We propose a new concrete recycling process via carbonic acid treatment. The proposed process consists of two main reactions. The first is the extraction of calcium ions (Ca²⁺) from waste cement particles in water slurry by pressurized carbon dioxide (several MPa pressure). The second is the precipitation of calcium carbonate (CaCO₃). Ca²⁺ extracted from waste cement is deposited as CaCO₃ when the pressure is reduced. In this paper, we considered to use the product, CaCO₃ as a desulfurization agent. Experimental studies were carried out in a laboratory-scale experimental apparatus to examine the feasibility of the proposed process. It was found that the extraction process can be proceed with relatively high rates in the initial 10 minutes of the reaction time, where the concentration of calcium ions exceeded thermodynamic solubility (supersaturation). The dependencies of the extraction reaction rate on the ratio of waste cement to water, CO₂ pressure, and the particle size of the raw waste cement particles were investigated experimentally with a laboratory-scale setup. Calcium carbonate with about 97 % purity was obtained in the precipitation process. A process simulation was conducted based on the experimental results, and energy consumption and the cost for a model process were estimated. The cost for the production of 1 metric-ton of CaCO₃ for desulfurization of the 500 MW thermal power pliant is estimated to be about 13000Yen.

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Hydrothermal synthesis of faujasite-type (FAU) zeolite using a coal fly ash was investigated while rotating. We discussed that the formation of FAU from coal fly ash was influenced by four synthetic factors as follows; 1) the addition of FAU seeds, 2) the addition of an aluminum source, 3) alkalinity of synthetic mixture and 4) crystallization temperature in the temperature range of 90 to 120°C. The addition of FAU seeds in the synthetic mixture was essential for the formation of FAU, otherwise GIS-type zeolite (GIS), an undesired by-product, was simultaneously formed. Higher alkaline conditions using aqueous NaOH solution (3 N) gave a higher yield of FAU (45.4 wt%). The highest yield of FAU (56.7 wt%) was obtained with the addition of 1.4 mmol (g-coal)^-1 of aluminum in 3N-aqueous NaOH solution. A further increasing amount of the addition of aluminum resulted in increasing yields of sodalite (SOD) and LTA-type zeolite (LTA). The induction period of the formation of GIS was longer at the lower crystallization temperature of 90°C.

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Zeolite synthesis from the coal ash and refuse incineration ash of circulating fluidized bed combustor (CFBC) was investigated to reuse the ashes effectively. In this study, zeolite was synthesized by hydrothermal alkali reaction. Evaluation for the possibility of zeolite synthesis from the ashes was performed by XRD analysis, SEM photograph and the capacity of ammonium ion absorption. The possibility for reuse and recycle of ashes was discussed by comparison between the coal ash and refuse incineration ash of circulating fluidized bed combustor.

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This study is aimed to promote efficiency of methane fermentation by using the sub-critical water hydrolyzed solution. To attain this, support materials, which can immobilize methanogens and adsorb substrate such as acetic acid, are very important. Four different support materials were used: bamboo charcoal, activated carbon, activated carbon with cellulose, and super absorbent polymer. The saturation capacity for adsorption of acetic acid on the activated carbon was 3.89 mol/kg. In the immobilization experiment, sludge from digester (operating at Yagi bio-ecology center) was acclimatized for 4 days with 0.1 M acetic acid and support materials. After support materials were taken out, they were washed to remove residues and then resuspended with 0.01 M acetic acid to measure methane production. Sequentially, methane production from immobilized aceticlastic methanogens on the support materials were measured. The amount of immobilized methanogens was shown by methane production from methanogens immobilized on support materials. From the experimental results, bamboo charcoal and activated carbon immobilized 40% of aceticlastic methanogens from the sludge. Activated carbon with cellulose immobilized 20%. Super absorbent polymers did not immobilize methanogens. Activated carbon with cellulose may contain utilizable organic carbon such as sugars. Thus, activated carbon with cellulose was difficult to be used as support materials for a long term. Bamboo charcoal and activated carbon may not contain such utilizable organic carbon. Therefore, bamboo charcoal and activated carbon can be used as support materials for a long term.

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Sub-critical water hydrolysis produced organic acids at 5-10 min from excess sludge. To make clear that sub-critical water hydrolysis is superior as a pretreatment, fermentation experiments were conducted in an anaerobic sewage sludge digester for three different samples: sub-critical water hydrolyzed excess sludge, model substrate in which the concentrations of the main components were close to those in sub-critical water hydrolyzed excess sludge, and acetic acid aqueous solution. In sub-critical water hydrolyzed excess sludge experiment, methane was produced drastically rapidly compared to the non-treated excess sludge. In synthetic sample experiment, about 40% of methane was produced in 5 days. Only the organic acid (mainly acetic acid) was completely consumed in 1 day. However, alanine and glycine were consumed about 60% in 5 days, and also cysteine and pyroglutamic acids were consumed to 40% in 5 days. Amino acids were not suitable for methanogen to produce biogas. When 0.01 M acetic acid was feeded into the digester, nearly 100% of acetic acid was converted to methane and carbon dioxide in 1 day. Also, approximately linear rate of methane formation (8.5 µmoles CH₄ hour^-1) was observed among 0.5, 1 and 3 hours of incubation. In this experiment the conversion efficiency of acetic acid to methane was nearly100%; 4.0, 8.5 and 32 moles of acetic acid were added to the culture, and 4.0, 8.5 and 32 µmoles CH₄ were present in headspace after incubation. The overall results suggested that high speed and high efficient methane fermentation process was obtained by using sub-critical water hydrolysis reaction as a pretreatment.

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In 2000 a large amount of waste gypsum (3.26x10⁶ tons) consisting of sulphated absorbent (2.28x10⁶ tons) and waste gypsum boards (0.98x10⁶ tons) were discarded in Japan. Most of them have been landfilled. However, there is a shortage of dump yards. Furthermore, resources need to be recovered to reduce waste loads to the environment. The present work is concerned with the regeneration of CaO by reductive decomposition of spent gypsum (CaSO₄). Reductive decomposition of CaSO₄ was carried out by using a thermogravimetric analyzer at a temperature range of 1173K to 1273K in a reductive gas mixture of CO-CO₂-H₂-N₂(CO and H₂ : 2vol%-10vol%, CO₂ : 0vol%-30vol%, N₂ : balanced). In addition, the effect of iron oxide (Fe₂O₃) additive on the enhancement of CaSO₄ decomposition was studied under CO: 2vol%, CO₂: 30vol%, N₂: balanced atmosphere at 1273K.
It was found that the regeneration of CaO from CaSO₄ was most effective when CO₂ was present in both CO-N₂ and H2-N2 atmospheres, and depended on the CO/CO2 and H₂/CO₂ concentration ratios. The CO₂ was considered to suppress the formation of an unfavorable reaction product CaS. CaSO₄ conversion of about 90% was obtained in CO, H₂: 2vol% and CO₂: 30vol% at 1273K. It was also found that the rate of reductive decomposition of CaSO₄ was accelerated by the addition of iron oxide.
It was recognized that CaO regenerated from CaSO₄ had a higher SO₂ sorption performance compared with CaO calcined from CaCO₃ due to a larger pore volume and a larger pore diameter of the regenerated CaO.

