Efficient removal of chloramphenicol by K2CO3 activated porous carbon derived from cigarette butts

Cigarette butts, composed of cellulose acetate, are non-biodegradable municipal waste. In this study, a highly porous carbon (KCBC) derived from cigarette butts via hydrothermal and K2CO3 activation was successfully prepared to turn the waste into high-value products. The as-formed porous carbon was tested for adsorptive removal of chloramphenicol (CAP) in this study. The result showed that the prepared KCBC exhibited an excellent adsorption capacity for CAP (450.13 mg/g), mainly benefiting from the high specific surface area (1421.27 m(2)/g) and rich porous structure. Adsorption isotherms, adsorption kinetics, and adsorption thermodynamics were used to study the adsorption behavior of CAP on KCBC. Results suggested that the adsorption process was a spontaneous, endothermic, entropy increase reaction. Moreover, alkaline pH and the presence of fulvic acid (FA) were not conducive to the adsorption progress, although the adsorption capacity was maintained at relatively high levels. The adsorption mechanism showed that both physical adsorption and chemical adsorption occurred during the adsorption process. Using methanol could effectively desorb CAP, and the KCBC had excellent reusability after five cycles. KCBC also exhibited outstanding adsorption effects on other antibiotics (e.g., tetracycline hydrochloride, sulfamethoxazole, metronidazole, and ciprofloxacin). This study provided a new perspective on the resource utilization of cigarette butts and the treatment of antibiotics-containing wastewater.