Journal of North Khorasan

Abstract Background & Objectives: The contamination of water by organic pollutant viz. phenolic compounds is a worldwide environmental problem due to their highly toxic nature. Biosorption has been attracted as a new technique to remove these contaminants from water and wastewater. The purpose of this study was to introduce an indigenous and inexpensive adsorbent, brown algae, for removal of phenolic compounds Material & Methods: Phenol, 2-chlorophenol and 4-chlorophenol adsorption on Cystoseira indica has been investigated using HPLC, High Performance Liquid Chromatography. Pre-treatment, protonation and chemical cross-linking with CaCl2, have been done in order to improve the stability as well as the adsorption capacity of the algal biomass. The effect of various parameters like adsorbent dose, pH, contact time and initial phenolic concentration were studied for their optimization. The equilibrium binding has been described in terms of Langmuir or Freundlich isotherms and kinetic models. Results: Data indicated that biosorption process was equilibrated for 2 hours and then desorption surpassed absorption process. Phenol showed lower elimination rate than 4-chlorophenol and 2-chlorophenol and 2-chlorophenol had most elimination. The rate of adsorption of phenol, 2-chlorophenol and 4-chlorophenol were found to be maximum at neutral pH. Equilibrium adsorption data for phenol, 2-chlorophenol and 4-chlorophenol were fitted by using Langmuir, Freundlich and Freundlich adsorption isotherms model respectively. Also it has been found that adsorption kinetics can be described according to the Pseudo-second order model, from which the R2 and the normalized standard deviation (NSD), were determined. Conclusion: The results showed reasonable adsorption capacity of Cystoseira indica brown algae and can be used as a native alternative to phenolic compounds removal from aqueous environments