Background: Over the last two decades, thousands of scientific papers and many patents have been written relating to applications of ionic liquids, a family of compounds that garnered such huge interest due to their reputation as "green chemicals". This work reviews the recent literature to investigate the progress ionic liquids have made in their transition from academia to full-scale application in a variety of industries. Methods: For this review, keywords related to ionic liquids and their possible applications were used to search patent databases such as Google patents. The recent patents thus discovered were tabulated and sorted by application, and the most significant patents were identified. For each application of ionic liquids identified in the patent search, an additional review of the recent scientific literature was carried out, focussing on the relevant ionic liquids and their potential environmental impact. Results: Patents involving ionic liquids were found for various industrial applications, including in chemical industry production technologies, nanotechnology, gas storage and environmental remediation. Despite the widespread interest of the chemical industry, which hopes to improve the environmental sustainability of their technologies by utilising ionic liquids, to date, only a handful of full-scale processes which utilise ionic liquids have been successfully commercialised. That said, a large number of pilot studies have been carried out in recent years, and 62 patents and 270 scientific texts are summarised herein and other industrial applications are also approaching the market. Conclusion: The properties of ionic liquids inhibit their entry into the atmosphere. However, their annual production is expected to increase drastically, raising urgent questions about their environmental impact, especially in water bodies. More research is thus required to identify and mitigate any risks ionic liquids might pose to the environment.

Global concern over arsenic contamination in drinking water necessitates innovative and sustainable remediation technologies. This study evaluates the adsorption performance of Fe–Mn binary oxide (FMBO) nanocomposites developed by coating polyethylene (PE) and polyethylene terephthalate (PET) with FMBO for the removal of As(III) and As(V) from water. Adsorption kinetics were rapid, with equilibrium achieved within 1–4 h depending on the material and pH. PET-FMBO and FMBO exhibited faster rates and higher arsenic removal (up to 96%) than PE-FMBO. Maximum As(III) adsorption capacities ranged from 4.76 to 5.75 mg/g for PE-FMBO, 7.2 to 12.0 mg/g for PET-FMBO, and up to 20.8 mg/g for FMBO, while capacities for As(V) ranged from 5.20 to 5.60 mg/g, 7.63 to 18.4 mg/g, and up to 46.2 mg/g, respectively. The results of the Dubinin–Radushkevich isotherm model, with free energy (E_a) values exceeding 16 kJ/mol, suggest chemisorption is the dominant mechanism, which is supported by the kinetics data. Given the effective removal of As(III), chemisorption likely proceeds through ligand exchange during the Mn oxide-mediated oxidation of As(III) and complexation with hydroxyl groups on the nanocomposite. These findings highlight the strong potential of Fe–Mn polymer nanocomposites, particularly PET-FMBO, for efficient arsenic removal during practical water treatment applications.

Nickel contamination in water is a critical issue due to its toxicity and persistence. This study presents a novel magnetic resin, developed by modifying Lewatit^® MonoPlus TP 207 with magnetite nanoparticles, to enhance adsorption capacity and facilitate efficient separation. A Definitive Screening Design (DSD) was employed to identify and optimize key parameters affecting nickel adsorption, including pH, resin dosage, initial nickel concentration, and the presence of competing ions (calcium and magnesium). The DSD analysis revealed that pH and magnesium concentration were the most significant factors influencing nickel removal. Optimal conditions were determined as pH 7, 270 min contact time, resin dosage of 0.5 mL/L, initial nickel concentration of 110 µg/L, calcium concentration of 275 mg/L, and magnesium concentration of 52.5 mg/L, achieving a maximum removal efficiency of 99.21%. The magnetic resin exhibited enhanced adsorption capacity and faster kinetics compared to the unmodified resin, leading to more efficient nickel removal. Moreover, its magnetic properties facilitated rapid separation from treated water, offering practical advantages for real-world applications. This study demonstrates the effective use of DSD in optimizing adsorption parameters and underscores the potential of magnetic resin as a sustainable and efficient adsorbent for water treatment.

This work explores the relationship between water quality and public trust in their water supply, in an arsenic-affected region of Serbia. The results from an online public survey are presented and subjected to Pearson’s correlation, cluster analysis, and principal component analysis. In general, survey respondents in settlements with known arsenic issues had a poor opinion on the quality of their tap water. This poor opinion was underlined by their consumption of bottled water, with more than 43% of responders purchasing at least 5 L of bottled water a week. In addition to the great economic cost, the relatively low plastic recycling rate in Serbia means that this also has a very negative effect on the environment, as most of the plastic bottles are sent to landfill, to degrade slowly into microplastics, whilst leaching a variety of chemical contaminants into the surroundings. In the area studied, the poor public opinion of the water quality is a realistic reflection of water at the tap. Although significant, the additional environmental pollution from bottled water consumption should nonetheless be of secondary consideration in comparison to the health risks associated with chemical contaminants in the study area, with local waterworks requiring significant financial assistance if they are to meaningfully improve tap water quality.

Copper contamination in aquatic environments poses significant ecological and health risks, necessitating efficient and resilient treatment strategies. In this study, graphene oxide (GO) and magnetic graphene oxide (MGO) were synthesized and comprehensively evaluated for Cu(II) removal using an integrated multivariate approach combining kinetic and isotherm modelling, Response Surface Methodology (RSM), and advanced statistical analyses. Both adsorbents achieved high removal efficiencies (>90%) under optimized conditions, with Langmuir capacities of 59.2 mg g⁻¹ for GO and 40.1 mg g⁻¹ for MGO. Kinetic modelling confirmed reaction-controlled adsorption, while Freundlich isotherms highlighted heterogeneous surface binding. RSM identified pH as the dominant factor governing removal efficiency, with significant interactions among pH, Cu(II), and DOC reflecting competitive matrix effects. Principal Component Analysis (PCA) revealed that GO performance is strongly influenced by solution chemistry, whereas MGO exhibits reduced sensitivity due to modified physicochemical properties. FTIR analysis confirmed that adsorption proceeds primarily through electrostatic attraction and inner-sphere complexation, with Fe–O sites contributing to MGO’s enhanced affinity. Regeneration studies demonstrated superior reusability of MGO, which retained ~64% efficiency after five cycles compared to ~52% for GO. Collectively, these multivariate and mechanistic insights identify MGO as a more robust, versatile, and regenerable sorbent for Cu(II) removal under realistic water-matrix conditions.