The present work was made to investigate preparation of hardened body from reclaimed gypsum hemihydrate obtained by dry or wet process of waste board for resources recycling of waste gypsum board. The gypsum dihydrate powder which was separated as much as possible lining paper from the waste board, was separated in two kinds of 2mm pass and 300μm pass by sieving. The dry process was performed by heating the gypsum powder at 200°C for 10 minutes, while the wet process was aged the powder for 60 minutes in 12% H₂SO₄ solution. The use of reclaimed gypsum hemihydrate after dry process was effective by mixing it in calcined gypsum. For example, the strength of the hardened body prepared with equal quantities of the reclaimed hemihydrate and calcined gypsum was almost the same that of independently calcined gypsum. By controlling water carrying capacity and particle size of the reclaimed hemihydrate containing a type of about 25% after wet process, the compressive strength of the hardened body was increased till 110kgf/cm².

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It is very important problem for the utilization of waste bottle glass which is discharged a large quantity, and will be increasing. The best method of utilization of it is considered to use for resource of construction materials. In this study, portland cement paste in the addition of waste bottle glass powder was cured in a saturated water vapor at 20°C. The effects of the addition of waste bottle glass powder on the hydration of portland cement and behavior of alkali component in the glass were discussed to measure the reaction ratio of alite, reaction products, amount of produced calcium hydroxide, reaction ratio of the glass and amount of alkali which was soluble in water. The results obtained are as follows.
1) Waste bottle glass powder has a pozzolanic reactivity when it is used for the admixture of portland cement.
2) The pozzolanic reactivity of waste bottle glass powder is consider to larger than that of fly ash, but smaller than that of granulated blustfurnace slag.
3) Waste bottle glass powder accelerates the hydration rate of alite in the portland cement. This effect is increased with the content of glass.
4) The reaction rate of glass is controlled by the dissolution rate of glass at the initial stage, and then controlled by the diffusion through the hydration layer of glass at the later stage.
5) More than half amount of the sodium component containing in the reacted glass is existed in the water soluble state in the hardened cement.
6) There is possibility to take place the alkali aggregate reaction, because the amount of water soluble sodium component increases in the hardened cement with curing time. It will be needed to take care the reaction to utilization of waste bottle glass for the admixture of cement.

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The present work was investigated about the removal conditions of protein and powder property of low crystalline hydroxyapataite (HAp) obtained by removing protein in NaOH solution for purpose of resources recycling on HAp and protein in bovine bone. The product was characterized by means of X-ray diffraction, thermal analysis (TG-DTA), measurement of BET specific surface area, scanning electron microscopic observation, ultraviolet absorptiometry and chemical analysis.
The removal of protein in bovine bone was carried out suspension concentration of 0.5-10.0 wt% by adding the crushed bone with particle size of below 2mm in 0.1-5.0 wt% NaOH solution at 25°C and 90°C. The removal ratio of protein had a maximum amount under conditions of suspension concentration of below 3.0 wt% by adding the crushed bone in 3.0 wt% NaOH solution at 90°C for 3 hours. The pore volume of low crystalline HAp obtained by removing protein in 5.0 wt% NaOH solution at 25°C, was increased and the HAp was superior to crushability. On the other hand, the Ca/P atomic ratio in reclaimed HAp was increased by removing protein in 5.0 wt% NaOH solution at 90°C. The low crystalline HAp had a very high ion exchange capacity.

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In recent years, leachable toxic heavy metals in incineration residues is a serious problem with regard to ash management. The use of chemical amendments to precipitate toxic heavy metals in fly ash as insoluble solid phases has become of interest.
So the authors have synthesized calcium hydroxide with high surface area (HSA) and phosphorus-containing calcium hydroxide with high surface area (HSAP-a, HSAP-b). The reaction characteristics of the new complexes for lead ions in lead chloride aqueous solutions have been investigated using a normal batch method at room temperature.
The orders of the reaction rates were found to be as follows; HSAP-b>HSAP-a>HSA in acidic region, HSAP-b=HSAP-a=HSA in neutral or alkaline region. It was found that the immobilization characteristics for lead ions are depend on the amount of phosphorous in the complexes in acidic solution.
From the results, it was concluded that the new phosphorus-containing calcium hydroxides with high surface area are effective for immobilization of lead ions, especially, in acidic region.

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Simultaneous adsorption removal of NH₄⁺ ion and PO₄^3-ion was experimentally investigated with a bench scale apparatus of an adsorption-membrance separation hybrid system using the mixed adsorbent of nature zeolite and activated alumina.
Using an adsorbent only, even the membrane permeation did not changed in the presence of both NH₄⁺ ion and PO₄^3-ion. However, the membrane permeation and removal efficiency of each ions were strongly influenced by the kind of adsorbents and its combination. Using the mixed adsorbent of nature zeolite and activated alumina, in particular, the adsorption rate was fast and the adsorption ion concentration rapidly reached up to the equilibrium concentration of each ions.
The adsorption-membrance separation hybrid system reported in this paper is useful for the simultaneous adsorption removal of nitrogen and phosphorus in water.

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A natural zeolite modified by a magnesium ion-exchange method removed simultaniously both. NH₄⁺ and PO₄^3-ions from the solution containing these ions. The cation exchange reaction between NH₄⁺ion and Mg²⁺ion took place on the modified zeolite, and then the precipitation reaction between the desorped Mg²⁺ions from the zeolite and PO₄^3-ions occurs to form water-insoluble MgHPO₄·3H₂O. It was extremely difficult to remove PO₄^3-ions from solutions without NH₄⁺ ions.

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