Padina pavonica for the Removal of Dye from Polluted Water

Abstract

The adsorption of fast yellow dye onto dried biomass Padina pavonica was studied in batch experiments. The amount of dye adsorbed (mg/g) was increased with the increase in initial dye concentration. An equilibrium time of about 90 min was achieved for dye concentrations ranging from 5 to 160 mg/L with maximum removal percentage of 73.2%. Pseudo-first and second order kinetic models have been used to analyze the adsorption data. The pseudo second-order kinetic model adequately described the adsorption data with correlation coefficient between 0.96 and 1.084. Fourier transform infra-red analysis demonstrated the chelating character of the dye molecule to different functionalities groups of the alga. Stirring speed higher than 50 rpm revealed no significant changes in dye adsorption. Temperature ranging from 15℃ to 65℃ showed stability followed by a decrease in adsorption. Scanning electron microscopy of adsorbent particles showed a high surface porosity allowing the free passage of dye molecules.