| Summary: | 碩士 === 國立屏東科技大學 === 森林系所 === 101 === Biochar is a solid in which biomass came out from pyrolysis under completely or partially absent of oxygen. Biochar could be a high efficacy adsorbent and applicat in pollutant treatment of heavy metals. This study had used forestry residues of Terminalia catappa L., Melia azedarach L., Swietenia macrophylla King, Liquidambar formosana Hance, Leucaena glauca (L.) Benth., Cinnamomum camphora (L.) Presl., Pisonia umbellifera (Forst.) Seem., Magnolia denudata Desr., Fraxinus formosana Hayata (Pterocarpus indicus Willd., Acacia confusa Merr. and rice husk to produce biochar and used 300 ~ 800℃ different temperature to analysis after produce biochars.
The results showed that the pH, electrical conductivity(EC), mineral elements and trace elements are increased as the pyrolysis temperature is elevated. The results of Fourier transform infrared spectroscopy (FTIR) showed that the biochar of all species contain functional group of aromatic C (C=C) Species of T. catappa, L. formosana and L. glauca. had more types of functional groups than P.umbellifera, M.denudata and A.confusa. Results of scanning electron microscopy (SEM) showed that an increase of pyrolysis temperature would increase pores on the surface of biochar. The pores on the biochar of M. azedarach, S. macrophylla, and L. glauca. at 700℃ showed the most obvious.
In the adsorption experiment of heavy mental Cu and Zn by 300, 500, and 700℃, it was found that biochar of P. umbellifera by 500℃ exhibit the best in Zn adsorption. And biochars of L. formosana and P. indicus with 500 and 700℃ also showed the highest efficiency of Cu adsorption. The rest of other tree species with 500℃ and 700℃ biochar had showed good adsorption of heavy metals, but the biochar of 500℃ was better then 700℃. In the future if biochar were used to absorb heavy metals of Cu and Zn, it may consider to use the species of P. umbellifera, L. formosana and P. indicus. for raw material. And the pyrolysis temperature in 500℃ would be commended to achieve good results for the adsorption of heavy metal.
Key words: biochar, forestry residues, heavy metals, adsorption
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