Effectiveness of discarded cigarette butts derived carbonaceous adsorbent for heavy metals removal from water

Abstract

Disposed cigarette butt is one of the biggest solid, non-biodegradable wastes across the world. Cigarette butts (CBs) made of cellulose acetate are good candidates for the initial raw materials of carbon materials synthesis, providing a possible way for waste CBs recycling. Herein a carbonaceous adsorbent derived from waste CBs was prepared for the heavy metals removal from aqueous solution. The product activated at 500 °C has a maximum adsorption capacity for lead ions, which has a favorable balance of high specific surface area and abundant O-containing functional groups, facilitating the adsorption of heavy metals ions. The adsorption experiments showed that the pH of the solution played a pivotal role in the adsorption of heavy metals by CBs-derived activated carbons and the optimal pH for the adsorption was around 5. Effective adsorption of chromium (Cr3+), cobalt (Co2+), nickel (Ni2+), lead (Pb2+) and cadmium (Cd2+) demonstrated that the prepared materials can be used for multiple heavy metal ions removal. The prepared materials were able to adsorb Pb2+ within ten minutes, and the adsorption process can be well described by the pseudo-second order model, indicating that the chemical adsorption is the rate determining step for the adsorption process. The equilibrium data followed the Langmuir isotherm model and the corresponding maximum adsorption capacity for Pb2+ was 249.3 mg g−1. Considering the merits of low cost, easy synthesis pathway and excellent removal ability of heavy metals, CBs-derived carbonaceous adsorbent exhibits potential application in the fields of heavy metal contaminated water treatment.