The performance of cross-linked magnetic chitosan, coated with magnetic fluids and cross-linked with ePichlorohydrin, was investigated for the adsorption of Copper （Ⅱ） from aqueous solutions. Infrared spectra of ch...The performance of cross-linked magnetic chitosan, coated with magnetic fluids and cross-linked with ePichlorohydrin, was investigated for the adsorption of Copper （Ⅱ） from aqueous solutions. Infrared spectra of chitosan before and after modification showed that the coating and cross-linking are effective. Experiments were performed at different pH of solution and contact time, and appropriate conditions for the adsorption of Cu（Ⅱ） were determined. Experimental equilibrium data were correlated with Langmuir and Freundlich isotherms for determination of the adsorption potential. The results showed that the Langmuir isotherm was better compared with the Freundlich isotherm, and the uptake of Cu（Ⅱ） was 78.13 mg·g^- 1. The kinetics of adsorption corresponded with the first-order Langergren rate equation, and Langergren rate constants were determined.展开更多
The objective of the presented work was to assess the adsorption processes of Cu （ II ） from aqueous solution onto a granular activated carbon （GAC） and a modified activated carbon （MAC） with nitric acid. Availa...The objective of the presented work was to assess the adsorption processes of Cu （ II ） from aqueous solution onto a granular activated carbon （GAC） and a modified activated carbon （MAC） with nitric acid. Available surface functional groups, pH of the isoclectric point （pHIEP ）, and Fourier transform infrared spectroscopes were obtained to characterize the GAC/MAC. Factors influencing Cu （ II ） adsorption such as adsorbent dosage, pH of solution, and contact time of the adsorption onto the MAC/GAC had been investigated in a batch experiment. Experimental equilibrium data had been obtained and modelled using both Frenndlich and Langmuir dassicai adsorption isotherms and the data fitted better to Langmulr isotherm. It was found that nitric acid modification increased the Cu（ II ） adsorption capacity to 90.9 mg/ g, which was higher than the unmodified carbon by 41%. Two simplified models including pseudo-first-order and pseudo-second- order equations were selected to follow the adsorption processes.展开更多
文摘The performance of cross-linked magnetic chitosan, coated with magnetic fluids and cross-linked with ePichlorohydrin, was investigated for the adsorption of Copper （Ⅱ） from aqueous solutions. Infrared spectra of chitosan before and after modification showed that the coating and cross-linking are effective. Experiments were performed at different pH of solution and contact time, and appropriate conditions for the adsorption of Cu（Ⅱ） were determined. Experimental equilibrium data were correlated with Langmuir and Freundlich isotherms for determination of the adsorption potential. The results showed that the Langmuir isotherm was better compared with the Freundlich isotherm, and the uptake of Cu（Ⅱ） was 78.13 mg·g^- 1. The kinetics of adsorption corresponded with the first-order Langergren rate equation, and Langergren rate constants were determined.
基金The Key Results Promotion of Jiangxi Province,China ( No. 2009CBB00800) Key Laboratory of Radioactive Geology and Exploration Technology Fundamental Science for National Defense,China( No. 2010RGET15) Educational Committee of Jiangxi Province,China( No. GJJ12386)
文摘The objective of the presented work was to assess the adsorption processes of Cu （ II ） from aqueous solution onto a granular activated carbon （GAC） and a modified activated carbon （MAC） with nitric acid. Available surface functional groups, pH of the isoclectric point （pHIEP ）, and Fourier transform infrared spectroscopes were obtained to characterize the GAC/MAC. Factors influencing Cu （ II ） adsorption such as adsorbent dosage, pH of solution, and contact time of the adsorption onto the MAC/GAC had been investigated in a batch experiment. Experimental equilibrium data had been obtained and modelled using both Frenndlich and Langmuir dassicai adsorption isotherms and the data fitted better to Langmulr isotherm. It was found that nitric acid modification increased the Cu（ II ） adsorption capacity to 90.9 mg/ g, which was higher than the unmodified carbon by 41%. Two simplified models including pseudo-first-order and pseudo-second- order equations were selected to follow the adsorption processes.
