Research articleEvaluating Cr behaviour in two different polluted soils: Mechanisms and implications for soil functionality
Graphical abstract
Introduction
Chromium is a transition metal with anticorrosive properties, it is widely used in many industrial applications including metallurgy, stainless-steel production, electroplating, leather tanning, wood preservation, ceramics glazes, paints and pulp and paper production (Jobby et al., 2018; Shahid et al., 2017). Solid and liquid wastes from these industries are considered major sources of Cr pollution in soils (Shahid et al., 2017). Besides this, atmospheric deposition and the use of fertilizers (phosphorus fertilizers and biosolids) also contributes to increase Cr concentration in soils (Borges et al., 2015; Nicholson et al., 2003; Vogel et al., 2015). Given this context, concern about Cr pollution in soils is gaining significant attention since it can potentially cause human health problems by entering the food chain (Ahmed et al., 2016), through soil dust inhalation (Broadway et al., 2010) or the transfer to ground and surface waters (Hausladen et al., 2018; Paustenbach et al., 2003).
The most common oxidation states of Cr in the environment are Cr(III) and Cr(VI). Cr(VI) is an oxyanion, it is found forming soluble forms in soils so it can be easily leached into the groundwater or be absorbed by plants. It possesses a high oxidation power causing severe oxidative injuries and DNA damage on living organisms. In humans, it is classified as carcinogen of Group A (USEPA, 1998). Cr(III) is between 10 and 100 times less toxic than Cr(VI) (De Flora et al., 1990). It is mainly found as cation, forming insoluble forms that are adsorbed to the negatively charged particles of soils, or precipitated as oxides and hydroxides.
Some biological (e.g. oxalic, citric and humic acids) and synthetic (e.g. EDTA) chelating agents can, however, form Cr(III) soluble complexes (Bartlett, 2014; Carbonaro et al., 2008; Saad et al., 2017). About 35% of the Cr that arrives to soils from anthropogenic activities is Cr(VI) (Dhal et al., 2013). Soil organic matter (SOM) plays as an electron donor to reduce Cr(VI) to Cr(III), this process is also controlled by other soil characteristics such us texture, pH or cation exchange capacity (Bartlett, 2014; Shahid et al., 2017; Taylor et al., 2000). However, the quantity of Cr(VI) coming from anthropogenic activities could overcome soil redox buffering capacity.
Besides the above-mentioned risks to human health, the presence of Cr in soils can impair soil ecological services such as nutrient cycling, carbon storage or water cycling. The establishment of a vegetation cover in polluted soils can be a strategy to improve soil structure and to reduce soil erosion and pollutant mobilization helping in the recovery of these services (Burges et al., 2018; Vangronsveld et al., 2009). In this sense, previous studies showed the intrinsic tolerance of Silene vulgaris (Moench) Garcke to high levels of Cr (Pradas del Real et al., 2014, 2016) and its ability to shape the structure of rhizosphere microorganism community in Cr polluted soils (García-Gonzalo et al., 2017b, 2017a).
In order to assess the risk associated with Cr soil pollution and to develop adequate soil managing strategies, it is important to understand the processes governing Cr behavior in soils. In general, the risk assessment of a contaminated site uses data of total metal concentration (Kumpiene et al., 2017). However, these data provide limited information on the impact of the pollutant on soil biota. Metal bioavailability, which refers to the accessible fraction that could be absorbed by living organisms, it is being considered a better indicator to evaluate the risk (Kumpiene et al., 2017). This is especially relevant in the case of Cr, as its availability strongly changes with speciation.