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Polyvinyl chloride (PVC) has been used extensively. On the contrary, any kinds of plastic waste recycling have been proposed. In particular, it is thought that these are reused as material for blast furnace, gasification and liquefaction. In these processes, organic chlorine such as PVC in plastic waste may causes dioxin emission or furnace corrosion. One of the processes to the solution of these problems includes prior dechlorination. There are several methods for the dechlorination treatments. However, those methods are based on the simple heat treatment by heating up the whole wastes, so other organic materials are also heating up during the dechlorination treatment. It means that the energy efficiency is very low. On the other hand, the dechlorination treatment with microwave irradiation is able to heat up the C-Cl bond selectively; and the band could be cut without deteriorating hydrocarbon. In this study, to evaluate the dechlorination behavior due to the microwave irradiation, the experiment has been done. Polyvinyl chloride (PVC) was used as organic chlorine waste. The decomposition profile of PVC in fixed bed by the microwave irradiation was compared with that by convectional heating in constant temperature in the bed. It was clarified that the rate of dechlorination by the microwave irradiation was much faster than that by the convectional heating. It also turned out that the dechlorination by the microwave irradiation started at lower temperature than that by the convection heating. Secondly, transition of dechlorination ratio and temperature in bed was measured at constant microwave output. Fluidized bed was used to irradiate evenly. It was indicated that temperature of PVC started increasing rapidly from about 450 K and dechlorination also started at any conditions. From observation of residue after irradiation, decomposition in fluidized bed took place evenly.

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Solvent extraction has been studied as a useful method to recover metals from wastewater. The conventional extraction process generally requires large quantity of organic solvent, and should be improved into the safe and environment-friendly process. In the present work, the commercial chelate extractant 5-dodecyl salicylaldoxime (LIX860-I) was immobilized in the polyvinylalcohol (PVA) gel beads and the gel beads prepared were used for recovering copper in a model wastewater containing 0.5 wt% CuSO₄·5H₂O. The gel beads of 4 to 6 mm in diameter were packed in a column of 5.4 cm in diameter and 8.2 cm in height for extracting copper from the water to the gel beads without direct contact of the solvent with the wastewater. The extraction was carried out by circulating the copper-containing water through the column at 180 ml/h. It was found that copper in the water was almost completely extracted into the gel beads, although the process required relatively long time due to the diffusion resistance of copper in gel phase. A practical extraction process was suggested to employ the initial stage of the extraction process where the rate was relatively high. The copper extracted in the gel particles was recovered by back-extraction with a high concentration of H₂SO₄ solution. The gel beads could be reused at least three times with negligible leakage of the LIX860-I and no damage to the beads. In conclusion, it was shown that the LIX860-I-entrapping PVA gel beads could be utilized repeatedly to recover copper in wastewater without using organic solvent.

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Mono- and oligo-galacturonic acids were produced from hydrothermal degradation of pectic acid in a semi-batch reactor with/without a tubular reactor installed downstream over the temperature range from 160 to 260°C at a constant pressure of 10 MPa. In the absence of the second reactor at reaction temperatures below 200°C the yields of galacturonic acid monomer were lower than 5 % on carbon basis of initial sample and the yields of total water soluble (WS) saccharides were higher than 90 %. Although the monomer yields increased at higher temperatures, the yields of total WS saccharides considerably decreased because of the further decomposition of produced saccharides. When the second reactor was installed to increase the residence time of the solution containing dissolved pectic acids, the monomer yield increased and the further decomposition of WS saccharides was suppressed: for instance, at 180°C and a residence time in the second reactor of 120 s, the yields of monomer and total WS saccharides were 22.1 and 67.0 %, respectively. The yields of monomer and the total WS saccharides were correlated with a severity parameter that combines reaction temperature and residence time. Both the increase in monomer yield and the decrease in total WS saccharide yields were proportional to the severity.

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As a key process of the biomass refinery, we have developed an atmospheric pressure superheated steam (SHS) biomass pyrolysis process that produces both carbonized materials and water solution of valuable chemicals (ca. monomeric phenols) from wood or agricultural residue. In this process, undesirable oily compound (SHS-tar) was also produced, which makes many operational problems. In this study, the production of the SHS-tar during SHS pyrolysis of Sugi (Japanese cedar, a softwood) was investigated in various temperature conditions using a small-scale batch type reactor. As a result, the tar yield was slightly increased with the pyrolysis temperature. In the case of 400°C, about 10 % of carbon contained in Sugi was converted into SHS-tar including phenol, guaiacol, methyl guaiacol, and ethyl guaiacol. Furthermore, high temperature compressed water (HCW) decomposition was performed to recover the monomeric phenols from SHS-tar. The experiment using a batch-type HCW reactor indicated that the monomeric phenols were eluted in water-phase by HCW treatment in the range of 250∼350°C under saturated vapor pressure. Furthermore, ethylguaiacol was increased as a result of HCW treatment. This production was, however, accompanied with the secondary reaction (polymerization), and the optimum condition to obtain the ethylguaiacol in this study was 350°C HCW treatment in 20 minutes including warm-up period.

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This paper describes the recovery of valuables such as organic acids and inflammable gases from biomass using a superheated steam (SHS). SHS is a thermal radiation gas which little contains oxygen and can pyrolyze (carbonize) organic materials in a short time at relatively low temperatures without burning. As an example of biomass to be treated, we dealt with wood wastes (Hinoki wood). A closed cylindrical vessel connected with a water supply pipe and an exhaust tube was used as a carbonization furnace and heated in an electric furnace. The wood samples with a cubic shape were carbonized in the superheated steam or nitrogen atmospheres under various conditions. As pyrolysis products, non-condensable gases, condensates (water and oil phases) and solid residues (i.e., charcoal) were obtained. The volume of hydrogen and methane gases contained in the non-condensable gases increased exponentially with an increase in the carbonization temperature. The concentration of organic acids such as acetic acid and lactic acid contained in the aqueous condensates increased with an increase in the carbonization temperature; however, the concentration of each organic acid was almost constant at carbonization temperatures above 673 K. From the analysis of pore characteristics of charcoals obtained in both superheated steam and nitrogen atmospheres, it has been proven that the carbonization in the superheated steam atmosphere progresses rapidly at low temperatures.

