Soil humic acids may favour the persistence of hexavalent chromium in soil

Leita, L.; Margon, Alja; Pastrello, Arnold; Arčon, Iztok; Contin, Marco; Mosetti, Davide

doi:10.1016/j.envpol.2009.01.020

Cited by 64 publications

(21 citation statements)

References 37 publications

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“…Many different spectroscopic techniques have been used to study the HA structure and their interaction with xenobiotics such as: fluorescence spectroscopy (D'Orazio and Miano 2016), NMR (Huang et al 2012), ESP (Pandey et al 1999), infrared spectroscopy (Senesi et al 1995), and UV-visible spectroscopy (Leita et al 2009). …”

Section: Introductionmentioning

confidence: 99%

Studying of the interaction between peat humic acids and metazachlor using spectroscopy methods

et al. 2018

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Purpose The analysis covered the interaction of humic acids (HA) isolated from peats with the metazachlor using spectroscopic methods. Materials and methods Five peatlands have been selected for the study in the southern and northern parts of Poland. Extraction of humic acids (HA1, HA2, HA3, HA4, and HA5) was performed using a procedure recommended by the International Humic Substances Society. Metazachlor 500 SC with metazachlor as a biologically active substance [2-chloro-N-(pyrazol-1-ylmethyl)acet-2′,6′-xylidide] has been used. HA have been assessed on the basis of their elemental composition. Spectroscopic techniques have been used to study the HA structure and their interaction with metazachlor including: UVvisible spectroscopy, dynamic light scattering, and delayed luminescence (DL) Results and discussion Based on their morphological and chemical properties, the studied peat soils can be classified as follows: (1) Eutric Murshic Sapric Histosols, (2) Eutric Sapric Histosols, (3) Eutric Hemic Histosols, (4) Eutric Fibric Histosols, and (5) Dystric Dranic Hemic Histosols according to the WRB guidelines (2015). Results showed that the largest particle size, measured by E 4/6 coefficient, was found in HA2 sample, while the smallest in HA3 sample. The addition of metazachlor to HA solutions reduced the values of E 4/6 coefficient by 33 to 72%, while the values of hydrodynamic diameter by 4 to 32%. No significant changes were found between E 4/6 after adding of metazachlor to HA solutions. The largest changes in DL intensity, excited both by blue and red light after herbicide addition, were observed in HA2 sample, which is characterized by the largest particle size, the highest oxygen content and CQ value as well as the lowest Baromatization rate^value. Conclusions The particle sizes of HA molecules measured by E 4/6 coefficient do not impact on the particle sizes of HA-herbicide systems measured by the same ratio. The delayed luminescence may become valuable, because it is simple, fast, and sensitive. Additionally, the results show minor errors comparing with chemical methods. This method may provide information about structure and nature of humic acids, as well as their photoreactivity. The using of delayed luminescence in studies of HApesticides interaction may enable us to better understand the luminescence properties of HA.

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Section: Introductionmentioning

confidence: 99%

Studying of the interaction between peat humic acids and metazachlor using spectroscopy methods

et al. 2018

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“…This could be due to the increase of DO during postmonsoon periods which could have effectively inhibited the Cr(VI) reduction by oxidizing Fe(II). Likewise, the temporal changes in the distribution of Cr(VI) and Cr ( (Hwang et al 2002), stabilization of Cr(VI) by soil humic matter (Leita et al 2009) etc. could partly been responsible for the anomalies observed, but could not be established from this study.…”

Section: Importance Of Groundwater Do Concentration On Chromium Specimentioning

confidence: 98%

Chromium speciation in a contaminated groundwater: redox processes and temporal variability

Kumar

Riyazuddin

2010

Environ Monit Assess

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Chromium species (Cr(III), Cr(VI), and Cr(III)-organic) in groundwater of a tannery contaminated area were monitored during pre- and post-monsoon seasons for a period of 3 years (May 2004 to January 2007). The objectives of the study were (1) to investigate the temporal variation of chromium species and other matrix constituents and (2) to study the redox processes associated with the temporal variation of chromium species. Samples were collected from 15 dug wells and analyzed for chromium species and other constituents. The results showed that the groundwater was relatively more oxidizing during post-monsoon periods than the pre-monsoon periods. Except one sample, the concentration of chromium species were found in the order of Cr(VI)>Cr(III)>Cr(III)-organic complexes during all the pre- and post-monsoon periods. In most of the wells, the concentrations of Cr(III), Cr(VI), and Cr(III)-organic decreased during post-monsoon periods compared to their pre-monsoon concentrations. However, the Cr(VI)/Cr(Total) ratio still increased and the Cr(III)/Cr(Total) ratio decreased during post-monsoon periods in most of the samples. The possible mechanisms for the temporal variation of chromium species were (1) Fe(II) reduction of Cr(VI) vs oxidation of Fe(II) by dissolved oxygen and (2) oxidation of Cr(III) by Mn(IV).

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“…Considering heavy metals, the passage from unavailable to available form is regulated by chemical, physical and biological conditions and time, which determine the transfer of metals from the solid to the solution phase that are governed by properties such as pH, organic matter and clay content, cation exchange capacity redox potential etc. (Leita et al, 2009). …”

Section: Processes Of Bioavailability In Soilmentioning

confidence: 99%

Considering bioavailability in the remediation of heavy metal contaminated sites

Leita

Petruzzelli

Pedron

et al. 2013

E3S Web of Conferences

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Abstract.Many years of research have demonstrated that instead of the total concentration of metals in soil, bioavailability is the key to understand the environmental risk derived by metals, since adverse effects are related only to the biologically available forms of these elements. The knowledge of bioavailability can decrease the uncertainties in evaluating exposure in human and ecological risk assessment. At the same time, the efficiency of remediation treatments could be greatly influenced by availability of the contaminants. Consideration of the bioavailability processes at contaminated sites could be useful in site-specific risk assessment: the fraction of mobile metals, instead of total content should be provided as estimates of metal exposure. Moreover, knowledge of the chemical forms of heavy metals in soils is a critical component in the evaluation of applicability of different remediation technologies such as phytoremdiation or soil washing.

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Soil humic acids may favour the persistence of hexavalent chromium in soil

Cited by 64 publications

References 37 publications

Studying of the interaction between peat humic acids and metazachlor using spectroscopy methods

Studying of the interaction between peat humic acids and metazachlor using spectroscopy methods

Chromium speciation in a contaminated groundwater: redox processes and temporal variability

Considering bioavailability in the remediation of heavy metal contaminated sites

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