Biodegradation of rhamnolipid, EDTA and citric acid in cadmium and zinc contaminated soils

Wen, Jia; Stacey, Samuel P.; McLaughlin, Michael J.; Kirby, Jason K.

doi:10.1016/j.soilbio.2009.08.006

Cited by 127 publications

(42 citation statements)

References 46 publications

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“…However, concentration above 2.0% did not have any significant effect on the removal of metals. This report was in line with the finding of Wen et al (2009), who report that the degradation process would be inhibited when applied in higher doses of rhamnolipid.…”

Section: Column Washingssupporting

confidence: 92%

Biosurfactant Mediated Remediation Process Evaluation on a Mixture of Heavy Metal Spiked Topsoil Using Soil Column and Batch Washing Methods

Parthasarathi

2011

Soil and Sediment Contamination: An International Journal

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This study investigated the effects of biosurfactant produced by a mangrove isolate on a heavy metal spiked soil remediation using two different methods of biosurfactant addition (pretreatment and direct application) at different concentrations (0.5%-5%) for 10 days employing column and batch method of washings. The FT-IR spectral and biochemical analysis confirmed the chemical nature of biosurfactant as a glycolipid. Pre-addition of biosurfactant at 0.5% concentrations and further incubation for a month resulted in better chromium removal than the direct biosurfactant washing method. A maximum recovery of lead (99.77%), nickel (98.23%), copper (99.62%), and cadmium (99.71%) were achieved with column washing method at 1% biosurfactant concentration. Release of 26% soluble fractions of nickel (pre-addition with biosurfactant) and 40% copper (direct application) were achieved by column washing method at 1.0% concentration of biosurfactant. A total of 0.034 mg/10 g of lead, 0.157 mg/10 g of nickel, 0.022 mg/10 g of copper, 0.025 mg/10 g of cadmium, and 0.538 mg/10 g of chromium were found to remain in the spiked soil after column washing with 1.0% biosurfactant solution. However, pre-addition of 0.5% biosurfactant treatment helps in maximum removal of chromium metal leaving a residual concentration of 0.426 mg/10 g of soil, suggesting effective removal at very low concentration. The average extraction concentration of metals in batch washings was between 93-100%, irrespective of the concentration of biosurfactant studied. In this study, the percentage removal of copper, cadmium, chromium, nickel, and lead from spiked soils by column washing was comparatively lower than batch washing.

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Section: Column Washingssupporting

confidence: 92%

Biosurfactant Mediated Remediation Process Evaluation on a Mixture of Heavy Metal Spiked Topsoil Using Soil Column and Batch Washing Methods

Parthasarathi

2011

Soil and Sediment Contamination: An International Journal

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“…The organic acids investigated for soil treatment are acetic acid, 2) tartaric acid, 8,10) S,S-ethylenediaminedisuccinic acid (EDDS), 5) ethylenediaminetetraacetic acid (EDTA), 1,4,5,11,12) diethylenetriaminepentaacetic acid (DTPA), 12) oxalic acid 13) and citric acid. 1,4,5,8,1014) These acids have been found to be effective in removing heavy metals by forming stable chelate complexes with the heavy metals. However, some organic reagents in washing process, such as EDTA, offer disadvantages of high cost and increase in the mobility of heavy metals due to remaining reagent even after treatment.…”

Section: Introductionmentioning

confidence: 99%

“…9) Citrate is one of the predominant organic acids in soil solution 1) and there is no concern about the mobility of heavy metal ions by complexing with citric acid because it is rapidly biodegraded. 4) So there is no concern about environmental problems after the treatment. Some researchers have reported that the leaching rate with citrate is lower than that of other reagents, such as EDTA.…”

Section: Introductionmentioning

confidence: 99%

Leaching Behavior of Copper, Zinc and Lead from Contaminated Soil with Citric Acid

et al. 2013

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Soil samples contaminated with heavy metals such as lead (Pb), copper (Cu) and zinc (Zn) were leached with citric acid solution. A five step-sequential extraction method involving "exchangeable", "bound to carbonate", "bound to FeMn oxide", "bound to organic matter" and "residue" fractions was also carried out to investigate the leaching behavior of Pb, Cu and Zn with citric acid.The leaching efficiencies of Pb, Cu and Zn increased with increasing citric acid concentration. About 86.5, 88.9 and 83.3% leaching efficiencies were obtained for Cu, Zn and Pb, respectively, under the following leaching condition: 2 kmol·m ¹3 in citric acid concentration, 120 min in leaching time, 10% in pulp density, 50°C in temperature, and 80 rpm in shaking speed. In the sequential extraction test, the heavy metal contaminants were extracted more in "bound to carbonate" and "bound to FeMn oxide" fractions than in "bound to organic matter" and "residue" fractions. When the leaching efficiencies of Pb, Cu and Zn with 2 kmol·m ¹3 citric acid solution were compared with the results of the sequential extraction, a good agreement with the summation of amount leached in "exchangeable", "bound to carbonate" and "bound to FeMn oxide" fractions was noted.

