Abstract
Abstract Over one-third of global terrestrial resources are contaminated by pollutants such as heavy metals, POPs, and PAHs, with more than five million soil sites exceeding regulatory heavy metal levels. This study evaluates the performance of a lab-synthesized ionic liquid, triethylammonium hydrogen sulfate ([TEA][HSO4]), in removing heavy metals from soil via phytoextraction. Response surface methodology (RSM) was applied to model the relationship between the experimental conditions and the removal efficacy of heavy metal, including Cd, Mn, Fe, Zn, Ni, Pb and As (metalloid). The operation parameters have been decided as temperature, the ratio of IL and soil and residence time. Under the optimum condition (temperature of 75 °C, IL:soil mass ratio of 30:1, and reaction time of 8 h), the [TEA][HSO4] ionic liquid synthesized in this study achieves as high removal efficiency as 98.7% for Cd, 93.9% for As, 93.0% for Mn, 61.0% for Fe, 59.5% for Zn, 51.9% for Ni and 31.8% for Pb. The novelty of this work lies not only in the high removal efficiency achieved using [TEA][HSO4], but also in its significant contribution to advancing soil remediation techniques for heavy metal contamination, minimizing negative environmental impacts on soil structure and ecosystems.