A novel biocomposite based on peanut husk with antibacterial properties for the efficient sequestration of trimethoprim in solution: Batch and column adsorption studies

The adverse impact of emerging pollutants (such as antibiotics) on water quality and subsequently on the ecosystem makes their removal very important. Herein, peanut husk (a low-cost material) was modified with betaine via a simple synthetic route to form a novel adsorbent (PN-Bet). The efficiency of PN-Bet for the removal of trimethoprim in solution was carried out via the batch and column method. Results from the batch studies indicated that factors such as initial concentration, solution pH and temperature had an influence on the uptake of TMP onto PN-Bet. A maximum monolayer adsorption capacity of 37.6 +/- 1.5 mg g-1 (at 293 K) according to the Langmuir model was recorded with the process being exothermic in nature. Kinetic studies showed that both pseudo-first kinetic model and pseudo-second order kinetic model could describe the adsorption process indicating the complexity of the process. PN-Bet also showed some removal efficiency towards TMP in real water samples. The feasibility of PN-Bet for industrial applications was confirmed via the fixed-bed adsorption studies with the Clark model best describing the adsorption process. The facile synthetic route employed in this study involving the use of a low-cost material under benign environmental condition can help address some of the challenges associated with some reported adsorbents for the removal of TMP. Also, the development of this adsorbent with antibacterial and good reusability properties as well as high removal efficiency for TMP can serve as a model for the development of other novel adsorbents for the sequestration of both chemical and biological pollutants in wastewater.