کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
4427159 | 1309148 | 2007 | 7 صفحه PDF | دانلود رایگان |
Application of riverbed sand for the adsorptive separation of cadmium(II) from aqueous solutions has been investigated. Removal increased from 26.8 to 56.4% by decreasing the initial concentration of cadmium from 7.5 × 10−5 to 1.0 × 10−5 M at pH 6.5, 25 °C temperature, agitation speed of 100 rpm, 100 μm particle size and 1.0 × 10−2 NaClO4 ionic strength. Process of separation is governed by first order rate kinetics. The value of rate constant of adsorption, kad, was found to be 2.30 × 10−2 per min at 25 °C. Values of coefficient of mass transfer, βL, were calculated and its value at 25 °C was found to be 1.92 × 10−2 cm/s. Values of Langmuir constant were calculated. Values of thermodynamic parameters ΔG0, ΔH0 and ΔS0 were also calculated and were recorded as −0.81 kcal/mol, −9.31 kcal/mol and −28.10 cal/mol at 25 °C. pH has been found to affect the removal of cadmium significantly and maximum removal, 58.4%, has been found at pH 8.5. Process can be used for treatment of cadmium(II) rich wastewaters.
Journal: Environmental Pollution - Volume 150, Issue 2, November 2007, Pages 251–257