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This study focused on identifying the Cl-bearing phases in fly-ash after the washing treatment. The influence of carbonation was also considered, which was hypothesized to decompose the insoluble chlorine in the ash products. Four samples (A-o,A-w,B-o,B-w) were investigated before and after washing (O:original, W:washed). XRD and SEM-EDX were used to determine the mineralogical content and elemental composition in the samples. XRF was also employed to determine the bulk chemistry of the ash products. The results verified that soluble chlorine decreased after the washing process while the insoluble chlorine could not be removed. Therefore it might have been fixed in some stable phases such as Friedel’s salt. Carbonation experiment was conducted in all the samples to evaluate any possible changes in the insoluble chlorine. Upon carbonation, the insoluble chlorine ratio considerably decreased that indicates the influence of carbonation process on the decomposition of Cl-bearing stable phases. However the insoluble chlorine could not be completely converted into soluble state after carbonation which is indicative of the existence of other stable Cl-bearing phases in the wood fly-ash. This needs to be investigated with further details.

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Seagrass beds and tidal flats are facing massive destruction and so it is highly desirable to restore and conserve them. Steel slags from steelmaking processes are some of the promising alternative materials for marine sands useful for restoration. The release of calcium and alkalis caused by the hydrolysis and elution of calcium oxide from the slags constituted the main reaction arising from aging processes in the marine environment, and it promotes the separation of magnesium hydrate and calcium carbonate and the solidification by pozzolanic reaction. The significant pH increase and solidification would have negative impact on biological activities. However, the mechanism of solidification and the effect of contact ratio of seawater with slag are not fully understood. Therefore, this study aimed to reveal the mechanism of solidification in seawater and the effect of contact rate with seawater. The result indicates that the solidification is affected by the contact speed of seawater, and would be caused by the products with the hydrolysis of magnesium, the calcium oxide and silicate salts produced by  pozzolanic reaction in alkaline condition.

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This study was made for the purpose of designing and manufacturing shield concrete effectively and demonstrating its performance. Shield concrete may be used at various sites to protect people who work for the recovery from the Great East Japan Earthquake against radiation.We produced the high density shield concrete which is about 30 percent higher than normal concrete in density. This high density concrete was made of electric furnace slag aggregate, in view of environmental and economical aspects.Simulation analysis for shield effect prediction presented that the surrounding radiation was not negligible and shielding effect of high density concrete was about 50 percent higher than the normal concrete.We will verify this simulation results from data measured on site and increase the accuracy to improve the technique of predicting and designing radiation shield.

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When byproducts/recycled materials such as waste concretes, slags, coal ash and so on are used in civil engineering work, they have a potential to release the chemical substances and contaminate the surrounding environment. Chemical amounts leaching from the byproducts/recycled materials are dependent on rainfall intensity and geological properties. Investigating the factors that affect the chemical leaching amounts is important for safety evaluation and promotion of the byproducts/recycled materials according to the application environments. In particular, the effects of the rainfall intensity on the chemical leaching amounts should be clarified to widely use and design the byproducts/recycled materials among the countries which have different climate and rain. In this study, the serial batch tests with different stirring velocity levels were conducted and clarified the relationships between the chemical leaching amounts and the fluid velocities.

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To promote the recycling of incineration ash for cement material, chloride concentration in the ash should be kept low level, because the acceptable ash has been limited by the capacity of the chlorine bypass system in the cement clinker production process. In this study, removing chloride from municipal solid waste incineration ashes by aqueous washing has been examined. The results show that water soluble chloride removes from ash to solution easily, the Friedel’s salt (3CaO-Al2O3-CaCl2-10H2O), however, difficult to remove and contents of  Friedel’s salt percentages are 20-36% in bottom ash and 23% in  fly ash.  It is also shown that the behavior of heavy metals such as Cr, Cu, Zn, Cd, Hg, Pb, in rinsing process has been studied.  Furthermore, the closed regeneration system of rinsed aqueous waste has been discussed.

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Recycling of by-product salt from waste treatment procecesses such as incinerator, melting furnance, leachate etc, will be presented to produce eco-NaClO by electrodialysis. This time, newly investigated themes (refreshing method ofelectrodialyser, relationship of liquid concentration vs efficiency, method to reduce deterioration of produced NaClO), and a proposal to use produced eco-NaClO for sewage treatment, will be reported. 

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In order to remove cesium ion from sea water, the adsorbent was synthesized from inorganic wastes such as oyster shells, drinking–water-treatment sludge (DWTS), and waste glass. The removal percentage for cesium ion was 72% in sea water.The proposed adsorbent showed faster adsorption rate than natural zeolite.

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This paper reports and discusses the test results of pyrolysis liquefaction process using catalytic-cracking method fed by the mixed plastics from the waste household electrical  appliances containing five kinds of cheap general-purpose resins (PP, PS, ABS, PVC & PUR). This technology realizes a closed recycling system for waste plastics. And, discusses the result of LCA analysis.  

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In recent years, recycling of waste PET has attracted much attention in the point of view of resources saving. We have been investigating about chemical decomposition of PET using microwave heating recently. Under microwave irradiation, alkali decomposition of PET was accelerated by using glycol solvents with high

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Steam gasification of phenol board in the presence of molten carbonate was studied to convert plastic in e-waste into clean fuel gas and to recover useful metals effectively. In the steam gasification of phenol board, conversion of tar and char to gaseous products was accelerated significantly by the carbonate. When the phenol board pulverized to less than 0.15 mm was gasified, carbonate and steam infiltrated enough into the sample particle, and the gasification was shown by homogeneous kinetic model assuming pseudo-first-order reaction. On the other hand, when relatively large phenol board particle was used, two different gasification processes to produce hydrogen were observed. From the observed rate of hydrogen formation, we estimated that the initial gasification occurred in the surface layer in which carbonate and steam infiltrated, and after the layer was consumed, the gasification proceeded on the surface of char.  

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The significant amount of waste tire is discharged. In order to utilize this waste tire, carbonization technique was tested aiming for recovering an automobile fuel. In this experiment, 20 to 50 kg of waste tire was treated in 300 degree in cabonization oven, 20 to 30% of them was recovered as oil. The recovered oil showed almost same performance compared conventional light oil in driving test using diesel truck.

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We measured physical properties of molecular dynamics on the egg shell membrane, which was injected photo functional molecules using adsorption property of the membrane, to utilize food waste as biodegradable functional materials. Reversible color change was observed on the membrane upon irradiation with light of the appropriate wavelength into egg shell membrane which supported photochromic molecules using organic solvent. This membrane is natural porous material composed of proteins. Therefore, we invested adsorbed condition of various dyes to apply to the photo-recording materials which were environmentally safe.

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