Synthesis and characterization of polyethyleneimine grafted lignocellulosic fibers for improved removal of nitazoxanide and ampicillin from water

The COVID-19 pandemic has led to increased usage of various drugs, impacting both human and environmental health. Detecting these drugs and their metabolites in water sources has become common, presenting challenges for water treatment. Adsorption processes, particularly using vegetal biomass as an adsorbent, offer an environmentally friendly solution. In this study, we chemically grafted polyethyleneimine (PEI) onto Luffa cylindrica (LF) to enhance its adsorption capacity, enabling effective removal of nitazoxanide (NTZ) and ampicillin (AMP), two drugs used in COVID-19 treatment, from water. Characterization analyses confirmed that PEI grafting induced changes in the chemical, thermal, and morphological properties of LF. The resulting grafted material (LF-g-PEI) exhibited improved adsorption capacity compared to unmodified LF for both drugs. Specifically, the adsorption capacity of LF-g-PEI increased by 59% for NTZ and 43% for AMP. Removal rates of these drugs from water using LF-g-PEI reached 59% for NTZ and 23% for AMP within 60min. The adsorption of NTZ and AMP on LF-g-PEI demonstrated higher spontaneity and a physisorption nature, primarily due to enhanced adsorbent-adsorbate interactions facilitated by PEI. LF-g-PEI showed excellent potential for reuse, enhancing its practical applicability for adsorption processes. Overall, this study illustrates that grafting PEI onto LF is a dependable strategy to boost the adsorption capacity of this vegetal biomass. The resulting adsorbent material holds promise for efficiently removing drugs commonly used in COVID-19 treatment from water sources.