Recent studies have investigated the role of soil components on redox, complexation and adsorption reactions of Cr with special attention to the role of humic acids (HA) (Huang et al., 2012; Ohta et al., 2012; Wu et al., 2017; Zhang et al., 2018) and Fe (oxy) hydroxides (Hori et al., 2015; Saad et al., 2017; Whitaker et al., 2018). By using Fourier Transform Infrared Spectroscopy (FTIR), Wen et al. (2018) showed that different soil organic matter (SOM) functional groups are implicated in Cr(III) complexation in rhizospheric and non rhizospheric soils. Veselská et al. (2019) investigated the redox and adsorption reactions of Cr(VI) in synthetic mixtures of silicates, clays, oxides and humic acids. The authors tested different Cr(VI) concentrations, pH, background electrolyte concentrations and sorbate/sorbent ratios and they combined results from mechanistic surface complexation modelling with experimental spectroscopic and isotopic analysis. The study concluded that soils rich in organic matter and clay minerals would be more efficient in Cr(VI) reduction and Cr(III) retention but that complex combination of factors, particularly the presence of Fe(oxy)hydroxides can lead to very different scenarios. Although they provide significant mechanistic information, the above-mentioned studies used model batch systems based on isolated synthetic or extracted soil components. There is then a lack of mechanistic studies in more realistic experimental systems.
The objectives of the present study were: i) to investigate the mechanisms explaining Cr speciation and bioavailability in artificially polluted soils after a long pot experiment and, ii) to evaluate their influence on the recovery of the soil functions related with biological quality and plant growth. To this end, two soils with contrasting characteristics were polluted with either a Cr(VI) solution, to simulate pollution from wastewaters and mine and industrial effluents; or with a sewage sludge from a wastewater treatment plant, as an example of solid industrial waste containing Cr. S. vulgaris was grown in these soils for 21 months. An exhaustive sampling and multivariate analysis were developed to ensure the robustness of the results.
Section snippets
Soil characterization and pollution process
Two soils from Madrid region (Spain) were investigated in this study: Soil A (El Escorial: 40,579140; 4,129067) and soil B (Alcala de Henares: 40,521987; 3,288817). For their characterization, soil samples were air dried, disaggregated and sieved (<2 mm) and then analyzed according to the official Spanish methodology for soil analysis (MAPA (Ministerio de Agricultura Pesca y Alimentación), 1994). Metal concentrations were determined after acid mineralization as described in supporting
Soil and biological quality variables
Considering the large number of variables in our experimental system that may affect the biological activity of soils and plant growth, we seek to identify the main soil factors describing the variability of the experimental data set. Due to the high correlation among studied variables, PCA did not allowed to identify the main variables (data not shown). We then applied Logistic Regression Model using LASSO estimator. From the twenty soil variables investigated in this study, the following nine
Discussion
In the present study Cr bioavailability has been determined in two soils with contrasting characteristics 21 months after being polluted with either an industrial sewage sludge or Cr(VI) solution. Cr concentration has been determined in the soil pore water, which has been previously shown to be an adequate method for the quantification of the Cr bioavailable fraction in soils (Choppala et al., 2013). Although total Cr concentrations were similar in both soils and Cr treatments, significant
Conclusions
This study shows the role of specific functional groups of SOM and other soil components in Cr redox and adsorption reactions in two soils polluted with Cr(VI) solution and an industrial sludge. The presence of these functional groups together with pH determine Cr speciation and bioavailability which strongly influence the recovery of the soil functions related with soil biological activity and plant growth 21 months after pollution. In calcareous soils, like soil B in this study, with pH > 7
CRediT authorship contribution statement
A.E. Pradas del Real: Methodology, Investigation, Formal analysis, Writing - original draft, Visualization. A. Pérez-Sanz: Conceptualization, Methodology, Supervision, Writing - review & editing. P. García-Gonzalo: Data curation, Validation, Writing - review & editing. H. Castillo-Michel: Software, Methodology, Data curation. M.J. Gismera: Investigation, Validation. M.C. Lobo: Conceptualization, Writing - review & editing, Supervision, Funding acquisition.
Declaration of competing interest
The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.
Acknowledgments
This work was supported by Projects SINCROPLANT (FP-18 IMIDRA) and REHABILITA CTM2016-78222-C2-1-R (AEI/FEDER, UE). Ana Pradas del Real thanks Atracción de Talento Program from Madrid Region. Authors want to thank Leticia Monico for providing Cr(OH)3 reference spectra and Marine Cotte for her advice in Cr XANES acquisition.