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Utilization of biomass is indispensable to qualify the future demand of energy. Biomass, however, has several disadvantages such as small calorific value, so we should develop a new technology of using effectively it. On the other hand, as for the steel manufacturing process, we must think about an effective utilization of iron sludge and scrap. In this paper, we presented a new method to produce a iron/carbon function material utilizing a carbon in biomass which can be used as a iron recycling media to blast and revolving furnaces. The method is as follows: The biomass was impregnated by iron compound aqueous solution. Through pyrolyzing the iron impregnated biomass, pure iron crystal/carbon composite was also successfully produced above 600 °C. As an option, Fe₃O₄/carbon composite was also successfully produced by the gasification with steam at low temperature. The irons in these composites were reduced by carbon with evolving CO and CO₂ at high temperature. Thus, it is clarified that the proposed method is attractive for producing alternative materials of cokes/iron ore and a recycle media of scrap using biomass.

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In this work, the conversion of heavy metals contained in fly ash into less soluble sulfides was studied. At first, fly ash was mixed with pure water, and with pure water and Na₂S solution. The ratio of Na₂S/heavy metals content in fly ash was varied from 0.15 to 1.53. Then, the suspension was shaken on vertical shaker for different time with different shaking speed. Finally, the suspension of fly ash and formed heavy metals sulfide was filtered. Both filtrate and filtration cake were analyzed. The effects of Na₂S addition, reaction time, and also shaking speed on the formation of heavy metals sulfides were investigated. The efficiency of heavy metals' sulfidation was evaluated by determination of heavy metals in filtrate after reaction with Na₂S, through the use of ICP-AES. Heavy metals were not detected in filtrate, when the ratio of Na₂S/heavy metals was higher than 0.92. The filtration cake was investigated by XRD and formation of heavy metals sulfides, especially PbS was proved. With the increasing addition of Na₂S, also reduction of the PbO peaks is possible to observe, which confirms that not only heavy metals chlorides, but also their oxides can be converted into the sulfides by the reaction with Na₂S in solution. Analyses by means of SEM-EDS also have shown similar maps for lead and sulfur. The amount of formed heavy metals sulfides in relation to shaking time was determined by TG analyzer and it was found that, after 24 hours of shaking fly ash with Na₂S (ratio 1.53), the amount of formed heavy metal sulfide is almost stable and corresponds to 34.2% heavy metals in fly ash.

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With an increase in molten fly ash emission from municipal solid waste incinerators such as gasification and melting processes, suitable treatments of the molten fly ash by separation as well as stabilization of heavy metals involved are required. In general, a large amount of heavy metals such as lead, zinc and copper are contained in molten fly ash, at concentrations much higher than those involved in natural ores. Therefore, separation technologies for effective recovery of these heavy metals from solid wastes are required to achieve material recycling system. The present paper is concerned with the separation of heavy metals from molten fly ashes by applying chloride-induced volatilization. Molten fly ash soaked with hydrochloric acid was subjected to heating experiments at 1123K in a N₂ atmosphere. Experiments were also conducted to investigate the characteristics of heavy metals volatilization with inorganic chloride compounds such as NaCl, KCl and CaCl₂ as chlorinating agents contained in the model ashes. When the molten fly ash soaked in hydrochloric acid was heated at 1123K, almost 100% of lead and zinc, and 35-60% of copper were volatilized. When heavy metal oxides; PbO, ZnO and CuO, mixed with CaCl₂, NaCl and KCl were heated at 1123K, only lead and copper were volatized. The effect of chlorinating condition on the volatilization of lead, zinc and copper in molten fly ash was also investigated.

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With the increase in molten fly ashes emitted from waste incineration such as gasification and melting process, it is important to develop effective techniques to utilize these molten fly ashes. The molten fly ashes contain high concentration of toxic heavy metals such as Pb, Zn and Cu. Currently, molten fly ashes are landfilled after immobilization treatment such as by using a chelating agent. However, due to the shortage of dump yards and exhaustion of metal resources, it is necessary to recover the heavy metals from the molten fly ash, as well as to make the molten fly ashes harmless. The present study investigates the possibility of effective recovering of heavy metals from the molten fly ashes, by volatilization of the heavy metals converted to metal chlorides by heat treatment of the molten fly ashes in a vacuum in the presence of a chlorinating agent. Experiments were carried out using model fly ashes with hydrochloric acid as a chlorinating agent to study the formation behavior of heavy metal chlorides. Experiments were also carried out using two kinds of hydrochloric acid-soaked model fly ashes to investigate the volatilization behavior of Pb, Zn and Cu at 1123K, varying the pressure in a reactor (1013hPa and 13.3hPa). It was recognized that about 100% of Pb and Zn were enhanced to vaporize within 1 minute under 13.3hPa, compared to the time for complete volatilization of Pb and Zn (60 min) under 1013hPa. It was also found that Cu was, in particular, greatly enhanced in volatilization under a reduced pressure of 13.3hPa. Almost 100% of Cu was vaporized in 120min under 13.3hPa, although only 10% of volatilization of Cu was achieved under 1013hPa.

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In the present study, a life inventory analysis was conducted on the input-output data for a livestock waste treatment plant (Yagi Bio-Ecology Center, Yagi Town, Kyoto), where bio-gas is recovered from the organic waste slurry of livestock's feces and urine collected from livestock farms, and bean curd refuse from food industries through an anaerobic digestion tank and then converted into electricity with a gas-engine generator. The livestock waste treatment plant successfully achieves zero-emission because the dehydrated secondary sludge from an anaerobic digestion tank is mixed with fresh livestock wastes and converted into compost. The whole process was analyzed on the basis of a life cycle inventory model using the cumulative CO₂ emission unit as an index in order to evaluate the environmental impact over the long term operation for the waste treatment process. In evaluating the environmental impact of the whole system, the initial construction of the facilities, the utility inputs such as water, electricity and fuel oils for maintaining the process facilities are also taken into consideration. It is ascertained that the livestock wastes treatment plant can definitely work as an efficient CO₂ sink, while generating excess electricity at a CO₂ emission unit of 0.703 kg-CO₂/kWh for a long term operation and achieving zero-emission without excreting any secondary wastes. It is also indicated that the use of a fuel cell generator in place of the gas engine generator would significantly increase the amount of electricity generated and the reduced CO₂ amount increases by a factor of 2.16 in comparison with that for the present gas engine generation system.

