Preparation and application of phosphorylated starch as a flocculant for cationic dyes and heavy metal

Abstract

In this study, phosphorylated starch (PS) was prepared and utilized to adsorb methylene blue (MB), safranin (SF) and copper Cu (II) ions from an aqueous solution. Scanning electron microscopy (SEM) and infrared spectroscopy (IR) were used to investigate the microstructure of phosphorylated starch. The effects of adsorption period, adsorbent dose, pH, the presence of replacement groups, starting concentrations, and temperature were all studied in batch adsorption experiments. According to the findings, 10 min of adsorption time is enough to attain the adsorption equilibrium. The adsorption kinetic model can be aptly represented as the pseudo-second order (PSO). The adsorption isotherm model, is appropriately described by Freundlich and Redlich Peterson, with maximum adsorption capacity of PS was 1036 mg/g, 14994 mg/g and 1535 mg/ g for MB, Cu and SF, respectively. With fast equilibrium time (10–20 min), high adsorption efficiency (97–99%) and the regeneration and reusability of PS that can achieved, more than 3 cycles. The PS powder was a promising remediation for polluted wastewater.