Exploring the Potential of Amino-Functionalized Zeolite Series/H₃PO₄-Biochar for Environmental Microplastic Removal

Abstract

The problem of microplastics (MPs) in the environment has been an emerging concern to the world in recent times. This is because the migration of MPs in the environment has been identified as deleterious culprits of the entire ecosystem and by extension may cause a decrease in life expectancy and quality of life in humans, fauna, and flora. This threat is seriously militating against the continuous existence and well-being of the entire ecosystem. Therefore, this research attempts to provide a solution to this global problem through the application of amino-functionalized zeolite series/phosphoric acid-coffee waste biochar (AFZ) for the removal of polystyrene MPs in solutions, drinking water, and wastewater. Findings from this research showed that AFZ removed 4.78 to 4.85 mg g–1 of polystyrene MPs from solutions at 20 to 50 °C, respectively. This was achieved by a combination of chemisorption and physisorption mechanisms via hydrophobic interactions between the π-electrons of the sp2 carbon orbital and π–π aromatic moieties of AFZ and the π-electrons of the polystyrene MPs and electrostatic attraction between AFZ and polystyrene MPs, respectively. Surface characterization of AFZ before and after its uptake of polystyrene MPs revealed that functional moieties such as C–H, C–O, C=C, N–H, Al–O, and Si–O was majorly responsible for the adsorption process. Hence, this research revealed that AFZ has potential to treat polystyrene MP-contaminated drinking water and wastewater.