کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
584846 | 877899 | 2007 | 11 صفحه PDF | دانلود رایگان |
عنوان انگلیسی مقاله ISI
Sorption potential of Moringa oleifera pods for the removal of organic pollutants from aqueous solutions
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موضوعات مرتبط
مهندسی و علوم پایه
مهندسی شیمی
بهداشت و امنیت شیمی
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چکیده انگلیسی
Moringa oleifera pods Lamarck (Drumstick or Horseradish) is a multipurpose medium or small size tree from sub-Himalayan regions of north-west India and indigenous to many parts of Asia, Africa, South America, and in the Pacific and Caribbean Islands. Its pods (MOP) have been employed as an inexpensive and effective sorbent for the removal of organics, i.e., benzene, toluene, ethylbenzene and cumene (BTEC) from aqueous solutions using HPLC method. Effect of different parameters, i.e., sorbent dose 0.05-0.8 g, 25 cmâ3 agitation time 5-120 min, pH 1-10, temperature 283-308 K and concentration of sorbate (1.3-13) Ã 10â3, (1.1-11) Ã 10â3, (0.9-9) Ã 10â3, (0.8-8) Ã 10â3 mol dmâ3, on the sorption potential of MOP for BTEC have been investigated. The pore area and average pore diameter of the MOP by BET method using nitrogen as a standard are calculated to be 28.06 ± 0.8 m2 gâ1 and 86.2 ± 1.3 nm respectively. Freundlich, Langumir and Dubinin-Radushkevich (D-R) sorption isotherms were employed to evaluate the sorption capacity of MOP. Sorption capacities of BTEC onto MOP have been found to be 46 ± 10, 84 ± 9, 101 ± 4, 106 ± 32 mmol gâ1 by Freundlich, 8 ± 0.1, 9 ± 0.1, 10 ± 0.3, 9 ± 0.1 mmol gâ1 by Langumir and 15 ± 1, 21 ± 1, 23 ± 2, 22 ± 3 mmol gâ1 by D-R isotherms respectively, from BTEC solutions at 303 K. While the mean energy of sorption process 9.6 ± 0.3, 9.2 ± 0.2, 9.3 ± 0.3, 9.5 ± 0.4 kJ molâ1 for BTEC is calculated by D-R isotherm only. Rate constant of BTEC onto MOP 0.033 ± 0.003, 0.030 ± 0.002, 0.029 ± 0.002, 0.027 ± 0.002 minâ1 at solution concentration of 1.3 Ã 10â3, 1.1 Ã 10â3, 0.9 Ã 10â3 and 0.8 Ã 10â3 mol dmâ3 and at 303 K have been calculated by employing Lagergren equation. Thermodynamic parameters ÎH â8 ± 0.4, â10 ± 0.6, â11 ± 0.7, â11 ± 0.7 kJ molâ1, ÎS â22 ± 2, â26 ± 2, â27 ± 2, â29 ± 3 J molâ1 Kâ1 and ÎG303 K â0.9 ± 0.2, â1.9 ± 0.2, â2.3 ± 0.1 and â2.6 ± 0.2 kJ molâ1 were also estimated for BTEC respectively at temperatures 283-308 K. The negative values of ÎH, ÎS and ÎG suggest exothermic, stable (with no structural changes at solid-liquid interface) and spontaneous nature of sorption process under optimized conditions. MOP has been used extensively to accrue and then to preconcentrate benzene, toluene and ethylbenzene in wastewater sample.
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Journal of Hazardous Materials - Volume 141, Issue 3, 22 March 2007, Pages 546-556
Journal: Journal of Hazardous Materials - Volume 141, Issue 3, 22 March 2007, Pages 546-556
نویسندگان
Mubeena Akhtar, S. Moosa Hasany, M.I. Bhanger, Shahid Iqbal,