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In recent years, the formation of a recycling society has been promoted in Japan, and many studies have been conducted in an attempt to recycle resources and circulate them. However, energy loss always accompanies a material cycle because the materials used as products deteriorate, become mixed and diffuse, so in order to circulate such materials it becomes necessary to collect them, to separate them, and to extract poisonous substances from them, etc. This study will show, based on the material flow in Japan, that energy loss occurred at each stage of the material cycle, from resources to raw materials, from raw materials to products, from products to wastes and particularly from wastes to recycled resources. And this study will also show that the amount of materials that could be recycled is about 10 % (about 200 million tons) of the entire amount of materials used in Japan (about 2 billion tons), and to recycle such amount of materials could be accompanied by a great deal of energy loss from the viewpoint of the increase of entropy and Separative Work Unit (SWU). o, whereas that in the effluent from the production reactor was maintained at high value. This system permitted to continuously produce the cyst cells with high astaxanthin content.

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In order to perform large scale afforestation of arid land aiming at fixation of the atmospheric carbon dioxide, it is necessary to clarify the water balance and the level of salt accumulation in arid land. In this study, the residence time of the water (water age) on surface soil was related to the salt concentration of the soil. The model which can show the salt distribution and water balance in a large area was developed by using the relation of water age and salt concentration. The optimal afforestation area was estimated by the model. Moreover, effect of the measure to prevent a runoff on the water balance was estimated. This model was verified by the data measured in an experimental arid land in Western Australia. Furthermore, the creek water played an important role for the afforestation.

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There are some hazardous substances in useful industrial materials that are poisonous to human health, environment, or other materials. Such substances can be generated in any stage of social material circulation such as production, product use, and waste treatment. Therefore, we must introduce a process that eliminates such hazardous materials from the social material circulation system. We have studied the effects of the factors of the recycling ratio (r) and removal ratio (s) on the accumulated amount of hazardous materials (Q), in particular on six heavy metals: Cd, Pb, Cr (VI), As, Hg and Se, where Q is described as the summation of the Hg t-toxic equivalent quantity of the six heavy metals. In a complete recycling society (where r = 1.0), the Q becomes 5,000 times more than the allowance level in spite of a high removal effort (s = 0.9). Even under the condition of a rather low recycling level (r = 0.4), we must remove more than 99.99 % of the hazardous materials to satisfy the allowance level of the environmental standard of Hg. Consequently, we have pointed out some problems in establishing a recycle-based society from the viewpoint of the elimination of poisons. As a case study, we discussed if an ultimate elimination could be theoretically achieved in a high performance elimination process in which the temperature, the partial pressures of O₂ and Cl₂ are controlled.

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Selective oxidation of hydrogen sulfide was studied on zeolite-NaX and zeolite-KX. Elemental sulfur yield on zeolite-NaX was achieved about 90% at 225°C for the first 4 hours, but it was gradually decreased to 55% at 40 hours after the reaction started. However, the yield on zeolite-KX was obtained in the range of 87∼85% at the same reaction condition after 40 hours. The deactivation of the zeolite-NaX catalyst was caused by the coverage of the certain sulfureous species. The coverage of the sulfureous species on the zeolite-NaX was confirmed by the temperature-programmed oxidation experiments utilizing thermogravimetric analyses. Even though the higher temperature conditions for the selective oxidation were required for preventing the deactivation, it can not be raised into 250°C or above due to the SO₂ production. The SO₂ production was observed in the selective oxidation on zeolite-NaX rather than on zeolite-KX and was affected on the decrease of selectivity to the elemental sulfur. Result in this study showed that the zeolite-KX is superior to the zeolite-NaX for the selective oxidation of hydrogen sulfide to the elemental sulfur.

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The present states of the municipal solid wastes (MSW) in developing areas were studied in the first place. The amount of the wastes increased remarkably with economic and population growths. The wastes contained large amount of food waste and, thus, that of moisture. Almost all amounts of the wastes were landfilled directly without any pre-treatment. These situations of the municipal solid wastes resulted in the latest serious shortage of the landfill site and environmental problems around the site. Usable form of energy was hardly recovered from the wastes. Secondly, we selected respective waste treatment methods applicable to the MSW management in the developing areas and compared them. Since the selected methods had both merits and demerits, it was pointed out that these methods should be used together to make up for their demerits with one another. According to these studies of the municipal solid wastes and treatment methods, the MSW management process consisting of methane fermentation, composting, and incineration followed by the landfill was synthesized for the developing areas. The process was simulated with the various kinds of parameters related to the properties of municipal solid waste in the developing areas, the treatment methods, and so forth. The simulation showed that the rates of the wastes and the moistures landfilled and accumulated in the site decrease considerably and the energy can be recovered especially from the methane fermentation and incineration as a sufficient electrical power to operate the whole process. Consequently, this was proposed as a novel MSW management process in the developing areas.

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The establishment of the technology for a large scale afforestation of arid land for carbon fixation on land is required. The effective water use is very important for afforestation of arid land, because arid land has the problem of water shortage for plant growth. The object of this study is the establishment of a method to estimate water/carbon ratio (R_W/C) of tree in an arid land. In the present study, we measured to the nutrients in a tree tissue and sap for estimating R_W/C more accurately. Nutrients go into a tree with water from soil, and are fixed in the tree with carbon. Six tree species were used for our experiment. The distribution of nutrients in each part of a tree were measured. Furthermore, dry weight and nutrient content in each part (leaf, branch and trunk) of a tree were measured. Using the above data, the water quantity required to fix unit carbon for a tree (R_W/C) was calculated for potassium which was uniformly distributed, while calcium contents in each part and sap of the tree were found to be different at different levels (height). A modified model to calculate the R_W/C was constructed by the consideration of calcium distribution to get about 40-300kg-water/kg-carbon, which was almost same as that for potassium as tracer. Finally, the R_W/C based on calcium content agreed well with the ratio calculated from measured photosynthetic and transpiration rates. It was also measured that these values (R_W/C) were large for Eucalyptus, small for Acacia and middle for Casuarina. These can explain a natural growth of these trees in an experimental arid land in Western Australia.

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Aggregate structure is said to be the ideal soil structure for plant growth, because it has high water permeability together with high water retention capacity. When considering arid land afforestation, the high water permeability and high water retention capacity are essential to utilize the limited amount of water for plant growth. In the present study, artificial aggregate formation was performed in order to improve the water permeability and water retention capacity. Some kinds of soil conditioners, minced worm, humic acid, gypsum and leaves of Eucalyptus camaldulensis (E.C.) thought to be effective to form aggregates, were mixed with wet black soil. The mixed effect of soil conditioners was quantitatively estimated by the aggregate fraction, the water retention capacity and water permeability. After mixing a soil conditioner, increase in the aggregate fraction was found in the order of humic acid < gypsum < minced worm < leaves of E.C. This effect was continued for 20 months. And the water permeability of each soil sample was high in the same older. The water retention capacity was estimated in pF (log|-cmH₂O|) range between 1.8-4.2, where the soil water is available to plant growth. The soil mixed with humic acid and gypsum was increase in both of the water permeability and water retention capacity. The effect of aggregate formation on these physical properties of soil was discussed.

