IMPROVED METHYLENE BLUE BIOSORPTION ONTO GREEN ALGAE: UlvaLactuca.

The dye removal efficiency of the green algae Ulva lactuca from textile wastewater was assessed in a batch experiment series by evaluating the initial dye concentration, contact time, pH, biosorbent quantity, and temperature. In addition, the structural characterization of Ulva lactuca for adsorption was determined using an FT-IR spectrum, SEM image, and BET analysis. After this process, methylene blue was used as a model compound for the adsorption of organic pollutants from aqueous solutions. The compatibility of isotherm models, as well as the isotherm constants and correlation values for the adsorption balance system, were determined using the experimental data. The optimum adsorption was found at around pH 7, in 10 minutes of contact time through biosorbent dose of 0.5 g/L and initial dye concentration of 5 mg/L. Within this context, biosorption value at optimum values was 0.322 mg/g. At optimum conditions, the estimated maximum removal percentage value was 89%. Langmuir, Freundlich, Temkin, and Dubinin-Radushkevich isotherm models respec-tively had determination coefficients of 0.999, 0.983, 0.988, and 0.930. The Langmuir isotherm model was rather found to be more compatible with experimental protocols. As a result of the studies for adsorption kinetics, the determination coefficient of the pseudo-second-order kinetic models was calculated as 1.000. According to thermodynamic experiments which were interpreted as an exothermic event, the adsorption event occurred non-spontaneously. [ABSTRACT FROM AUTHOR]