References (72)
- et al.
Modulation of hexavalent chromium toxicity on οriganum vulgare in an acidic soil amended with peat, lime, and zeolite
Chemosphere
(2018) - et al.
Method development for the determination of chromium and thallium in fertilizer samples using graphite furnace atomic absorption spectrometry and direct solid sample analysis
Microchem. J.
(2015) - et al.
Chemical fractionation and translocation of heavy metals in Canna indica L. grown on industrial waste amended soil
J. Hazard Mater.
(2008) - et al.
Determination of the bioaccessibility of chromium in Glasgow soil and the implications for human health risk assessment
Sci. Total Environ.
(2010) - et al.
Carboxylate-containing chelating agent interactions with amorphous chromium hydroxide: adsorption and dissolution
Geochem. Cosmochim. Acta
(2008) - et al.
Interactions of chromium with microorganisms and plants
FEMS Microbiol. Rev.
(2001) - et al.
Soil forensics: a spectroscopic examination of trace evidence
Microchem. J.
(2018) - et al.
Chemodynamics of chromium reduction in soils: implications to bioavailability
J. Hazard Mater.
(2013) - et al.
Genotoxicity of chromium compounds
A review. Mutat. Res. Genet. Toxicol.
(1990) - et al.
Chemical and microbial remediation of hexavalent chromium from contaminated soil and mining/metallurgical solid waste: a review
J. Hazard Mater.
(2013)
Factors affecting glucosidase and galactosidase activities in soils
Soil Biol. Biochem.
Ameliorative roles of melatonin and/or zeolite on chromium-induced leaf senescence in marjoram plants by activating antioxidant defense, osmolyte accumulation, and ultrastructural modification
Ind. Crop. Prod.
Surface reactions of chromium in soils and waters
Geoderma
Ecotoxicological assessment of doxycycline in aged pig manure using multispecies soil systems
Sci. Total Environ.
Phytoavailability of Cr in Silene vulgaris: the role of soil, plant genotype and bacterial rhizobiome
Ecotoxicol. Environ. Saf.
Heavy metals and soil microbes
Soil Biol. Biochem.
Reduction process of Cr(VI) by Fe(II) and humic acid analyzed using high time resolution XAFS analysis
J. Hazard Mater.
Chromate reduction on humic acid derived from a peat soil - exploration of the activated sites on HAs for chromate removal
Chemosphere
Biosorption and biotransformation of hexavalent chromium [Cr(VI)]: a comprehensive review
Chemosphere
Chromium occurrence in the environment and methods of its speciation
Environ. Pollut.
Assessment of methods for determining bioavailability of trace elements in soils: a review
Pedosphere
Bulk soil and rhizosphere bacterial community PCR--DGGE profiles and $β$-galactosidase activity as indicators of biological quality in soils contaminated by heavy metals and cultivated with Silene vulgaris (Moench) Garcke
Chemosphere
Biochemical parameters and bacterial species richness in soils contaminated by sludge-borne metals and remediated with inorganic soil amendments
Environ. Pollut.
Influence of sewage sludge application on physical and chemical properties of Gypsisols
Geoderma
An inventory of heavy metals inputs to agricultural soils in England and Wales
Sci. Total Environ.
Distribution, movement and plant availability of trace metals in soils amended with sewage sludge composts: application to low metal loadings
Sci. Total Environ.
Environmental chemistry of chromium
Sci. Total Environ.
Waste or substrate for metal hyperaccumulating plants — the potential of phytomining on waste incineration bottom ash
Sci. Total Environ.
Phytoextraction of Ni from a toxic industrial sludge amended with biochar
J. Geochem. Explor.
Chromium speciation, bioavailability, uptake, toxicity and detoxification in soil-plant system: a review
Chemosphere
The role of soil components in synthetic mixtures during the adsorption and speciation changes of Cr(VI): conjunction of the modeling approach with spectroscopic and isotopic investigations
Environ. Int.
