Effects of low-molecular-weight organic acids and residence time on desorption of Cu, Cd, and Pb from soils

Qin, Fei; Shan, Xiao-quan; Wei, Bei

doi:10.1016/j.chemosphere.2004.06.010

Cited by 209 publications

(73 citation statements)

References 45 publications

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“…The dependency of heavy metals on soil pH was consistent with the results obtained by some previous researchers (Appel and Ma 2002;Qin et al 2004). The net negative surface charge of soils increases with increasing pH, resulting in higher affinity between soil surfaces and heavy metal ions (Harter and Naidu 2001).…”

Section: Soilssupporting

confidence: 82%

“…Citric acid has the strongest ability to extract heavy metals because it has three carboxyl groups, which can form stable five-or six-member chelate rings (Qin et al 2004). However, Cu extraction from Daxin soil by citric acid with higher concentration was less than that by oxalic acid under the same conditions (Table 3), perhaps because the equilibrium pH of soil citric acid was higher than that of soil oxalic acid, as shown in Table 4.…”

Section: Resultsmentioning

confidence: 99%

“…The main form of citric acid (denoted as H 3 L) changed from H 3 L to H 2 L -to HL 2-and finally to L 3-with the increase in soil pH. Because the latter two forms had higher chelating ability to heavy metals and restricted stronger the hydrolysis of heavy metals than other formers, there was more extraction of heavy metals at higher pH (Qin et al 2004). For Chenzhou soil, the extraction of heavy metals continually decreased with increasing pH (Fig.…”

Section: Soilsmentioning

confidence: 99%

“…Low concentration of tartrate and citrate inhibited the desorption of Cd and Cu, but high concentration of tartrate and citrate promoted the desorption (Gao et al 2003). Citric acid, malic acid and acetic acid more effectively desorbed Cu, Cd and Pb from soils than inorganic salts such as CaCl 2 and NaNO 3 (Qin et al 2004). Increasing citric, oxalic or malic acid concentrations resulted in increases in Cd adsorption on acidic paddy and red soils at low pH, but citric acid dramatically increased Cd solubility at high pH (Ding et al 2008).…”

Section: Introductionmentioning

confidence: 99%

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Interaction of organic acids and pH on multi-heavy metal extraction from alkaline and acid mine soils

Ding

Song

Feng

et al. 2013

Int. J. Environ. Sci. Technol.

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Vegetation at mining sites can produce increased heavy metal leaching by the organic acids and protons originating from root secretion and litter degradation. Batch experiments were conducted to investigate the effects of organic acids and pH on the extraction of Pb, Cd, Zn and Cu from an alkaline mine soil (sampled from a mining site of Chenzhou City, Hunan Province) and an acid mine soil (sampled from a mining site of Daxin county, Guangxi Province). The results showed that in the presence of organic acids (acetic, oxalic, malic, fumaric, tartaric and citric acids) at pH 7, the extraction of Pb, Cd, Zn and Cu from the acid mine soil was much higher than that from the alkaline mine soil, in which only citric acid with higher concentration was capable of extracting some heavy metals. Citric acid had the strongest ability in extracting heavy metals, followed by oxalic acid. Heavy metal extraction dramatically decreased with increasing pH. Moreover, at low pH, oxalic acid promoted the risk of Cu leaching; at high pH, the leaching of Pb, Zn, Cd and Cu was enhanced by both oxalic and citric acids. This indicated that those plants, which can produce substantial citric acid or oxalic acid by root secretion and litter degradation, should not be selected for the revegetation of mining sites.

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Section: Soilssupporting

confidence: 82%

Section: Resultsmentioning

confidence: 99%

Section: Soilsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Interaction of organic acids and pH on multi-heavy metal extraction from alkaline and acid mine soils

Ding

Song

Feng

et al. 2013

Int. J. Environ. Sci. Technol.

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show abstract

“…S3. It was found that the adsorption of Cu/Al on peat and soil increased with an increase of solution pH, consistent to previous references (Qin et al, 2004).…”

Section: Adsorption Isothermssupporting

confidence: 91%