The removal of electrolytes from aqueous solutions and cyclic operation were carried out using a small size flow through capacitor apparatus. The operation condition of the apparatus which are voltage, flow rates of solution and form of carbon electrode are determind. The effect of the characteristics of activated carbons on removal of various kinds of surfates electrolytes were discussed by using 9 kinds of activated carbons which were orginated from different raw materials. It is suggested that specific surface area of activated carbons contributed siginificantly to the removal of ions. Introduction of oxygenfunctional groups on the activated carbons promotes the amount of ion removal. It was recognized that it showed a tendency of removal as much as sulfates whose ion radius was small. In the case of cyclic operation, the electrodes are discharged or short-circuited at some point, adsorbed ions are desorped and the electrode is regenerated.

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Coal tar pitch was air-blown under the various pressures and temperatures to investigate their roles on the properties of isotropic pitch fiber precursor derived from the pitch. The quality of the precursor pitches was evaluated in terms of their spinning continuity, stabilization reactivity and strength of the resultant carbon fibers. The pitches were also characterized by means of solvent fractionation and NMR spectroscopy. Lower pressure and temperature were confirmed to produce better precursor pitches for the general purpose carbon fiber of higher quality. Although the yield of the pitch was low. Efficient removal of lighter fraction without excess condensation of heavier fraction favored the quality of the pitch. The distillation before the air-blowing to remove lower boiling substances was found also effective to give better precursor pitch for the general purpose cabon fiber of higher quality. In contrast, the prehydrogenation allowed development of mesophase and decreased the 13-resin content in the air-blown pitch, being not recommended in the pretreatment.

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A newly developed SiC fiber-composite coating that was combined with SiC/SiC and CVD-SiC has been used to improve the oxidation resistance of CVD-SiC coated C/C composites at high temperatures. An SiC fiber-composite coating of about 300 gm in thickness was prepared by covering the 3D-C/C substrate with SiC felt, and by impregnating a slurry of finely dispersed C and Si powders. A CVD process was used for densification of the coating layer on the composite. In a CO₂-H₂O-N₂ containing atmosphere (CO₂9%, N₂73%, H₂O 18%), oxidation tests were applied at 1700°C for 5 h to the CVD-SiC coated C/C composites with and without the coating layer of SiC fiber-composite. The C/C composites with the SiC fiber-composite coating underwent much lower mass loss than those without the SiC fiber-composite. This SiC fiber-composite coating has a two-layer structure consisting of inner porous SiC/SiC layer and outer dense SiC layer. Since the SiC/SiC layer shows an intermediate coefficient of thermal expansion between those of C/C and CVD-SiC, this SiC/SiC layer played an important role in crack propagation of the coating to minimize the thermal stress caused by mismatching between C/C and CVD-SiC layers. The residual strengths of these samples after the oxidation test were measured with a modified small punch (MSP) test. The strengths of C/C composites measured by MSP test tend to be scattered depending on the fiber configuration of fracture part due to the presence of the fiber in the z direction. However, this method is suitable for testing a small size specimen. It was found that the residual strength after oxidation of the coated specimen developed in this study was kept high owing to its higher oxidation resistance.

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This review focuses on the structure of carbon materials with low crystallinity, especially ones prepared at relatively low temperature (500-1000°C). The category includes chars, cokes, and activated carbons, some of which are very attractive considering their future applications to the energy storage. Aside from non-carbon atoms such as hydrogen, oxygen, nitrogen, etc., these types of carbon materials are composed of small aromatic layers, partly surrounded with sp³ hybridized carbon atoms. The aromatic layers are present as a single or stacking layers, often playing important roles for formation of pores. These facts complicate the structure of such carbon materials from the viewpoint of chemical bonding, basic structure, micro-and macro-texture. Actually, experimental results for characterization of carbon materials with low crystallinity do not show distinct features in many cases. Structural information obtained by analyzing the experimental results therefore tends to be still unclear. On the other hand, some recent topics show the availability of new techniques for the quantitative structural characterization, followed by submission of model or detailed description on it. Also, combination of appropriate measurements is effective to cover the unclearness of each measurement. Here, characterization results carried out in our laboratory are shown as examples.

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An invention of the new physical battery called ECS (Energy Capacitor System) composed from specially made capacitors and electronic circuits, has opened up profound applications and possibilities. Copernican revolution indesign of energy storage capacitors is provided by trading off their internal resistance with energy density, and by charging slowly as to obtain better efficiency. Many problems inherent to capacitors such as inefficient charging, wide variation of terminal voltage and unequal distribution of voltage to each capacitors have been solved by attached electronic cir
Capacitors for the system are also specially developed. With the electronic circuits, capacitors accommodate the energy density of 10Wh/1 at 2ΩF (ohms for each farad) and 18 Wh/1 at 108ΩF. Various applications are tested ranging from solar system to home air conditioner. Power load leveler is supported by Japanese national project, a 3kWh system is built and resulted 85% AC to AC, 95% DC to DC efficiency together with record cell energy density of 27 Wh/l. A 15ton Hybrid bus powered by a 75kW ECS with a 75kW generator produced and resulted almost twice improvements of fuel mileage.

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We aim to establish a technological system which utilizes the following tow phenomena and to create the new aquatic environment industry.(1) Rapid and mass fixation of activated sludge on carbon fiber.(2) Special effects of carbon on multiplication of microorganisms.
At first, by use of carbon fiber with a water-soluble sizing agent, the various woven and knitted carbon fiber products were developed to a carrier of microbial cells and a artificial alga.
Characteristics of a mass of microbial cells fixed on the fringe of carbon fiber as compared to those fixed on other kinds of fiber are as follows.(a) The rate and amount of microbial fixations on carbon fiber are higher.(b) Fixed microorganisms are hard to be detached from the carbon fiber and their activity is higher. These characteristics of the mass of fixed microbial cells are result of the multiplier effect of the physical properties of carbon fiber and the specificity of carbon acting on the organisms.
From the results of many field examinations, these phenomena are found to be applicable in the following fields.
A) Water purification of sewage in urban areas, industrial wastewater, and pond water.
B) Forming of seaweed community in lake and sea.
C) Breeding of fireflies and pisciculture system.

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Function of carbon in treatment of polluted environmental water was studied in relation with actions of carbondependent and carbon-attaching microorganisms.

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This paper describes the basic qualitative and quantitative properties of biofilms based on extensive review ofrecent literature as well as on original research, with special view on water treatment aspects. Submerged biofilms show great complexity in structure, and in chemical and biological composition. Factors affecting biofilm properties are the microbial composition, availability (concentration) of nutrients, hydrodynamic conditions, etc. Biofilms consist of active microbial cells, extracellular material and extracellular water. Biofilm activity and mass (thickness) are determined by the surface load of key nutrients, their transport in the diffusion layer and in the biofilm, the rate of the biochemical reactions and shear-induced film losses. Biofilm models take into account the growth of one or several species of biomass, transport of several chemical components and loss of biomass due to death and shear stress. Specific surface area (mass transfer surface) of biofilms is determined primarily by the surface area and other properties of the supporting media. It is well known that carbonaceous materials have several advantages as support material, such as their chemical and mechanical stability, affinity to living organisms, high specific surface, high thermal and electric conductivity, adsorption properties, etc. High specific surface available to bacterial attachment is a key factor in controlling mass transfer problems. In this respect, carbon fibers are of great importance since they unite the easy handling of granular media and the high surface area of powders. After reviewing the most important factors governing biofilm behaviour, a simplified, model based design method is proposed for various types of polluted water and biofilm reactor configurations.

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