Design of low-cost recyclable adsorbent based on cellulosic bags filled with carbon black derived from carrot peels for water remediation

Background: Polluted water poses a serious threat to aquatic organisms, plants, humans, and the climate. It has the potential to alter the ecosystem. Therefore, finding efficient and sustainable routes for water treatment is crucial. Methods: This study aimed to prepare carbon black from carrot peels and place it into a cellulose filter paper bag (carrot-FB) as a low-cost and reusable adsorbent. The bag was prepared from commercially available filter paper sheet with the purpose of adsorbent recyclability. Significant findings: The results showed that the adsorbent bags were selective for cadmium (Cd2+) and acridine orange (AO) removal among different metal ions and dyes, with maximum adsorption capacity of 9.69 and 2.27 mg g-1, respectively. The most effective adsorbent dosage was 10 mg, resulting in a high Cd2+ removal of 88.80% within 1 h and AO removal of 91.34% within 3 h. The adsorption isotherm and kinetic analysis revealed that the adsorbent is favorable for Cd2+ and AO removal. Moreover, the material can be recycled up to four times successively. The results revealed that the carrot-FB was effective in removing Cd2+ and AO dye from contaminated real water samples, indicating its potential application in water treatment processes.