الفهرس | Only 14 pages are availabe for public view |
Abstract The application of low-cost adsorbents obtained from plant wastes as a replacement for costly conventional methods of removing heavy metal ions from wastewater has been investigated. It is well known that cellulosic waste materials can be obtained and employed as cheap adsorbents and their performance to remove heavy metal ions can be affected upon chemical treatment. In this study, cotton stalks was used as an adsorbent for the aim of removing of the Cu(H) ions from the aqueous solutions. The adsorption process was carried out in a batch process and the effects of contact time (I 5-1 80m in), liquid to solid ratio (100: I -500: I), particle size (0.2- I mm) and initial metal ion concentration (50- 300 mg! I) on the adsorption were investigated. Experimental results showed that the maximum-adsorption capacity was determined and adsorbed Cutll) ion concentration was increased with increasing adsorbent concentration and contact time. Langmuir and Freundlich models were used to describe sorption equilibrium data. Results indicated that the Langmuir model gave an acceptable fit to the experimental data than the Freundlich equation as the isothermal data of cotton stalks could be well described by the Langmuir equations with a correlation coefficient 0.976 and the Langmuir monolayer capacity had a mean value of qm =25.253 mg! g. Two simplified kinetic models including a first-order equation, pseudo-second-order are applied. Experimental results indicated that the pseudo- second order reaction model provided the best description of the data with a correlation coefficient 0.9783. FT -IR results showed that oxygen and nitrogen atoms in structure of cotton stalks were involved in Cu(II) ions adsorption. |