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Iron may play a key role in the growth of cyanobacteria, which sometimes cause to form water blooms in eutrophic water environment. To evaluate the influence of iron depletion on the growth of Anabaena circinalis, a bloom-forming cyanobacterium, ex-situ cultivation experiments using defined chemical components was conducted. It was found that (a) contrast to normal cultivation (iron concentration is at 10^-6M), growth of A.circinalis was strongly suppressed by iron depletion lower than the order of 10^-9M, especially assessed in terms of chlorophyll-a than cell concentration, (b) supplying iron to the growth-suppressed A.circinalis restored its growth almost to normal.

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The use of pentachlorophenol (PCP) as a wood-preserving agent at many wood treating sites has resulted in widespread contamination of the environment. Biodegradation catalyzed by oxidative enzymes such as horseradish peroxidase (HRP) has been proposed as a treatment method for aqueous PCP. One major issue associated with the use of enzymes is enzyme inactivation which increases treatment costs due to the high cost of the enzymes. To enhance the cost-effectiveness of the enzymatic approach, various additives have been tested for their ability to minimize enzyme inactivation. This study was initiated to investigate the potential influence of two nonionic surfactants (Tween 20 and Tween 80) on the catalytic behavior of HRP in PCP transformation. The surfactants were tested at concentrations below and above their critical micelle concentrations (CMC). Enhancement of PCP removal was observed at sub-CMC concentrations. The presence of surfactant in the reaction mixture reduced enzyme inactivation which occurred predominantly through binding with pentachlorophenoxyl radicals. At supra-CMC concentrations, the surfactants caused a noticeable reduction in PCP removal from the reaction mixture, presumably through micelle partitioning of the hydrophobic PCP molecules, precluding them from interacting with the enzyme.

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Coriolus hirsutus IFO 4917 has the ability to degrade various xenobiotics. This study was concerned with kinetics of soil-bioremediation with this fungus. Bisphenol A (BPA; 2,2-bis (4-hydroxyphenyl) propane), which is a hormone-disrupting chemical but used widely as a raw material for polycarbonates, epoxy resins, phenol resins and polyesters, was used as a model xenobiotics. The soil contaminated with BPA was treated by C. hirsutus at different conditions. The fungus was pre-cultured using MYG medium (malt extract: 10 g/L, yeastextract: 4.0 g/L and glucose: 4.0 g/L) for 3d on a shaker at 298K. Contaminated soil was prepared by adding a fixed amount of BPA-ethanol solution into a fixed amount of commercial soil that were sterilized by autoclave five times. Soil moisture content was adjusted with distilled water. The bioremediation was performed in a 300mL Erlenmeyer flask (reactor A) and a 40mL fixed-bed (reactor B). Reactor B was cylindrical type had a fused-in fritted glass disc (pore size: 100-160 µm) at the bottom. At the beginning of incubation, pre-cultured fungus was inoculated into the prepared soil in the reactor. During incubation, the moisture was kept constant by daily addition of distilled water. BPA in treated soils was extracted and analyzed using HPLC. In reactor A at 40%-moisture about 92% of initial BPA was degraded for 35d. Experimental parameters were changed and their effects on the degradation were studied. The increase in the soil moisture had a positive effect on the biodegradation. In the experiment with reactor B, the aeration stimulated the biodegradation.

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A series experiments for the removal of heavy metals from soils has been carried out by the electro-kinetic remediation, utilizing the electro-osmosis and the ionic migration phenomena under the electric field. The effect of the operational conditions on the removal efficiency was investigated using a bench scale test cell and it is concluded that the pH control of the catholyte was the important factor to improve the removal efficiency. Next, the attempt to remove heavy metals from the sediment of a lake was done and it was found that some heavy metals were successfully removed, but the other were not, because complicated precipitation reactions occurred in the sediment. A simulation model is indispensable to evaluate a remediation technology, because the remediation of contaminated soils requires a long time processing. An advection-dispersion one-dimensional model in the porous medium with chemical reactions such as precipitation and dissolution was proposed. Equations in the model were solved by Excel spread sheet, and the result was compared with experimental data. The precipitation by the model was qualitatively agreed with the behavior of ionic species in the soil

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The micro bubbles entraining method using alkaline water has been applied to the remediation of oil-contaminated sand and soil. Although this method can effectively remove not only light but also heavy oils such as asphaltene, the resultant soil sometimes needs further treatment to meet environmental standards. Biodegradation can be used as one means of removing the remaining oils. Therefore, the aim of this research was to collect microorganisms capable of degrading oils remaining in alkaline-washed soil, and to investigate the effects of such microorganisms on oil removal from alkaline-washed soil.
Sixty soil samples were acclimatized in the wastewater from the washing process. We obtained seven microorganisms capable of degrading oils out of the sixty selected. One of them removed 90% of the oil in the alkaline-washed soil in 60 days. A mass balance of about 100% was achieved for the degradation of oil in the alkaline-washed soil. Continuous addition of the collected microorganism and a continuous supply of air accelerated the microbial oil degradation in the alkaline-washed soil.

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PCBs leaked to the environments have been stored in aquatic bottom sediments for a long time. Since PCBs are highly bioaccumulative and disrupt endocrine systems in animals and humans, PCBs-contaminated bottom sediments must be treated for aquatic environment management. Several technologies have been invented for such treatment, whereas these require sediment dredging followed by dehydration of sediments, resulting in the occurrence of wastewater containing PCBs. In the present study, an ozone treatment that requires no dewatering process was tested. KC-300 was used as model PCBs to confirm the feasibility of remediating PCBs-contaminated sediments. 5 g of KC-300 contaminated soil and 95 ml of water were added to the reactor, and then ozone was injected into the bottom for 2 hours. In the control experiment, ozone was substituted by air. The PCBs removal rate by the ozone treatment was determined to be 42 %, while adding 0.5 ml of 30 % hydrogen peroxide as pro-oxidant considerably increased the removal rate of up to 73 %. When the H₂O₂ reagent was added 4 times, a removal rate of 91 % was attained. Even though the amounts of the contaminated soil treated in this O₃/H₂O₂ system increased four times, removal rates over 90% were achieved by 2 h of ozonation. The degradation of PCBs in the O₃/H₂O₂ treatment obeyed pseudo-second order kinetics. These results confirmed the feasibility of remediating PCBs-contaminated sediments by a O₃/H₂O₂ treatment.

