Isothermal and kinetic evaluation of adsorption of organic pollutants from fish farm effluents (Aq Qala, Golestan province, Iran) by Nano composites (chitosan and activated carbon)

The purpose of present study was to study absorbent ability of organic pollutants from warm water fish farms by synthesized nano-composite adsorbent. study was performed at different physicochemical condition of pH (5-8), effluent concentration (25-100 mg/L), contact time (15-90) minutes. Adsorption isotherm studies were analyzed using Freundlich, Langmuir models and adsorption kinetics studies using pseudo-first-order and pseudo-second-order kinetic models. The Langmuir and Freundlich isotherms, first and second order adsorption kinetics were investigated. The Langmuir and Freundlich isotherms for nitrite (R2 = 0.9076, R2 = 0.5911), phosphate (R2= 0.9307, R2= 0.5755) and ammonia (R2 = 0.7288 and R2 = 0.7549), respectively obtained. According to the results, the data of nitrite and phosphate pollutants were more consistent with the Langmuir model, but the data of ammonia pollutants were more consistent with the Freundlich model. According to the results, the adsorption of phosphate pollutants was more consistent with pseudo-first order kinetic model and the adsorption of nitrite and ammonia pollutants was more consistent with the pseudo-second order kinetic model.