Preparation of carbon aerogel from waste newspaper for adsorption of antidiabetic drug residue from aqueous system

In this study, the waste newspaper was utilized to prepare carbon aerogel (CA) for adsorptive removal of Metformin hydrochloride (MH) (antidiabetic drug residues) from the aqueous system. The prepared CA was characterized using Field emission scanning electron microscopy (FE-SEM), X-ray photoelectron spectroscopy (XPS), and Brunauer-Emmett-Teller (BET) analyser. The MH adsorption was carried out using two types of water, one was laboratory-prepared distilled water and another was real river water. Although, optimum removal around 87 % was observed at pH 3, the removal efficiency at about 63 % estimated at neutral pH. In river water experiment, slightly lower rate of adsorption about 59 % was noticed. Nearly 61 % removal was found for 120 min and then no significant adsorption was found. The pseudo-second-order kinetics and Freundlich isotherm models presented a good interpretation of the adsorption experiment data. Physio-sorption was the primary mechanism of the MH adsorption was confirmed by Temkin and D-R isotherms studies. Regeneration studies demonstrated the removal stability of CA around 32 % until five cycles. An adsorption mechanism was also proposed for the removal of metformin hydrochloride using carbon aerogel.