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In urban areas, heavy rains of only a few hours' duration can cause flood, whereas people living there are likely to be faced with water shortage crisis when rains are few. Further, organic, nitric and phosphate pollution of the river is a problem in these areas. This largely depends on the land use on the basin. In the present study, a water recycling model using Geographic Information Systems (GIS) including land use data was constructed to estimate the run-off system and the water pollution on the basin. This GIS model was applied to assess the present and future water environment in Hachioji City, Tokyo, Japan, focusing on Asakawa River and its branches.
The basin area was determined automatically by calculation of the land slant, and then the outflow consisting of three kinds of flows, i.e. surface flow upon raining, intermediate ground-permeated flow and the last base flow, was estimated. The evapotranspiration parameter was set up for every land use, and water pollution load calculation was made by unit method. Finally, the basin area was determined with sufficient accuracy as compared to the actual data with 4 % error, and the study was extended to predict the water quality (BOD, SS, T-N, T-P) and river flow as applicable when sewage system was completed in these areas. The GIS model enables the prediction of the water flow and quality as well as the assessment of the water utilization effects.

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Hydrothermal treatment of biomass to produce useful chemicals has been investigated by many researchers. We proposed a technique to obtain useful chemicals (e.g. sugars, organic acids and furfurals) from biomass feedstock using two-step hydrothermal treatment system which combined steam explosion and hot liquid water reaction. However, a cretin amount of unreacted residue was discharged as wet solid from this system. In this study, hydrothermal carbonization was investigated in order to convert the wet biomass residue into charcoal in liquid phase. If the produced wet charcoal can be used as charcoal water slurry fuel, an efficient energy production system will be attained.
We carried out the hydrothermal carbonization experiment about the residue that is discharged from the proposed two-step hydrothermal treatment of unused forest biomass (e.g. Japanese cedar, bamboo). From the results, it was found that the charcoal obtained by treating at 250°C has higher calorific value of 27∼28 MJ/kg-dry basis. This process is lower temperature that carbonization of biomass usually occur in a hot compressed water. Thus, it has possibility that fuel is produced by inputting a little energy to the biomass residue.

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Trichloroethylene (TCE) had been used as a solvent for dry cleaning and is still used to remove grease from metal parts and so on. However it has recently caused a serious problem that soil and underground water are polluted by TCE. TCE has various effects on human health. For example it may cause headaches, lung irritation, impaired heart function, etc. Therefore TCE concentration in soil is regulated by environmental quality standards for soil and so on. Because of these reasons, purification of contaminated soil or underground water is a matter of great urgency. In situ treatment technologies so far used are mainly bio-remediation and pumping and aeration method. Bioremediation is major method in the United States. But it often causes secondary pollution and it requires long treatment period. In Japan, pumping and aeration method is normally used. But it can't be applied to widespread polluted soil. In situ treatment technologies are required that is applicable to stable pollutants, under various polluted conditions with various ranges of TCE concentration. One of the technologies that satisfy these requirements is chemical oxidation. We noticed Fenton's reaction, which is usually used for oxidation of organic compounds for degradation of TCE. In this study, we investigated the kinetics of degradation of TCE by Fenton's reaction and identified decomposed products. The experiments showed that reaction rate is first-order for TCE and iron, respectively, and half-order for hydrogen peroxide. Major decomposed product was chloride ion, and dichloroacetic acid was slightly produced. In addition we supposed degradation pathway of TCE in Fenton's reaction.

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Zeolites have been synthesized from basic aluminosilicate hydrogel under hydrothermal conditions at elevated temperatures. Since there are various factors affecting zeolite syntheses, the syntheses of zeolite are still based on the experience. Therefore, it is strongly required to understand the crystallization mechanism, resulting in an ultimate goal to synthesize zeolites by rational design. The formation and the consumption of nanosized precursor particles during the synthesis of the nanosized zeolite Linde type A (LTA) from a clear solution using tetramethylammonium (TMA⁺) cation as an organic structure-directing agent (SDA) was studied by in situ small angle X-ray scattering (SAXS) and wide angle X-ray scattering (WAXS). The combination of SAXS and WAXS enables us to observe the particle populations present during the complete course of the crystallization process. Two-sized precursor particles were observed: 2.9nm particles and 11nm particles. The two-sized particles play an important role in the nucleation and the crystal growth of LTA. The size and the distribution of the growing crystals were derived by fitting experimental curves with calculated scattering patterns. A significant narrow size distribution of growing crystals was observed. Based on these findings and further investigations, a mechanism for the formation of organic-mediated nanosized LTA is proposed.

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The WWDJ-batch crystallizer is a newly developed batch crystallizer and equipped with a double-deck jacket and a slurry sprinkler, known as Wall Wetter^TM, that is specially designed for agitating the solution or slurry and sprinkling it on the wall of the crystallizer headspace which is covered by the upper heating jacket. When the slurry is sprinkled to the upper heating wall, fine crystals are dissolved, and consequently, the large crystals with a narrow CSD can be produced. Cooling rate can be precisely controlled based on the three operational parameters, namely the upper and lower jacket temperatures and the rotation speed of the Wall Wetter (the circulation speed of slurry). In this work, we crystallized glycine using the WWDJ crystallizer to show its advantage on the production of large crystals with a high purity and a desired polymorphism.
The 50 % value of the cumulative crystal size distribution of the obtained glycine crystals was 950 µm by WWDJ crystallizer, compared with 480 µm in a crystallization experiment not using the Wall Wetter. Glycine has three crystal polymorphs, namely α-, β and γ-form. When the conventional crystallizer was used, the unstable α-form crystals were always obtained. However, when the WWDJ batch crystallizer was used, the stable γ-form crystals were obtained, and the appearance of polymorphs depended on the cooling rate during the crystallization. Furthermore, glycine was crystallized from the aqueous solution including L-leucine as an impurity. In the WWDJ crystallizer, only 0.52 µg of L-leucine was contaminated in the glycine crystals of 1 mg, while it was 0.75 µg in conventional crystallizer. Therefore, the contamination was reduced about 45% using WWDJ crystallizer. These results shows that the WWDJ batch crystallizer has advantage to control the CSD, purity and crystal polymorphism.

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The concept of the metastable zone or supersolubility was proposed some hundred years ago. The metastable zone width (MZW), the magnitude of the metastable zone, is usually determined as a degree of supercooling at which a first nucleation event is detected on cooling of a solution of a given concentration. It has been long believed that a crystallizer can be operated safely without any nucleation at any supercooling within the metastable zone. It is a question whether this concept can be used really for the design and stable operation of a crystallizer. In this study, it will be explained why the value of the metastable zone width depends on volume and cooling rate. And it will be also shown that the concept of metastable zone can be hardly applied for the design and optimal operation of a crystallizer as opposed to the common belief.

