Evaluation of carbon-based nanosorbents synthesised by ethylene decomposition on stainless steel substrates as potential sequestrating materials for nickel ions in aqueous solution

• Published in: Journal of environmental sciences (China) 2012-09, Vol.24 (9), p.1559-1568
• Main Authors: Lee, X.J., Lee, L.Y., Foo, L.P.Y., Tan, K.W., Hassell, D.G.
• Format: Article
• Language: English
• Subjects: adsorption; aqueous solutions; catalysts; Chemisorption; Decomposition; Ethylene; Ethylenes - chemistry; ions; iron; isotherms; kinetics; Nanocomposites; Nanomaterials; nanosorbent; Nanostructure; Nanotubes, Carbon - chemistry; Nickel; Nickel - chemistry; nickel ions; nitrogen; sorption; sorption isotherms; Stainless Steel; Stainless steels; surface area; temperature; Water - chemistry; water treatment; 不锈钢基体; 乙烯; 材料合成; 材料评价; 水溶液; 碳材料; 碳纳米材料; 镍离子
• ISSN: 1001-0742; 1878-7320
• DOI: 10.1016/S1001-0742(11)60987-X

The present work covers the preparation of carbon-based nanosorbents by ethylene decomposition on stainless steel mesh without the use of external catalyst for the treatment of water containing nickel ions （Ni2＋）. The reaction temperature was varied from 650 to 850℃, while reaction time and ethylene to nitrogen flow ratio were maintained at 30 rain and 1：1 cma/min, respectively. Results show that nanosorbents synthesised at a reaction temperature of 650℃ had the smallest average diameter （75 nm）, largest BET surface area （68.95 m2/g） and least amount of impurity （0.98 wt.% Fe）. A series of batch sorption tests were performed to evaluate the effects of initial pH, initial metal concentration and contact time on Ni2~ removal by the nanosorbents. The equilibrium data fitted well to Freundlich isotherm. The kinetic data were best correlated to a pseudo second-order model indicating that the process was of chemisorption type. Further analysis by the Boyd kinetic model revealed that boundary layer diffusion was the controlling step. This primary study suggests that the prepared material with Freundiich constants compared well with those in the literature, is a promising sorbent for the sequestration of Ni2＋ in aqueous solutions.