Sawdust: Cost Effective Scavenger for the Removal of Chromium(III) Ions from Aqueous Solutions
Sawdust: Cost Effective Scavenger for the Removal of Chromium(III) Ions from Aqueous Solutions
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DOI：
10.1007/s11270-005-0217-x
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发表时间：
2005-04
期刊：
影响因子：
--
通讯作者：
R. Ahmad
中科院分区：
文献类型：
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作者：
R. Ahmad
Cr(III) ions sorption onto sawdust of spruce (Picea smithiana) has been studied thoroughly using radiotracer technique. Maximum sorption (94%) of Cr(III) ions (8.98×10−5M) onto sorbent surface is achieved from deionized water in 20 min agitation time using 200 mg of sawdust. The sorption data followed the Freundlich, Dubinin-Radushkevich (D-R) and Langmuir isotherms. Freundlich constantsl/n= 0.86 ± 0.07 andCe= 85.0 ± 25.8 mmole g−1have been estimated. Sorption capacity,Xm= 0.82± 0.3 mmole g−1, β = −0.00356± 0.00017 kJ2mole−2and energy,E= 11.9± 0.3 kJ mole−1have been evaluated using D-R isotherm. The Langmuir constantsQ= 5.8± 0.2 μmole g−1andb= (7.4± 0.5)×104dm3mole−1have been calculated. The variation of sorption with temperature yields thermodynamic parameters ΔH= −11.6± 0.3 kJ mole−1, ΔS= −16.2± 0.9 J mole−1K−1and ΔG= −6.8± 0.3 kJ mole−1at 298 K. The negative value of enthalpy and free energy reflect the exothermic and spontaneous nature of sorption respectively. Among the anions studied oxalate, citrate, carbonate and borate have reduced the sorption. The cations Y(III), Ce(II) and Ca(II) suppressed sorption. The sawdust column can be used to separate Cr(III) ion from Cs(I), I(I),Tc (VII) and Se (IV).
