High levels of fluorine in soil may pose health risks and require remediation. In this study, the feasibility of using a practical chemical washing method for the removal of fluorine from an enriched soil was evaluated. The chemical washing procedures were optimized through experimental analyses of various washing solutions and washing conditions (i.e., washing solution concentration, solid–liquid ratio, agitation speed, and reaction time). Additionally, the effects of techniques for improving the washing efficiency, such as ultrasonic washing, aeration, and multi-stage washing, were evaluated. Herein, among all applied methodologies, the maximum washing efficiency achieved for the total fluorine present in soil was only 6.2%, which indicated that chemical washing was inefficient in remediating this particular soil. Further sequential extraction analysis showed that the fluorine in this soil was present in a chemically stable form (residual fraction), possibly because of the presence of mica minerals. It was demonstrated that chemical washing may not be effective for remediating soils containing such chemically stable forms of fluorine. In these cases, other physical-based remediation technologies or risk management approaches may be more suitable.

Subsurface VOC monitoring has been mainly based on manual sampling, transport, and analysis, which would require a sufficient amount of samples to ensure data accuracy and reliability, and additional costs to ensure sample quality. Therefore, a continuous on-site monitoring system is desirable for accurate measurement and subsequent risk assessment. In this study, benzene, toluene, ethylbenzene, and xylene (BTEX) were continuously monitored by the system based on a thermal desorber (TD) and gas chromatography (GC) in an oil-contaminated site that consisted of saturated and unsaturated zones. For the saturated zone, fully automated groundwater sampling and purging processes were performed, and the gasified samples were applied to the TD–GC system. For the unsaturated zone, the gaseous sample in the site was directly applied to the TD–GC system. After verifying the accuracy and precision of the monitoring system, the continuous monitoring system was successfully operated for more than a month in the field. The monitoring system used in this study is applicable to other sites for continuous monitoring, thus providing a scientific background for advanced risk assessment and policy development.

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Metals and metalloids in consumer products can be ingested by humans and cause health problems. The unified Bioaccessibility Research Group of Europe (BARGE) method (UBM, i.e., ISO 17924), with complex digestive ingredients, and the 0.07 M HCl single extraction method, as a simplified means, have been widely used to assess oral bioaccessibility in vitro. Herein, the bioaccessible concentrations of metals and metalloids in 13 certified reference materials acting as surrogates for consumer products were determined using the UBM and the 0.07 M HCl single extraction method and compared. The bioaccessible concentrations of metals and metalloids evaluated using the UBM and the 0.07 M HCl single extraction method ranged from 0.002 to 17,449 mg/kg and from 0.003 to 20,283 mg/kg, respectively; their bioaccessibility ranged from 0.00002 to 26.9% and from 0.00002 to 36.6%, respectively. The 0.07 M HCl single extraction method showed higher concentrations, as the bioaccessible concentrations of metals and metalloids differed by 1.38 times (i.e., the slope of the linear regression), indicating its potential for conservative assessment. However, the Student’s t-test results for the 12 metals and metalloids showed no significant differences (p-value ≥ 0.05). It demonstrated that the relatively simple 0.07 M HCl single extraction method can be used as an in vitro test method to assess the oral bioaccessibility of metals and metalloids in various consumer products by replacing the UBM and/or through its use as a screening method prior to the application of the UBM, thereby moving towards green analytical chemistry.