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1.
J Hazard Mater ; 159(2-3): 476-82, 2008 Nov 30.
Artigo em Inglês | MEDLINE | ID: mdl-18395337

RESUMO

The aim of this research was to develop a solid regenerable catalytic adsorbent capable of removing aniline from aqueous solutions. A H-Beta zeolite was first loaded with copper in an ion-exchange process to enhance its catalytic activity. Experimental results indicated an aniline adsorption level of approximately 106-114 mg g(-1) for each of the unmodified H-Beta, the 0.5% (w/w) Cu-Beta or the 1.4 % (w/w) Cu-Beta zeolites. The adsorption processes followed the Langmuir model and the level of aniline adsorbed was largely unaffected by a change in temperature. Assessment of the aqueous stability of the exchanged copper on the Beta zeolites indicated minimum copper leaching in the range pH 5-11 thus providing a stable working pH range for both the 0.5% (w/w) and 1.4% (w/w) Cu-Beta adsorbent materials. Catalytic oxidation studies on the adsorbed aniline indicated that the presence of copper in the zeolites significantly enhanced the degradation of aniline to predominantly carbon dioxide, water and nitrogen. Five successive adsorption/catalytic oxidation cycles did not diminish the aniline adsorption capacity of the copper loaded zeolites but there was a small loss in the efficacy of the catalytic oxidation of the adsorbed aniline by the end of the 5th cycle.


Assuntos
Compostos de Anilina/análise , Eliminação de Resíduos Líquidos , Poluentes Químicos da Água/análise , Catálise , Cobre/química , Hidrocarbonetos/análise , Resinas de Troca Iônica , Oxirredução , Solubilidade , Termodinâmica , Zeolitas
2.
J Colloid Interface Sci ; 255(2): 219-24, 2002 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-12505066

RESUMO

N-methylformamide (NMF) and 1-methyl-2-pyrrolidone (NMP) were intercalated with kaolinite, characterized, and deintercalated for analysis (the NMP was intercalated after expansion of the kaolinite layers with NMF). The dynamics of guest molecules within the kaolinite lamellae was studied by means of FT-IR and liquid state (1)H and (13)C NMR on the NMF and NMP before intercalation and also on the deintercalated solutions. Both compounds were deintercalated using water. The FT-IR spectra show no significant differences before and after intercalation, for either NMF or NMP, indicating that there is no change in molecular arrangement as a result of intercalation. (1)H and (13)C NMR investigations supported the findings of the FT-IR and indicated that structural arrangement and orientation of the guest species remain the same after deintercalation. This work provides evidence that intercalation is due to weak physical bonding.

3.
Bioresour Technol ; 83(1): 27-36, 2002 May.
Artigo em Inglês | MEDLINE | ID: mdl-12058828

RESUMO

The land disposal of waste from the poultry industry and subsequent environmental implications has stimulated interest into cleaner and more useful disposal options. The review presented here details advances in the three main alternative disposal routes for poultry litter, specifically in the last decade. Results of experimental investigations into the optimisation of composting, anaerobic digestion and direct combustion are summarised. These technologies open up increased opportunities to market the energy and nutrients in poultry litter to agricultural and non-agricultural uses. Common problems experienced by the current technologies are the existence and fate of nitrogen as ammonia, pH and temperature levels, moisture content and the economics of alternative disposal methods. Further advancement of these technologies is currently receiving increased interest, both academically and commercially. However, significant financial incentives are required to attract the agricultural industry.


Assuntos
Biotecnologia/métodos , Gerenciamento de Resíduos/métodos , Matadouros , Animais , Concentração de Íons de Hidrogênio , Resíduos Industriais , Carne , Modelos Químicos , Aves Domésticas , Eliminação de Resíduos/métodos , Temperatura , Gerenciamento de Resíduos/instrumentação , Água
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