ADSORPTION OF BASIC MAGENTA USING FRESH WATER ALGAE AND BROWN MARINE SEAWEED: CHARACTERIZATION STUDIES AND ERROR ANALYSIS

Abstract

The batch studies were performed for sorption of Basic Violet 14 onto brown seaweed (Gracilaria edulis) and fresh water algae (Lyngbya wollei) to explore potential of sorbents. The effects of pH, sorbent dosage, temperature, shaking speed, contact time and particle size on the decolorization were investigated to establish optimal conditions. The uptake rate was rapid and attains equilibrium within 90 min. The experimental isotherm data were analyzed with Langmuir, Freundlich, Dubinin-Radushkevich, Temkin equations and well explained by Temkin model. The error functions, Sum of the Squares of the Errors, Hybrid Fractional Error Function, Marquardt’s Percent Standard Deviation, Average Relative Error and Sum of Absolute Errors functions were used to determine the suitability of isotherm model with the sorption of Basic Violet 14. Both sorbents pursue Dubinin-Radushkevich isotherm model that is chemisorption, which has been confirmed with pseudo-second order and Elovich model. Fourier Transform Infrared spectra and Scanning electron microscopy images confirm the sorptivity of adsorbents. The pseudo-first-order, pseudo-second-order, initial sorption and intraparticle diffusion rate constants for different initial concentrations were deliberated for dye concentration of 20 to 100 mg/L. The diffusion rate of the dye molecules increases with increased dye concentration.

Keywords

• Basic Violet 14
• Fuchsine
• Kinetics
• Seaweed
• Error analysis