Aqueous Removal of Sodium Dodecyl Benzene Sulfonate (SDBS) by Crosslinked Chitosan Films

Uncontrolled pollution of surfactants to the environment is an important problem nowadays. In this study, anionic charged surfactant sodium dodecyl benzene sulfonate (SDBS) was chosen as a model surfactant for removal studies. Biopolymer based, crosslinked chitosan films were used for the aqueous removal of SDBS. Sodium sulfate was selected as the crosslinker. Batch adsorption studies show that positively charged chitosan has an affinity towards negatively charged surfactant SDBS. Adsorption parameters such as the effect of contact time, pH, crosslinker concentration, and adsorbent dose were investigated during experimental studies. The maximum amount of adsorbed SDBS was reached at pH 2 and at 180 min. Experimental data were modeled using kinetic and isothermal models, and the system was found to be following pseudo-second order kinetics. Significantly high adsorption capacity of films (q_m) for SDBS was found as 714 mg/g. This study suggests a potential use of crosslinked chitosan films for the removal of anionic surfactants from aquatic media.