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Calcium carbonate was crystallized by using a specially designed device for crystallization that is a jacketed cylindrical glass tube placed in the lateral and divided into two compartments by a cation-exchange membrane. Solutions of calcium chloride and sodium carbonate were separately placed in each compartment. Calcium ions penetrated into the opposite compartment through the cation-exchange membrane, and there reacted with carbonate ions. Calcium carbonate crystals grew on the surface of cation-exchange membrane and formed cylindrical tubes self-assembled in vertical against the membrane surface. Inner and outer diameter of the cylindrical tube formed at 50°C was about 15 and 30 µm respectively, and the length was 200-400 µm. Most of the calcium carbonate tubes were composed of micro-crystals of the calcite. Micro-crystals of the vaterite also formed cylindrical tubes in particular in the early stage of crystallization.

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The practical application of clathrate crystals for the release control of biocide was investigated. The release of CMI (biocide) was controlled by the formation of clathrate crystals with TEP as the host. The CMI concentration released from TEP-CMI crystals increases with the amount of TEP-CMI clathrate crystals, however, it is limited. The appearance of the peak in the TEP concentration changes is related with the crystal structure change of TEP-CMI crystals. The release mechanism of CMI is cleared to be the combination of the dissolution of TEP-CMI crystal and the crystallization of the new solid phase (TEP-SOL (TEP·CH₃OH·H₂O)). The rate of the structural change remarkably depends on the amount of crystals. The crystal morphology is different between the TEP-CMI crystal and TEP-SOL crystal. The rate of the structural change also decreased with the increase of water composition.When the stirring is sufficiently intensive (450 rpm), the attained CMI concentration becomes higher than that at 250rpm with small magnetic bar. On the other hand, the attained TEP concentration at 450 rpm appeared to be lower than that at 250rpm. It was shown that at 450 rpm the true equilibrium was established between the crystals and the solutions, however, at 250 rpm both concentrations are under the qasi-equilibrium. This may be due to the disturbance of the diffusion of CMI molecule from TEP-CMI crystals by the TEP-SOL crystals which precipitate on the surface of the TEP-CMI crystals. The attained concentration was expressed as the function of the solvent composition. The abnormal concentration change of CMI and TEP was also observed by changing the stirring crate.

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Porous polymer microspheres of poly(methyl methacrylate-co-trimethylolpropane triacrylate)[P(MMA-co-TMPTA)] were prepared by in-situ polymerization using the multiple emulsion (W/O/W emulsion), which was prepared by the two-step emulsification method. TMPTA was added as the cross-linking agent to increase the mechanical strength and the organic solvent-resistant. It was investigated how the conditions at the first step emulsification (W/O), the kinds and concentrations of surfactant in the oil phase and the concentration of salt in the inner water phase affected the morphology and the hollow degree of microspheres. From these results, it was found that oil soluble glycerol surfactant (OSGS) was effective as a surfactant for preparing the W/O emulsion and the finer internal structure of polymer microspheres was formed with the concentration of OSGS in the oil phase. Furthermore, by addition of NaCl into the inner water phase and increasing the concentration of NaCl, the entrapment efficiency of the inner water phase and the hollow degree of microspheres were found to be increased. Furthermore, it was found that the higher hollow degree of polymer microsphere was able to be obtained by increasing the volume ratio of the inner water phase and the stability of the W/O dispersion.

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Micron-sized inorganic microparticles with hollow inside were prepared by interfacial reaction method, in which the ion exchange reaction between Na⁺ and metal cation dissolved in internal and external aqueous phases proceeded through oil phase involving a cation carrier. The diameter of microballoons was about 10 µm and shell thickness was below 2 µm. The effects of preparation conditions against the formation of microballoons were also examined. The factors examined were metal species in external aqueous phase, the concentrations of metal chloride and cation carrier. When the cross-section of resulting microparticles was measured by scanning electron microscope (SEM), the inner space of some metal silicates was not hollow but filled up. The increase of salt concentrations led to the increase of the diameter and shell thickness of microballoons. Since the penetration of metal cation through oil phase was promoted by the increase of carrier concentration, the formation of microballoons was possible in a short time less than 30 min.

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The porous microcapsules were prepared by a in-situ polymerization of styrene and divinylbenzene in the W/O/W (water in oil in water) emulsion system. A large number of spherical pores in the inside and on the surface of the microcapsules were formed. The structure and morphology of the microcapsules was strongly affected by the preparation conditions such as weight fraction of the inner aqueous phase, surfactant and diluent concentrations in the organic phase, and stirring speed in the dispersion of the inner aqueous phase. The diameter and the specific surface area of the microcapsules increased with an increase in the volume fraction of the inner aqueous phase. By increasing the surfactant concentration in the organic phase, the diameter of the microcapsules decreased and the surface area increased.

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Up to now, very few papers already published for the discussion of the relation between operational conditions and the characteristics of produced capsules systematically. The microencapsulation mechanism of in-situ polymerization method also has not been investigated in detail. In this paper, the encapsulation by in-situ polymerization method was focused, and respective effects of operating factors in the encapsulation process on the microcapsules with solid and liquid core were investigated systematically to understand the encapsulation mechanism. Silica particles with narrow size distribution and mono-dispersed kerosene droplets prepared by SPG membrane emulsification method were used as solid and liquid cores, respectively in order to prevent the complicated effect of core size distribution on microencapsulation. They were microencapsulated by in-situ polymerization method under various operating conditions where polymerization temperature, core size, stirring rate and addition time of core material were changed, and the membrane growth and the surface of microcapsules were examined. The relations between the membrane thickness and the circularity of formed capsules and each operational factors were discussed. The microcapsules obtained on solid and liquid cores were also compared.

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In order to obtain the fundamental information required to prepare microcapsules by interfacial polycondensation polymerization, emulsions were made by dispersing limonene oil in the aqueous solution of PVA with different degrees of saponification. The microcapsule was made by polycondensation reaction between isocyanate and amine. We investigated growth speed of the microcapsule wall in polycondensation. And we considered how PVA species with different degree of saponification affected the shell growth of microcapsules.

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Natural rubber (NR) latex consists of natural rubber particles which are mainly cis-polyisoprene and non-rubber substances such as proteins and lipids. NR particles typically exhibit a bimodal curve of particle size distribution. The small particles with submicron size can be obtained by high speed centrifugation. These particles has a point of zero charge at pH about 3.9. This enables NR particles as an amphoteric substance. Cationic surfactant, CTAB, and anionic surfactant, SDS, were selected to adsorb on NR particles at pH 8 and 3 respectively. The results showed that the adsorption isotherm of cationic surfactant is L-shape while it is S-shape for anionic one. The equilibrium time and adsorption isotherms for both conditions were determined by TOC, HPLC, and surface tension. Effect of salt on the adsorption of both surfactants were also included.

