Efficiency of Magnetic CoFe2O4 Supported on Graphene for Removal of Cyanide from Wastewater
Date
2018-06-19
Authors
زبيده, أحمد خضر طه
Journal Title
Journal ISSN
Volume Title
Publisher
An-Najah National University
Abstract
There are many contaminants that seep into soil and groundwater from untreated wastewater discharched to open environment, So it causes many health problems for animals and environment, The main problem here is to detect the concentration of contaminants such as Cyanide and try to remove it by adsorption.
Produced Magnetic CoFe2O4 Graphene Oxide was characterized by several spectroscopic and analytical techniques SEM, TEM, XRD, FTIR VSM and TGA. SEM images of the magnetic showed rough and porous nature, indicating that the materials present good characteristics to be employed as an adsorbent. The adsorption experiments were conducted for a wide range of temperature, adsorbent dosage, pH, initial concentration and contact time. Result revealed that the cyanide is removed at a low temperature of 15 ° C and also in a acidic medium of 3 and the contact time after 25 and using a weight of 0.25 g of the initial dose and concentration of 15 mg / L of 50 mL CN solution. The removal efficiency of 91% of the Cyanide.
The adsorption of CN on the (M-CoFe2O4 / GO) was optimized under acidic conditions and temperatures 15 oC temperature. CN sorption using (M-CoFe2O4 / GO) can be described using pseudo second order and Langmuir isotherm model. Based on the results, the (M-CoFe2O4 / GO) is able to remove CN rapidly within 25 min with high removal efficiency.
The negative ∆G° values (-14.548to -12.595 KJ/mol) indicate that the adsorption is favorable and spontaneous at these temperatures. The negative value of ∆H° (-38.9 KJ/mol) reflects an exothermic adsorption and indicates that the adsorption is favored at temperature 15oC. The value of ∆H° was higher than those corresponding to physical adsorption. The positive value of ∆S° (+83.14 J/mol.K) suggests that some structural changes occur on the adsorbent and the randomness at the solid/liquid interface in the adsorption system increases during the adsorption process.