Effect of Surfactant on HCB Dechlorination by Ag/Fe Bimetal in Polluted Soil Eluent

Nie, Xiaoqin; Liu, Jianguo; Zeng, Xianwei

doi:10.1016/j.proenv.2012.10.045

Cited by 5 publications

(2 citation statements)

References 6 publications

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“…Reduction of chlorinated benzenes in presence of surfactant has been studied. Nie et al (2012) have shown that HCB dechlorination with bimetallic Ag/Fe particles (dechlorination rate of 59.5% after 20 minutes without surfactant) is clearly promoted by the nonionic surfactant TX-100, with a dechlorination rate improved to 94.1% with 20 mg L -1 TX-100, and 98.5% with 100 mg L -1 TX-100. Cationic surfactant hexadecylpyridinium bromide hydrate (HBH) has to be used at low concentrations, with an increase to 88.6% at 20 mg L -1 HBH, but the rate decreases with increasing the concentration beyond 50 mg L -1 , showing an inhibitory effect when 400 mg L -1 were added (41.3% of dechlorination).…”

Section: Surfactantmentioning

confidence: 99%

In Situ Chemical Reduction of Chlorinated Organic Compounds

Rodrigues

Betelu

Colombano

et al. 2020

Applied Environmental Science and Engineering for a Sustainable Future

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Chlorinated organic compounds (COCs) are common anthropogenic contaminants of soil and groundwater. COCs were industrially produced for different applications, such as dry cleaning, degreasing, or as pesticides. The presence of COCs in the environment is a major concern because of their toxicity and persistence.The most widely used method for their remediation is the conventional pump-and-treat system. However, this technology can hardly achieve a complete remediation because of geological characteristics and the presence of pore space pollution/adsorbed pollution, leading to a residual saturation. Hence, in addition to the improvement of pump-and-treat systems, in situ chemical processes have been largely developed. These chemical processes involve the injection of chemical reagents for the removal of residual source pollution and/or the treatment of plume contamination. Chemical degradation of COCs can be achieved by oxidative or reductive processes. If chemical oxidation has been first developed for in situ application, chemical reduction is one of the most important emerging remediation techniques for COCs treatment. Due to the electronegative character of chlorine substituents, COCs can effectively be transformed via reductive pathways. Moreover, reductive dechlorination has shown higher efficiency on highly chlorinated compounds. This chapter focuses on the presentation of the chemical reduction of the most common COCs pollutants, followed by kinetic and mechanistic approaches related to the use of iron-based particles. Developments on in situ chemical reduction technologies in order to enhance remediation rates are also exposed. Influence of environmental conditions for in situ applications is then developed. Finally, a case study is presented.

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Section: Surfactantmentioning

confidence: 99%

In Situ Chemical Reduction of Chlorinated Organic Compounds

Rodrigues

Betelu

Colombano

et al. 2020

Applied Environmental Science and Engineering for a Sustainable Future

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“…However, different factors, especially the increase in temperature, affect HLB value, resulting in higher affinity with the organic phase and the inversion of the microemulsion (progressive change from Winsor Type I to Winsor Type III and Winsor Type II). ,, Cationic surfactants are less used for subsurface applications as they tend to adsorb on negatively charged soil , and are more hazardous . Among all surfactants, nonionic surfactants Triton X-100 and Tween 80 as well as anionic surfactant SDBS are widely reported for the solubility enhancement and the enhanced remediation of chlorinated solvents. ,,− …”

Section: Introductionmentioning

confidence: 99%

Influence of Temperature and Surfactants on the Solubilization of Hexachlorobutadiene and Hexachloroethane

et al. 2017

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The solubilization of hexachlorobutadiene (HCBD) and hexachloroethane (HCA) in water as a function of temperature and in the presence of surfactants was investigated in order to predict their fate in groundwater and to increase their recovery. HCBD and HCA solubility data were experimentally determined at five temperatures in the range from (285.15 to 318.15) K. Thermodynamic parameters for dissolution (Δ sol G°, Δ sol H°, and Δ sol S°) have been calculated in order to propose a physical explanation of the minimum solubility observed between 293.15 and 298.15 K for both compounds. The solubilization process appeared to be influenced by the network of water molecules rather than by physical and chemical properties of HCBD or HCA, due to an opposite effect of temperature onto Brownian motion, which increases with temperature, and hydrogen-bond network, which collapses with temperature. Concerning the influence of surfactants, determination of the micelle−water partition coefficients (K mw) and the molar solubilization ratio (MSR) has shown that the solubilization per micelle was more important for nonionic surfactants Triton X-100 and Tween 80 than for anionic SDBS. Also, the increase of solubility was 1 order of magnitude higher for liquid HCBD than for crystalline HCA irrespective of surfactant.

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