In the present study, electrokinetic technology was coupled with a Permeable Reactive Barrier (PRB) composed of micro-scale Fe to treat a clay soil contaminated by Perchloroethylene (PCE) as a Dense Non-Aqueous Phase Liquid (DNAPL). A nonionic surfactant, Triton X-100, was selected as the solubility enhancing agent. A series of 10 d duration batch tests were carried out in order to evaluate the fate and transport and removal of PCE and to demonstrate the effectiveness of the non-uniform EK/ZVI PRB system for the treatment of PCE-contaminated low permeability soils. A benchscale system was used, which contained 400 g of PCE contaminated soil (0.6g PCE kg-1 soil) and a PRB composed by 30 g iron particles. Seven lab-scale tests were conducted under a potential gradient of 1 V.cm-1 in order to study the influence of different variables: the effect of the surfactant, the effect of the PRB inclusion in the soil and the effect of polarity reversal. Results showed that the combination of EK and ZVI PRB could increase overall DNAPL removal from soils by 40% when compared with EK alone; the surfactant was necessary to move the pollutant trough the PRB, and the DNAPL removal generally increased by reversing the electrode polarity in the EK-PRB test (73% in Anode, 64% in Cathode). The best results showed an 80% PCE removal efficiency after 10 d.
Abstract. Environmental contaminants have been known to be present in many hazardous waste sites, which made an enormous impact on the quality of groundwater, soil and associated ecosystems. Remediation of these contaminated sites is an important challenge for the scientific and technical community. Nanotechnology is a broad and interdisciplinary field dealing with structures and particles at the nanoscale. Nano Zero Valent Iron (nZVI) is emerging as a new option for the treatment of contaminated soil and groundwater. Due to the small size, the particles are more reactive than granular iron which is conventionally applied in reactive barriers and can be used for in situ treatment. NZVI effectively reduces chlorinated organic contaminants (e.g. PCB, TCE, PCE, TCA, pesticides, solvents) and also inorganic anions (perchlorate). This present research gives an overview over the characteristics and application of nano zero valent iron in general and summarizes its use in groundwater remediation.
Abstract. This study was conducted to evaluate an integrated technique a combination of electrokinetics (EK) and zero-valent iron and a nonionic surfactant, Triton X-100(TX-100), which was selected as the solubility-enhancing agent for the remediation of soils-contaminated with Tetrachloroethylene (TCE). Four Lab-scale tests (T1 toT4) were conducted to investigate the performance of EK-PRB on TCE removal from soils. Electrical current, cumulative electro-osmosis flow and the pH in anode and cathode reservoir were measured every 24 h during the run. Results show that coupling EK with ZVI-PRB would greatly enhance the removal efficiency of TCE from soils. With this method TCE removal would generally be increased by approximately 40% when EK is coupled with PRB as compared with EK alone. The highest TCE removals were respectively recorded in T4 about 80% and 55% near to the anode and cathode of the electrokinetic cell.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.