Partitioning of chlorinated organic compounds from dense non-aqueous phase liquids and contaminated soils from lindane production wastes to the aqueous phase

Lorenzo, David; García-Cervilla, Raúl; Salvador, Alfredo; Santos, Aurora

doi:10.1016/j.chemosphere.2019.124798

Cited by 35 publications

(23 citation statements)

References 39 publications

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“…On the contrary, the solubilization of COCs without surfactant presents a different distribution, following the partitioning of these compounds in the aqueous phase reported elsewhere [6,39]. The distribution of COCs in the aqueous phase without surfactants is quite different from their distribution in the organic phase, where chlorobenzene is the most abundant dissolved COC.…”

Section: Int J Environ Res Public Health 2020 17 X 8 Of 15supporting

confidence: 51%

“…PentaCX, HexaCX, HCH, and HeptaCH isomers are not detected in the aqueous emulsions under alkaline conditions while TCBs and TetraCB molar percentages have remarkably increased under these conditions. It has been reported elsewhere [39] that under alkali conditions, HCH and PentaCX isomers in the aqueous phase produce TCB and HeptaCHs compounds and HexaCXs are transformed into TetraCBs. Dehydrochlorination reactions and selectivity concerning TCB and TetraCB isomers obtained are shown in Figures S8 and S9, following that reported by Lorenzo et al [39].…”

Section: Int J Environ Res Public Health 2020 17 X 8 Of 15mentioning

confidence: 91%

“…It has been reported elsewhere [39] that under alkali conditions, HCH and PentaCX isomers in the aqueous phase produce TCB and HeptaCHs compounds and HexaCXs are transformed into TetraCBs. Dehydrochlorination reactions and selectivity concerning TCB and TetraCB isomers obtained are shown in Figures S8 and S9, following that reported by Lorenzo et al [39]. Therefore, the alkaline conditions produced the transformation of some compounds in a solubilized fraction of DNAPL inside the micelles generated by the surfactant due to alkaline conditions; however, similar molar total concentration of COCs in solution is obtained at neutral and alkaline pHs.…”

Section: Int J Environ Res Public Health 2020 17 X 8 Of 15mentioning

confidence: 91%

“…The pH effect on the partitioning equilibria has been scarcely studied, although it is proved that alkaline conditions can produce dehydrochlorination reactions of pesticides as lindane [39,40] or alkaline hydrolysis of organophosphorus pesticides, such as parathion and methyl parathion [33], generating less toxic products. Muff et al [33] studied the solubilization of a NAPL compounded of two organophosphorus pesticides (50% w:w) in a polluted soil under strong alkaline conditions using several surfactants.…”

Section: Introductionmentioning

confidence: 99%

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Surfactant-Enhanced Solubilization of Chlorinated Organic Compounds Contained in DNAPL from Lindane Waste: Effect of Surfactant Type and pH

García-Cervilla

Salvador

Santos

et al. 2020

IJERPH

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Application of surfactants in the remediation of polluted sites with dense nonaqueous phase liquid (DNAPL) still requires knowledge of partitioning between surfactants and pollutants in the organic and aqueous phases and the time necessary to reach this balance. Two real DNAPLs, generated as wastes in the lindane production and taken from the polluted sites from Sabiñanigo (Spain), were used for investigating the solubilization of 28 chlorinated organic compounds (COCs) applying aqueous surfactant solutions of three nonionic surfactants (E-Mulse® 3 (E3), Tween®80 (T80), and a mixture of Tween®80-Span®80 (TS80)) and an anionic surfactant (sodium dodecyl sulfate (SDS)). The initial concentrations of surfactants were tested within the range of 3–17 g·L−1. The pH was also modified from 7 to >12. The uptake of nonionic surfactants into the organic phase was higher than the anionic surfactants. Solubilization of COCs with the nonionic surfactants showed similar molar solubilization ratios (MSR = 4.33 mmolCOCs·g−1surf), higher than SDS (MSR = 0.70 mmolCOCs·g−1SDS). Furthermore, under strong alkaline conditions, the MSR value of the nonionic surfactants was unchanged, and the MSR of SDS value increased (MSR = 1.32 mmolCOCs·g−1SDS). The nonionic surfactants did not produce preferential solubilization of COCs; meanwhile, SDS preferentially dissolved the more polar compounds in DNAPL. The time required to reach phase equilibrium was between 24 and 48 h, and this contact time should be assured to optimize the effect of the surfactant injected on COC solubilization.

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Section: Int J Environ Res Public Health 2020 17 X 8 Of 15supporting

confidence: 51%

Section: Int J Environ Res Public Health 2020 17 X 8 Of 15mentioning

confidence: 91%

Section: Int J Environ Res Public Health 2020 17 X 8 Of 15mentioning

confidence: 91%

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Surfactant-Enhanced Solubilization of Chlorinated Organic Compounds Contained in DNAPL from Lindane Waste: Effect of Surfactant Type and pH

García-Cervilla

Salvador

Santos

et al. 2020

IJERPH

Self Cite

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“…(8) and ( 9). The addition of an alkali provoked that HCH and heptachlorocyclohexane isomers adsorbed into the soil as a residual phase were converted to trichlorobenzenes and tetrachlorobenzenes, respectively, in less than 48 h. The dehydrochlorination reactions at alkaline conditions, shown in Figure 10, were previously described elsewhere [50][51][52].…”

Section: Oxidation With Activated Persulfate Fenton Reagent and Permanganatementioning

confidence: 71%

HCH-Contaminated Soils and Remediation Technologies

López¹,

Torre²,

Fernández³

2021

Soil Contamination - Threats and Sustainable Solutions

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The production of lindane (gamma isomer of hexachlorocyclohexane, γ-HCH) in the second half of the twentieth century was an inefficient process that generated vast amounts of residues of other HCH isomers, without any pesticide activity. These residues were often dumped in an uncontrolled way or unsecured landfills in points near the production sites, causing hot spots of soil and groundwater contamination on all continents. Given the persistence and hydrophobicity of these pollutants, the problem generated decades ago is still a challenge to be solved. Several technologies, based on physical, chemical, and biological treatments, have been proposed for the remediation of HCH-contaminated soils. This chapter reviews the particularities of this kind of contamination and critically examines the bases and results of the technologies applied, paying special attention to the physicochemical remediation processes.

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