Laboratory-scale characterization of slow-release permanganate gel (SRP-G) for the in-situ treatment of chlorinated-solvent groundwater plumes.

Autor: Ogundare O; Department of Geological Sciences, University of Alabama, Tuscaloosa, AL, 35487, USA. Electronic address: ooogundare@crimson.ua.edu., Tick GR; Department of Geological Sciences, University of Alabama, Tuscaloosa, AL, 35487, USA; Santa Clara Valley Water District, Groundwater Management Unit, San Jose, CA, 95118, USA. Electronic address: gtick@ua.edu., Esfahani MR; Department of Chemical and Biological Engineering, University of Alabama, Tuscaloosa, AL, 35487, USA. Electronic address: mesfahani@eng.ua.edu., Akyol NH; Department of Geological Sciences, University of Alabama, Tuscaloosa, AL, 35487, USA; Department of Geological Engineering, Kocaeli University, 41380, Turkey. Electronic address: nakyol@ua.edu., Zhang Y; Department of Geological Sciences, University of Alabama, Tuscaloosa, AL, 35487, USA. Electronic address: yzhang264@ua.edu.
Jazyk: angličtina
Zdroj: Chemosphere [Chemosphere] 2024 Jul; Vol. 360, pp. 142392. Date of Electronic Publication: 2024 May 20.
DOI: 10.1016/j.chemosphere.2024.142392
Abstrakt: Significant challenges remain for the remediation of chlorinated-solvent plumes in groundwater, such as trichloroethene (TCE) and tetrachloroethene (PCE). A novel slow-release permanganate gel (SRP-G) technique may show promise for the in-situ treatment (remediation) of chlorinated contaminant plumes in groundwater. A series of laboratory experiments were conducted to characterize the primary physical factors that influence SRP-G gelation processes to optimize SRP-G performance for plume treatment. Specifically, experiments were conducted to quantify gel zeta potential, particle size distribution, and viscosity to determine SRP-G gelation characteristics and processes. These experiments tested various concentrations of two SRP-G amendment solutions (NaMnO 4 and KMnO 4 ) prepared with 30-wt.% and 50-wt.% colloidal silica to determine such influences on zeta potential, particle size distribution, and viscosity. The results of this study show that SRP-G solutions with low zeta potential and relatively high pH favor more rapid SRP-G gelation. The concomitant interaction of the predominantly negatively charged colloidal silica particles and the positively charged dissociated cations (Na + and K + ) in the SRP-G solution had the effect of stabilizing charge imbalance via attraction of particles and thereby inducing a greater influence on the gelation process. Gel particle size distribution and changes in viscosity had a significant influence on SRP-G solution gelation. The addition of permanganate (NaMnO 4 or KMnO 4 ) increased the average particle size distribution and the viscosity of the SRP-G solution and decreased the overall gelation time. SRP-G amendments (NaMnO 4 or KMnO 4 ) prepared with 50-wt.% colloidal silica showed more effective gelation (and reduced gelation time) compared to SRP-G amendments prepared with 30-wt.% colloidal silica. Under the conditions of these experiments, it was determined that both the 7-wt.% NaMnO 4 solution and 90 mg/L KMnO 4 solution using 50-wt.% colloidal silica would be the optimal injection SRP-G solution concentrations for this in-situ treatment technique.
Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.
(Copyright © 2024 Elsevier Ltd. All rights reserved.)
Databáze: MEDLINE
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