A facile synthesis of porphyrin-chitosan conjugate and its application for removing methyl orange and heavy metals from polluted water

The increasing discharge of pollutants into water bodies due to anthropogenic activities constitutes a threat to the ecosystem. To have a healthy environment, it is imperative to remove these pollutants, and adsorption is an efficient method for this purpose. However, the success of the adsorption method is predicated upon adsorbent. In this study, porphyrin-chitosan (PC) conjugate, a novel adsorbent, was synthesized and characterized by FT-IR, thermogravimetric analysis, and scanning electron microscopy. The PC conjugate and chitosan were used to adsorb methyl orange and sequestrate heavy metal ions from polluted water and the adsorption process for the methyl orange was evaluated by the established isotherm and kinetic models. The maximum adsorption capacities (qmax) determined via Langmuir model for the PC conjugate and chitosan were 352 and 57 mg/g respectively, while the adsorption process followed pseudo-second order kinetic. Consequently, the modification of chitosan with porphyrin greatly improved its performance in removing pollutants.