Natural guar, xanthan and carboxymethyl-cellulose-based fluids: Potential use to trap and treat hexavalent chromium in the subsurface

Siwik, Amanda; Pensini, Erica; Elsayed, Abdallah; Rodriguez, Braulio Macias; Marangoni, Alejandro G.; Collier, Christopher M.

doi:10.1016/j.jece.2018.11.051

Cited by 13 publications

(2 citation statements)

References 33 publications

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“…www.nature.com/scientificreports/ increase in their viscoelastic moduli 69,70 . Addition of ethanol (up to 5%, v/v) increased the magnitude of the viscoelastic moduli relative to pure water (Figs.…”

Section: Resultsmentioning

confidence: 99%

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Selective solvent filters for non-aqueous phase liquid separation from water

Marshall

Estepa

Corradini

et al. 2020

Sci Rep

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Injectable filters permeable to water but impermeable to non-polar solvents were developed to contain non-aqueous phase liquids (NAPL) in contaminated aquifers, hence protecting downstream receptors during NAPL remediation. Filters were produced by injecting aqueous solutions of 0.01% chitosan, hydroxyethylcellulose and quaternized hydroxyethylcellulose into sand columns, followed by rinsing with water. Polymer sorption onto silica was verified using a quartz-crystal microbalance with dissipation monitoring. Fluorescence and gas chromatography mass spectroscopy showed low ppm range concentrations of non-polar solvents (e.g., hexane and toluene) in water eluted from the filters (in the absence of emulsifiers). The contact angles between polymer-coated surfaces and hexane or toluene were > 90°, indicating surface oleophobicity. Organic, polar solvents (e.g. tetrahydrofuran and tetrachloroethylene, TCE) were not separated from water. The contact angles between polymercoated surfaces and TCE was also > 90°. However, the contact area with polymer coated surfaces was greater for TCE than non-polar solvents, suggesting higher affinity between TCE and the surfaces. Emulsifiers can be used to facilitate NAPL extraction from aquifers. Emulsion separation efficiency depended on the emulsifier used. Emulsions were not separated with classical surfactants (e.g. Tween 20 and oleic acid) or alkaline zein solutions. Partial emulsion separation was achieved with humic acids and zein particles. Petroleum hydrocarbons (e.g. toluene) are common soil and groundwater contaminants because of their historical and current use in industry 1. Oil spills in surface waters can also occur during transport by boat, threatening surface water bodies and ecosystems in their proximity 2-4. In 1969, the oil well blowout in Santa Barbara, California released 4.1-4.6 million barrels of oil 5,6. Since then, American waters have been contaminated by more than 44 oil spills (each over 420,000 US gallons) 7. Spills have also occurred in Greece (where the Agia Zoni II released over 2,500 tonnes of oil in 2017 8), in India (where the Ennore spill released 160 tonnes of oil 9) and in east China (where the Sanchi oil tanker released 136,000 tonnes of natural-gas condensate in 2018 10). In addition to sorbents 11,12 , separation sponges have been developed to clean-up oil spills in surface waters. Separation sponges can be attached onto suction ports on boats, to selectively extract oil from surface waters 13. Oil-water separation sponges are produced using different methods, including dip coating, chemical vapor deposition, in situ chemical reaction, wet chemical reaction, thermal treatment, polymerization, electroless deposition, or carbonization 13. Different materials have been used to produce sponges for oil-water separation. For instance, graphene/polyurethane sponges have been obtained by in situ polymerization of N-methylpyrrolidone in the presence of graphene 14. These sponges have been used to selectively extract hexane, crude oil and engine oil flo...

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Section: Resultsmentioning

confidence: 99%

“…2 ). In good solvents polymers acquire a stretched conformation 39 , which leads to entanglement between polymers and to an increase in their viscoelastic moduli 69 , 70 . Addition of ethanol (up to 5%, v/v) increased the magnitude of the viscoelastic moduli relative to pure water (Figs.…”

Section: Resultsmentioning

confidence: 99%

Selective solvent filters for non-aqueous phase liquid separation from water

Marshall

Estepa

Corradini

et al. 2020

Sci Rep

Self Cite

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Effect of rheology and humic acids on the transport of environmental fluids: Potential implications for soil remediation revealed through microfluidics

Siwik

Pensini

Rodriguez

et al. 2019

J of Applied Polymer Sci

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This study investigated the potential effect of shear rheology and humic acids (HA) on the subsurface transport of polymeric fluids used for the remediation of contaminants. Polymeric fluids were prepared with guar, scleroglucan, and carboxymethyl cellulose (CMC). Guar fluids can be used to suspend reactive particles for contaminant degradation. Fluids prepared with 2.5 g/L of guar in water were viscous, and the crosslinker borax (1 g/L) made them viscoelastic. Microfluidics experiments showed that the increase in elasticity blocked the flow of guar in 350 μm channels. Guar, CMC, or scleroglucan fluids containing sodium thiosulfate can be used to trap toxic Cr(VI) in the subsurface and reduce it to harmless Cr(III). Trapping of Cr(VI) is achieved by the gelation of the fluids upon contact with chromium. Before mixing with chromium, HA did not affect the flow of CMC, guar, and scleroglucan in microfluidic channels. Quartz-crystal microbalance with dissipation monitoring experiments indicates that HA reduced sorption of guar onto silica, potentially promoting the transport of guar fluids in sandy aquifers. While HA slightly decreased the rate of gelation of CMC and scleroglucan upon contact with chromium, it did not affect the fast gelation rate of guar.

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