Vol.:(0123456789) 1 3 Environmental Science and Pollution Research https://doi.org/10.1007/s11356-022-24936-z MICROPLASTIC POLLUTANTS IN TERRESTRIAL AND AQUATIC ENVIRONMENT Indium extraction from nitrate medium using Cyphos ionic liquid 104 and its mathematical modeling Rohit Kumar 1  · Soniya Dhiman 2  · Himanshu Gupta 1 Received: 12 October 2022 / Accepted: 19 December 2022 © The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature 2022 Abstract The treatment and recovery of pollutants in aquatic system is one of the greatest challenges for environmentalists throughout the world. In this study, solvent extraction of indium using phosphonium ionic liquid (Cyphos IL 104) as an extractant and its mathematical model was proposed for prediction of In(III) ion transport across a FSSLM (fat-sheet-supported liquid membrane). Solvent extraction experiments on indium have been carried out under various experimental conditions in order to assert some fundamental parameters using mathematical analysis for mass transfer process. Difusion is the process which facilitates metal ion transport across liquid membrane, indicating the applicability of Fick’s law of difusion in model for- mulation. The infuence of diferent parameters like composition of diluent, feed acidity, and ligand concentration on In(III) ion transport rate has been reported. At diferent extractant concentrations, the modeling outputs and experimental indium extraction were observed to be in reasonably good agreement. Keywords Difusion · FSSLM · Cyphos IL 104 · Solvent extraction · Indium transport Introduction The treatment and recovery of pollutants in aquatic system is one of the greatest challenges for environmentalists through- out the world. The treatment of pollutants from water has been reported in literature using conventional techniques (Kumar and Gupta 2020; Singh et al. 2020). The impact of microplastic pollutants and other water quality drivers on lake and riverine system has also been reported (Kumar et al. 2022a, b; Barya et al. 2022). Modern technologies have showed a wide range of applications for the metal indium, which is also a precious metal and quite scarce in abun- dance. A few of the advanced technologies with high appli- cability of indium are manufacture of solar panels, fat-panel screens, and LCD lighting. The discarded waste devices are signifcant raw materials for indium, but the market demand of indium has been increased drastically (Liu et al. 2009; Fan et al. 2010). In order to comply with the market demand, the other sources of indium must be investigated. A low concen- tration of indium is available in lead, copper, and zinc ores, whereas residues or sludge of zinc melting processes may also be used to recover indium (Kai et al. 2010; Deferm et al. 2016). Therefore, it becomes necessary to develop a suitable methodology to separate indium from base metals like iron, lead, copper, and zinc. Secondary sources such as electronic or industrial wastes may also be employed to recover indium, which act as economic and eco-friendly technique with com- plete resource utilization (Silveira et al. 2015). The recovery of indium from various waste matrices has been reported in literature using diferent hydrometallurgical routes like sol- vent extraction, adsorption, precipitation, and ion exchange (Virolainen et al. 2011; Akama et al. 2016; Jiang et al. 2011; Nguyen and Lee 2019). Among them, solvent extraction is considered more advantageous due to its low energy con- sumption, rapidness, simple equipment, high selectivity, and metal recovery in highly pure form (Akama and Ito 2000; Jahroni et al. 2007). The reagents applied for solvent extrac- tion are organophosphorus compounds (Iyer and Dhadke 2001; Jha et al. 2013; Padhan and Sarangi 2014), chelating Responsible Editor: George Z. Kyzas Rohit Kumar and Soniya Dhiman have equal contribution. * Himanshu Gupta hims.research@gmail.com 1 Department of Chemistry, School of Sciences, IFTM University, Lodhipur Rajput, Uttar Pradesh 244102 Moradabad, India 2 Department of Biochemical Engineering and Biotechnology, Indian Institute of Technology Delhi, New Delhi, India