Recent progress on carbonaceous materials-based adsorbents derived from cigarette wastes for sustainable remediation of aquatic pollutants: A review

Cigarette butts/filters are recognized as one of the most dangerous wastes and environmental hazards worldwide due to their large quantities, non-biodegradability, and toxicity. Such wastes mainly consist of the plastic material cellulose acetate with a carbon-enriched structure, which can be a promising precursor for carbonaceous materials-based adsorbents. This review article discusses the production/modification, characterization, and utilization of carbonaceous materials-based adsorbents derived from cigarette butts/filters for aquatic pollutants removal. The most common forms of carbonaceous materials such as char, hydrochar, and activated carbon are considered. The influences of preparation/modification variables on the removal performance of such adsorbents are displayed. Moreover, the adsorption behavior under different conditions (i.e., solution pH, inlet contaminant amount, adsorbent quantity, and temperature) along with the mechanism and adsorbent reusability are also explained. The maximum uptakes of the most tested pollutants in terms of methylene blue, lead, ciprofloxacin, bisphenol A, and phenol were 635.2, 249.3, 556.2, 847.0, and 285.1 mg/g, respectively. The pseudo-second order kinetics equation and Langmuir isotherm best represented the adsorption data. Finally, the concluded notes and future suggestions are mentioned for the tested adsorbent/adsorbate systems.