Zeolitic Imidazolate/Fe3O4 Nanocomposite for Removal of Polystyrene and 4-tert-butylphenol via Adsorption

Abstract

Simultaneous removal of microplastics and endocrine disruptors was performed with high yields using Zeolitic imidazolate/Fe3O4 nanocomposite. Polystyrene and 4-tert-butylphenol were used to indicate the microplastic and endocrine disruptors. Under optimal conditions for maximum yields, the matrix was as follows: 1.5 mg/l Zeolitic imidazolate/Fe3O4 nanocomposite, 30 min adsorption time at a Zeolitic imidazolate to Fe3O4 ratio of 1/1, and 6 mg/l individual polystyrene 4-tert-butylphenol concentrations. Under these conditions, 99% and 98% removals were detected for polystyrene and 4-tert-butylphenol, respectively via adsorption. An excellent reproducibility was found for Zeolitic imidazolate/Fe3O4 nanocomposite under steadystate operational conditions. The FESEM analyses showed that Zeolitic imidazolate/Fe3O4 nanocomposite diameter was around 30 nm at a Zeolitic imidazolate to Fe3O4 nanocomposite ratio of 1/1 while some larger dodecahedral particles size was ≤ 300 nm. N2 adsorption–desorption measurements exhibited the porosity of Zeolitic imidazolate/Fe3O4 nanocomposite and the decrease of size is attributed to the incorporation of a nonporous magnetic phase via the addition of Fe2+ to the nanocomposite. BET results showed a specific surface area with a BET isotherm of 5000 m2 /g, and a pore size of 30 nm for Zeolitic imidazolate/Fe3O4 nanocomposite. In the XRD spectra of Zeolitic imidazolate/Fe3O4 nanocomposite, the structure of nanocomposite was not changed by the addition of imidazolate and Fe3O4 nanocomposite. HRTEM analysis indicated some crystal agglomerations by doping of zeolitic imidazolate to Fe3O4. The reusability of the Zeolitic imidazolate/Fe3O4 nanocomposite was excellent even after 60 times utilization. The yields were 88% and 85% after 60 runs while the nanocomposite was reused 20 times during runs with yields as high as 97% and 98%.