throughput pyrosequencing revealed that sulfate-reducing bacteria (i.e. Desulfobacter) and sulfide-oxidizing bacteria (i.e. Thiobacillus) were dominant in the litter-added CWs, which led to a sustainable S cycle between sulfate and sulfide. Overall, this study suggests that recycling plant litter and iron-rich filling material in CWs gives an opportunity to utilize the S in the wastewater as both an electron acceptor for sulfate reduction and as an electron donor for nitrate reduction coupled with sulfide oxidation. This leads to the simultaneous removal of sulfate, nitrate, and organics without discharging toxic sulfide into the receiving water body.

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Section: Sulfate Transformation In Cwsmentioning

confidence: 89%

Sulfate removal and sulfur transformation in constructed wetlands: The roles of filling material and plant biomass

et al. 2016

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“…Different origins have been inferred for framboidal pyrite crystals, including a purely inorganic origin, based on laboratory synthesis and occurrences in magmatic rocks, framboid formation through indirect biogenic processes, and a direct biogenic process of framboid formation [23,34,28,35,36,37]. Occurrence of the studied framboidal pyrite crystals in close association with biodegraded oils in the pores of the oil sands suggests that they were formed as part of the biodegradation processes that occurred in the oil sands.…”

Section: Discussionmentioning

confidence: 98%

Common Occurrences of Authigenic Pyrite Crystals in Cretaceous Oil Sands as Consequence of Biodegradation Processes

Bata¹,

Samaila²,

Maigari³

et al. 2017

Geol. behav.

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Ten (10) Cretaceous oil sands from different localities around the world were studied with the aim of reporting the common occurrence of authigenic pyrite crystals in them. The observed pyrite crystals (both framboid and euhedral) are restricted to the pore spaces of the studied oil sands, in close association with biodegraded oils and other authigenic minerals. Diagenetic processes in one of the studied samples triggered the transformation of framboidal pyrite crystals to octahedral pyrite crystals. This study demonstrates that geological conditions/ processes that lead to the formation of authigenic pyrite crystals in sandstones are those that favour biodegradation. Potentially, these conditions include occurrence at shallow depths (< 2000 m), moderate reservoir temperatures that can support microbial life (temperature < 80° C), availability of micro-organisms that are capable of degrading oils in the reservoir, nutrient availability (e.g., iron, nitrogen, potassium, and phosphorus), and oil volume in the reservoir. Studied framboidal pyrite crystals were observed to occur within confined spaces. The oils (organic matter) associated with the studied samples are believed to have played an important role of providing the source of spherule moulds for framboid pseudomorphs and aided the stabilization of the gel in which the framboid crystals were protected. TIC fragmentograms of the saturate fractions of the oils extracted from the studied oil sands show progressive depletion of chromatographically resolved hydrocarbons (e.g. n-alkanes, acyclic isoprenoid alkanes; alkyl benzenes, naphthalenes and phenanthrenes) relative to the unresolved hydrocarbon mixture, forming unresolved complex mixture (UCM) humps, consistent with oils that have undergone biodegradation.

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“…Our results suggested that techniques based on short‐term sulphide oxidation are not effective and likely to be unreliable in soils containing large percentages of organic matter. The slower rate of pH decrease and the final values obtained in the surface samples suggest retardation in the rate and amount of acid generation by pyrite oxidation because of the concurrent oxygen consumption by organic matter and bacterial activity (Rigby et al. , 2006).…”

Section: Discussionmentioning

confidence: 99%

“…Diverse field techniques and evidence have been traditionally applied acidsulphate soil identification (Dent & Dawson, 1998;Dear et al, 2002;Ahern et al, 2004) and it has become apparent that the characteristics of these soils are area dependent the, results obtained in soils of one area cannot necessarily be extrapolated to similar soils elsewhere, and that none of the simple identification techniques should be employed alone (Thomas & Varley, 1982;Andriesse, 1993). More recently, Rigby et al (2006) criticized the lack of actual rates for 'in situ' pyrite oxidation and hence acid generation rates, to support the construction of worst-case scenarios of the environmental risk of acid-sulphate soils.…”

Section: Introductionmentioning

confidence: 99%

A critical examination of some common field tests to assess the acid‐sulphate condition in soils

Vegas-Vilarrúbia¹,

Baritto

Meleán

2007

Soil Use and Management

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Acid-sulphate soils are of major environmental concern in many wetlands. Severe acidification episodes have occurred worldwide because of the oxidation of iron sulphides to sulphuric acid by human activities, and diverse techniques have been set up to determine the presence of acid-sulphate soils. This paper evaluates the usefulness of four common easy-to-apply field survey tests for potential acidsulphate diagnosis in some Histosols and Entisols in wetlands: incomplete oxidation by fast air-drying, incubation, fast oxidation with hydrogen peroxide, and the indirect determination of sulphide with lead acetate. Samples of 227 surface-organic and underlying mineral soils of poorly drained Histosols and Entisols of the Orinoco river delta plain were tested. Results showed that for highly organic samples the interpretation of results obtained from the acid-sulphate soil tests may be misleading, because they cannot be unambiguously related to the production of sulphuric acid derived from pyrite oxidation. Mineral samples yielded more reliable results. The incomplete oxidation by fast air-drying test did not induce significant acidification either in organic or in mineral samples; the final pH values were dependent on the original pH values. The fast oxidation with hydrogen peroxide test was effective with mineral samples. During the incubation test, the slower rate of pH decrease and the final values obtained with the organic samples suggested retardation in the rate and amount of acid generation by pyrite oxidation because of the concurrent oxygen consumption by organic matter and bacterial activity. The indirect determination of sulphide with lead acetate yielded only qualitative results in organic samples, but worked well in mineral samples, indicating a higher content of pyrite intermediates. Effective estimation of the actual presence and potential for acidification of soil is important, in order to avoid excessive or inappropriate amelioration techniques to prevent acid production.

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Role of organic matter in framboidal pyrite oxidation

Cited by 40 publications

References 15 publications

Sulfate removal and sulfur transformation in constructed wetlands: The roles of filling material and plant biomass

Sulfate removal and sulfur transformation in constructed wetlands: The roles of filling material and plant biomass

Common Occurrences of Authigenic Pyrite Crystals in Cretaceous Oil Sands as Consequence of Biodegradation Processes

A critical examination of some common field tests to assess the acid‐sulphate condition in soils

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