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For the development of lithium ion recovery process from seawater, a series of experimental researches were performed. Solvent extraction of lithium ion from aqueous solution using kerosene as solvent was proposed. Lithium ion is effectively extracted by thenoyltrifluoroacetone-trioctylphosphine oxide (TTA-TOPO) in kerosene within 80 min. Extraction efficiency is severely influenced by stoichiometric parameters. Among the stoichiometric parameters, volume ratio of aqueous (A) to extraction (E) solution is the most influential parameter. After extraction, lithium ion could be easily stripped from the extraction solution by acidic solutions. Stripping efficiency decreases with pH of acidic solutions, and the kind of acid does not affect the stripping efficiency. Extraction efficiency maintains at more than 93 % even when the extraction solution is recycled three times. 65 % of lithium ion can be extracted from seawater by this solvent extraction process when magnesium ion is precipitated by NH 4 OH prior to solvent extraction process. Other metallic ions in seawater decrease the extraction efficiency of lithium ion.

For the purpose of development of a chemical recycling process for carbon fiber from carbon fiber reinforced epoxy composite, a new chemical recycling system using nitric acid aqueous solution has been proposed. The recycling system is composed of hexahedral circulating flow reactor made of quartz, Teflon supporter, acid resistance pump and auxiliaries. Epoxy matrix in the composite was effectively decomposed by nitric acid aqueous solution in the circulating flow reactor and carbon fiber could be recycled without any tangle or disturbance. Optimum conditions for the recycling process have been experimentally established. Tensile strength loss of recycled carbon fiber and composition of liquid phase decomposition products were analyzed.

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The photocatalytic degradation of p-nitrophenol has been studied on TiO 2 nanoparticles prepared by hydrolysis of titanium tetraisopropoxide using ultrasonication technique coupled with sol-gel method. The titania particles prepared with ultrasonic irradiation shows the higher activity on the photocatalytic decomposition of p-nitrophenol compared to those prepared without ultrasonic irradiation.