Abstract
Wastewaters produced from the industries contain various unwanted by-products and a large number of hazardous dyes. Several treatment processes are used for the processing of effluent waters containing dyes. Adsorbent prepared from leaves of Nitraria retusa was used for removing methylene blue from wastewater. The area of the adsorbent surface, the volume of the pore, the width of the average pore and pH(ZPC) were determined as 57.8 m(2) g(-1), 0.092 cm(3) g(-1), 13.8 A and 6.2, respectively. The results of kinetic data analysis confirm a chemisorption process, and the second-order model is favorable. Adsorption isotherm constants were investigated by Langmuir, Freundlich, and Temkin models. The obtained data expressed well by the model of Langmuir. The adsorption capacities of 571.43, 763.36, and 813.01 mg g(-1) were got at 303, 323 and 333 K, correspondingly. The positive values of AH degrees and AG degrees recommend that this adsorption is an endothermic and un-spontaneous process.