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Water-borne associating polymers are defined as polymers which partly associate in water. They not only show unique physical properties in water but also have been found to have some major industrial applications, such as rheological modifiers in paints and coatings formulations. Basically, they consist of a water soluble backbone to which hydrophobic modifiers are attached. In this study, the association behaviors of alkyl-modified poly(vinyl alcohols) and a control polymer were investigated in water and in dimethyl sulfoxide (DMSO). The modified polymers associated with each other in water, while they did not in DMSO. The possibility of controlling the association behavior by changing the solvent composition was demonstrated. The techniques used were pulsed gradient spin echo nuclear magnetic resonance spectroscopy (PGSE NMR) and viscometry.

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Open microcellular foams having small-sized cell and good mechanical properties are desirable for many practical applications. To reduce the cell size of foam, the microcellular foams combining a polybutadiene into the conventional formulation of styrene and water system were prepared via high internal phase emulsion polymerization. Since the material properties of foam are closely related to the solution properties of emulsion state before the polymerization of emulsion into foam begins, the rheological properties of emulsions were investigated using a controlled stress rheometer. The yield stress and the storage modulus increased as the rubber concentration and agitation speed increased, due to the reduced cell size reflecting both a competition between the continuous phase viscosity and the viscosity ratio and an increase of shear force. Based upon the information about rheological properties, the foams were prepared and their morphology and cell sizes were analyzed by a scanning electron microscope. Appreciable tendency was found between the rheological data of emulsions and the cell size change of polymerized foams. The cell size reduction with rubber concentration could be explained by the relation of capillary number and viscosity ratio. A correlative study for the cell size reduction with agitation speed was also attempted and the result was in a good accordance with the hydrodynamic theory.

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The study of waterborne dispersions of polymer resins with zero or low content of harmful organic compounds has much attention due to increasing of environmental and ecological legislative pressures. Waterborne polymer dispersion is a colloidal system of discrete polymer particles disperse in an aqueous continuous medium. Stable aqueous dispersions of polyurethane anionomer were successfully prepared by phase inversion emulsification. Phase inversion is induced by increasing the fraction of the dispersed phase to change the phase ratio in a liquid-liquid dispersion until the dispersed phase become the continuous phase. In this presentation here, water was added to polyurethane anionomer until the water became the continuous phase. As the phase inversion was complete, all water droplets in the system were simultaneously transformed into the continuous phase and discrete waterborne particles of polyurethane were formed. The rheological behaviors, torque change measurements, during the phase inversion process were characterized to detect the phase inversion point. The maximum torque change was considered as the character of phase inversion in the process of emulsification. The effect of stoichiometric formulation and molecular weight of polyol on the particle size and phase inversion behaviors will be discussed.

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In our previous research, a surfactant-lipase complex (lipase complex) that shows high enzymatic activity in organic solvents was immobilized in PEG microsphere using the oil-in-water-in-oil (O/W/O) emulsion. The lipase complex immobilized in PEG microsphere (immobilized lipase complex) exhibited the high enzymatic activity after re-using ten times in organic solvents. In this study, the new method of immobilizing the lipase using the O/W/O emulsion was developed. This new immobilization method do not use the lipase complex. Native lipase is dissolved in PEG buffer solution in the O/W/O multiple emulsion and is immobilized to PEG microsphere during freeze-drying. Native lipase immobilized in PEG microsphere (immobilized native lipase) shows high enzymatic activity that resembled the surfactant-lipase complex and the immobilized surfactant-lipase complex in esterification of lauric acid and benzyl alcohol. Moreover, the high enzymatic activities of the immobilized native lipase were completely maintained also in ten re-using. The performance of the immobilized native lipase showed a heat-resistant property in isooctane. In synthesis of flavor esters, the immobilized native lipase showed the enzymatic activity higher than the lipase complex and the same activity as the immobilized lipase complex. The immobilized native lipase can be a good biocatalyst for the synthesis of flavor esters.

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The aim of this study was to investigate the effect of the composition of formulations on the properties of freeze-dried protein-excipient mixtures. Lysozyme, hyaluronidase, chymotrypsinogen A, and thermolysin were chosen as model proteins. Various excipients, including saccharides and polymers, were used to protect proteins during freeze-drying and subsequent storage. The morphology and surface of freeze-dried mixtures observed by scanning electron microscopy (SEM) displayed quite different morphologies, primarily depending on the excipient and protein used. The effects of excipients on the secondary structure of lyophilized protein were investigated with second-derivative Fourier transform infrared (FTIR) spectroscopic analysis. The glass transition temperature (Tg), denature temperature (Td) and residual moisture content were determined by differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA). The preservation of the secondary structure of protein, Tg and Td were found to be dependent upon the type and amount of excipient included in the formulation.

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This study aims encapsulation of Hem Iron and applying it to the food industry. Hem Iron was encapsulated by a few of fatty acids and fatty acid esters using two kinds of encapsulation methods that are the in-situ method and coacervation method. In these experiments, such preparation conditions as the agitation velocity, the kinds of fatty acids or fatty acid esters, the weight ratio of wall material to Hem Iron, and the concentration of stabilizer were changed stepwise. Capsules were characterized with respect to the capsule diameter, the content of Hem Iron and the encapsulation efficiency. In the first encapsulation method, it was found that increasing the agitation velocity and using casein sodium as stabilizer decreased the capsule diameter. In the second encapsulation method, it was found that the addition of only water phase into suspension resulted in the poor encapsulation efficiency, however the temperature change of suspension after the addition of water phase increased the encapsulation efficiency.

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Gelatin films are used in various fields such as an ideal delivery system for a wide range of medicine, food supplements in convenient and stable form, and a reasonably good stabilizer for various enzymes. Precision control of the surface structure of gelatin films will create new possibilities to the applications. We developed the micropit array, which has uniform quadrangular or circular pits with side length or diameters from 25 to 400µm and depth from 10 to 80 µm as a three dimensional structure. We attempted to use the micropit arrays as a mold in order to control the surface structures of gelatin films. Peeling gelatin cast off from a micropit array, gelatin film was obtained. The uniform cylindrical and cuboidal structures on the surface, which replicated the micropit array, were observed by scanning electron microscope. From these results, the precision control of the surface structure of gelatin films was confirmed to be possible. Analysis on release rate of fluorescein isothiocyanate bovine serum albumin (FITC-BSA) from gelatin films showed that more FITC-BSA was released from the films with cylinders on the surfaces compared with the film with smooth surface. In addition, the release rate of FITC-BSA from the surface with cylinders with diameter 50 µm was greater than that from the surface with cylinders with diameter 400 µm. The results were probably due to difference in the specific surface area of the films. These results imply that precisely designed microstructures on the gelatin surface by micropit array will enable us to control the release rates of pharmaceuticals in gelatin films.

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