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“…EDTA; Means et al 1980), creating a potential hazard of groundwater contamination through leaching , or are susceptible to rapid microbial degradation (e.g. citric acid; Römkens et al 2002;Wen et al 2009), which reduces their potential effectiveness.…”

mentioning

confidence: 99%

“…Rhamnolipid, an amphiphilic compound produced by Pseudomonas aeroginosa, is a commercially available biosurfactant and is extensively used in remediation of soil and water (Mulligan 2009). It is not recalcitrant to microbial degradation, but is persistent enough to remain in soil for periods useful for phytoextraction (Wen et al 2009). It has been widely used in soil washing to remove excess toxic metals such as cadmium (Cd), nickel (Ni) and lead (Pb; Herman et al 1995;Juwarkar et al 2007;Mulligan 2005;Wang and Mulligan 2004).…”

mentioning

confidence: 99%

Is rhamnolipid biosurfactant useful in cadmium phytoextraction?

et al. 2010

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Purpose Successful chelant-assisted phytoextraction requires application of an eco-friendly metal-complexing agent which enhances metal uptake but does not pose a significant risk of off-site movement of metals. Rhamnolipid biosurfactant has been used to enhance cadmium (Cd) removal from contaminated soil by washing. It has a strong affinity for Cd compared to some other hazardous metals, suggesting that rhamnolipid could be useful in Cd phytoextraction. This study investigated the potential use of rhamnolipid to enhance Cd phytoextraction. Materials and methods Adsorption patterns of rhamnolipid in soils were investigated by batch adsorption experiments. Hydrophobicity of rhamnolipid-metal complexes were determined by assessing partitioning in an octanol/water system. Phytotoxicity of rhamnolipid to maize (Zea mays) and chelant-assisted phytoextraction efficiency of maize and sunflower (Helianthus annuus) were determined in pot experiments. Results and discussionThe results showed that rhamnolipid was prone to adsorb strongly to soil at low application rates (0.1-1.7 mM) possibly due to its hydrophobic interactions with soil organic matter, hence reducing its capacity to complex and transport metals to plant roots. Rhamnolipid mobility increased (i.e. decreased soil phase partitioning) at elevated concentrations (∼4.4 mM), which increased soil solution Cd concentrations possibly due to its reduced hydrophobic nature. The use of rhamnolipid at concentrations >4.4 mM severely reduced maize biomass yield, reducing the potential for chelantassisted phytoextraction. At lower concentrations of rhamnolipid (0.02-1.4 mmol/kg), there was insignificant enhancement of Cd accumulation by plant (Z. mays and H. annuus) shoots, likely through strong retention of the chelant (or Cd-associated rhamnolipid) on soil surfaces. Conclusions High rates of rhamnolipid addition to soils in this study caused severe phytotoxicity to maize and sunflower. Lower rates of rhamnolpid addition to soils in this study did not improve Cd accumulation by plants. Therefore, the sorption of rhamnolipid (or Cd-associated rhamnolipid) to soils, along with the phytotoxicity and phytoextraction results, suggests that neither low nor high concentrations of rhamnolipid are likely to consistently assist Cd phytoextraction using maize or sunflower.

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Biodegradation of rhamnolipid, EDTA and citric acid in cadmium and zinc contaminated soils

Cited by 127 publications

References 46 publications

Biosurfactant Mediated Remediation Process Evaluation on a Mixture of Heavy Metal Spiked Topsoil Using Soil Column and Batch Washing Methods

Biosurfactant Mediated Remediation Process Evaluation on a Mixture of Heavy Metal Spiked Topsoil Using Soil Column and Batch Washing Methods

Leaching Behavior of Copper, Zinc and Lead from Contaminated Soil with Citric Acid

Is rhamnolipid biosurfactant useful in cadmium phytoextraction?

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