The complexation of rhizosphere and nonrhizosphere soil organic matter with chromium: using elemental analysis combined with FTIR spectroscopy
Ecotoxicol. Environ. Saf.
The role of different functional groups in a novel adsorption-complexation-reduction multi-step kinetic model for hexavalent chromium retention by undissolved humic acid
Environ. Pollut.
Public health risk assessment of chromium intake from vegetable grown in the wastewater irrigated site in Bangladesh
Pollution
Chromium cycling in soils and water: links, gaps, and methods
Environ. Health Perspect.
From phytoremediation of soil contaminants to phytomanagement of ecosystem services in metal contaminated sites
Int. J. Phytoremediation
Cited by (10)
Fate and transport of chromium in industrial sites: Dynamic simulation on soil profile
2023, Science of the Total EnvironmentCitation Excerpt :Furthermore, the range of the polluted soil area would expand with the transport of metals as a function of rainfall and flow field, and thus endangering soil ecosystem functioning and threatening the wellness of human beings (Xiao et al., 2015). Cr is a common toxic soil contaminant (Liang et al., 2021) which is discharged into the soil environment in large quantities through industrial processes such as paper making, wood processing (del Real et al., 2020) and dye production (Tumolo et al., 2020). It has been estimated that 1.29 million tons of Cr are released into the environment per year, resulting in serious soil metal pollution (Coetzee et al., 2020).
Effect of biochar on the uptake, translocation and phytotoxicity of chromium in a soil-barley pot system
2022, Science of the Total EnvironmentCitation Excerpt :The Cr-contaminated soil was collected from the topsoil (0–20 cm) of the Cr slag dumps of Qingdao Hongxing Chemical Plant, Shandong Province, China. Several physicochemical properties of the tested soil, including pH (Li et al., 2021a), the content of organic matter (OM) (Pradas Del Real et al., 2020), the bulk density, and the cation exchange capacity (CEC) (Liang et al., 2006), were determined according to standard methods. The collected soil was air-dried, sieved (<2.5 mm) and remediated with different dosages (0, 5, 10, 20, 30 g·kg−1) of FBC (designated as FBC-0, FBC-5, FBC-10, FBC-20, and FBC-30, respectively).
Preparation of ternary composite (WS<inf>2</inf>-FeOCl-PANI) and its performance as auxiliary electrode in electrokinetic remediation of simulated Cr(VI) contaminated soil
2021, Journal of Environmental Chemical EngineeringCitation Excerpt :Chromium (Cr) contaminated soil produced from the chromium processing industry (e.g. leather manufacturing, printing and dyeing wastewater, etc.) has become a serious potential threat to ecological and environmental health [1–6].
Effect of the reduction–mineralization synergistic mechanism of Bacillus on the remediation of hexavalent chromium
2021, Science of the Total EnvironmentCitation Excerpt :The common forms of Cr(VI) in soil are CrO42−, Cr2O72−, and HCrO4−; these forms of Cr(VI) have weaker interactions with negatively charged colloids and can penetrate deep into the soil (Wang et al., 2020). As these forms possess a high oxidation power, they cause severe oxidative injuries and DNA damage in living organisms (Pradas et al., 2020). Cr(III) forms stable metal–organic complexes with several amines and carboxylates (Race et al., 2019).
Characterization of biochar derived from bamboo and its application to modulate the toxic effects of chromium on wheat plant
2024, Biomass Conversion and BiorefineryReduction of Hexavalent Chromium from Soil of the Relocated Factory Area with Rice Straw Hydrothermal Carbon Modified by Nano Zero-Valent Iron (nZVI)
2023, International Journal of Environmental Research and Public Health
- 1
Present address: Department of Agricultural Chemistry, Universidad Autónoma de Madrid, 28049, Madrid, Spain.