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Walnut shell treated with citric acid and its application as biosorbent in the removal of Zn(II)
被引:57
作者:
Judith Segovia-Sandoval, Sonia
[1
]
Ocampo-Perez, Raul
[2
]
Selene Berber-Mendoza, Maria
[1
]
Leyva-Ramos, Roberto
[2
]
Jacobo-Azuara, Araceli
[3
]
Andres Medellin-Castillo, Nahum
[1
]
机构:
[1] Univ Autonoma San Luis Potosi, Fac Ingn, Ctr Invest & Estudios Posgrad, Av Dr Manuel Nava 6, San Luis Potosi 78210, Slp, Mexico
[2] Univ Autonoma San Luis Potosi, Fac Ciencias Quim, Ctr Invest & Estudios Posgrad, Av Dr Manuel Nava 6, San Luis Potosi 78210, Slp, Mexico
[3] Univ Guanajuato, Div Ciencias Nat & Exactas, Col Noria Alta S-N, Guanajuato 36050, Gto, Mexico
关键词:
Walnut shell;
Adsorption process;
Surface diffusion;
Heavy metals;
HEAVY-METAL IONS;
AQUEOUS-SOLUTIONS;
SURFACE-DIFFUSION;
ACTIVATED CARBON;
ADSORPTION RATE;
WHEAT-STRAW;
WASTE-WATER;
ZN2+ IONS;
EQUILIBRIUM;
BIOSORPTION;
D O I:
10.1016/j.jwpe.2018.06.007
中图分类号:
X [环境科学、安全科学];
学科分类号:
08 ;
0830 ;
摘要:
In this work, walnut shell (WS) (Carya illinoinensis) treated with citric acid was used as biosorbent to remove zinc ions from aqueous solution. The effect of citric acid concentration and solution pH on the adsorption equilibrium was investigated in batch experiments. Additionally, the overall adsorption rate of Zn ions on walnut shell treated with citric acid was investigated by applying a diffusion model based on superficial diffusion. The results evidenced that a maximum adsorption capacity towards Zn(II) ions is obtained by using a citric acid concentration 2 M (WS2). The modification of walnut shell increases 2.5 times its adsorption capacity to remove Zn (II) from aqueous solutions due to the incorporation of carboxylic groups reaching a maximum adsorption capacity of 27.86 mg/g. The pH effect showed that the adsorption capacity was drastically increased by raising the solution pH from 3 to 6. The adsorption kinetics of Zn(II) on WS2 were interpreted correctly by the surface diffusional model (SDM). The values of Ds varied from 2.25 to 5.25 x 10(-9) cm(2)/s, and increased exponentially as the mass of Zn(II) adsorbed at equilibrium augmented.
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页码:45 / 53
页数:9
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