Chromium (III) is an inorganic salt being used as corrosion inhibitor plating agents surface treating agents furniture furnishings and textile printing and etc. The discharge of industrial waste water containing chromium (III) into the water source was toxic to the aquatic lives and some parts accumulate in the soil chromium (III) reduces the growth of plants reduced photosynthesis inhibit the enzyme activity imbalanced in plants and reduced productivity and etc. For this reason method to remove it before discharge the effluent into the water source is necessary. The use of apatite materials for adsorption and immobilization of various pollutants was a technique that was more likely to be used.Due to its high adsorbency easy to use and environmentally friendly. The purpose of this research was to study the preparation of calcium hydroxyapatite structural characterization of calcium hydroxyapatite by X-ray diffraction technique adsorption study of chromium solution with calcium hydroxyapatite in various conditions and the determination of adsorption isotherm. The results showed that the optimum contact time of calcium hydroxyapatite and chromium solution was 3 hours. Most adsorption works well at a pH of around 6.76. Considering the amount of chromium (III) adsorbed at equilibrium (q) it was found that the calcium hydroxyapatite with 10 % zinc added that has been calcined to 400 OC and the calcium hydroxyapatite with 15 % zinc added that has been calcined to 800 OC were to adsorb chromium (III) more than other sorbents. The adsorption isotherm was suited with Fruendlich and Langmuir. The calcium hydroxyapatite with 10 % and 15 % zinc added that has been calcined to 400 OC had the highest adsorption capacity (qm) up to 178.57 and 181.82 mg/g respectively. In addition it was found that calcium hydroxyapatite which heated to 800 degrees Celsius can decompose tricalciumphosphate.

The aim of this work was to fabrication of Hydroxyapatite Glass-ceramic by adding ZrO2 for Dental Application. The glasses were prepared by conventional melting of the coprecipitation derived starting products and heat treated at different temperatures. The structure mechanical properties and microstructure of the samples were characterized by X-ray diffraction Vicker hardness energy dispersive X-ray analysis (EDXA) and scanning electron microscopy. The data showed that the samples with condition Li1-1450 and heated treatment at 830 C having high strength and proper crystallinity showed good translucency which comparable with that of the sample from factory. XRD analysis revealed XRD analysis revealed that the peak corresponds to the crystallization of Li2SiO3 SiO2or Li6SiO8which are important phases have effect to increasing the mechanical properties of samples.

In this work the objective is to develop the bilayer structure consisting of hydroxyapatite-alumina (HAp-Al2O3) layer and 3 mol% yttria tetragonal zirconia (TZ-3Y) layer using conventional technique consisting of the simple pressing together with pressureless sintering. In order to obtain the desired characteristics of bilayer structure layer thickness cosintering temperature and Al2O3 addition on successful fabrication of HAp-Al2O3/TZ-3Y bilayer structure are investigated. The results indicated that the HAp-10A/TZ-3Y bilayer structure was successfully fabricated by single-end die pressing the powders in hollow cylindrical graphite die under 60 MPa pressure and further wet-bag isostatically pressing in oil to 300 MPa pressure before sintering at 1200 ˚C for 1 h. It is found that an addition of 10 vol% Al2O3 into the HAp outerlayer is the essential condition to effectively suppress the differences in densification and coefficient of thermal expansion of the two layers during cosintering at 1200 oC for 1 h. The obtained HAp-10A/TZ-3Y bilayered disc has diameter of 21.0 mm HAp-10A outerlayer of 4.5 mm thick and TZ-3Y underlayer of 2.5 mm thick. The XRD pattern of the powders crushed from its HAp-10A outerlayer revealed no transformation into other new phases demonstrating that there is no reaction between HAp and Al2O3 during sintering at 1200˚C. The cross-section morphology of HAp-10A/TZ-3Y bilayered composite obtained from the SEM result revealed the porous structure with good interconnectivity. The high porous structure of the bilayered composite provided high surface area for cell attachment indicative of good cell growth and differentiation. The primary grain sizes of HAp-10A outerlayer and TZ-3Y underlayer were in the range of 1-3 um and 100-500 nm respectively. The hardness of HAp-10A layer and /TZ-3Y layer in bilayer structure varied with different layer thicknesses. Accordingly the results presented in this work demonstrated that the HAp-10A/TZ–3Y bilayered composite fabricated by simple technique has thick HAp-Al2O3 outerlayer and strong interfacial bonding between interface layers which can be tailored for specific applications

A promising composite of zinc ferrite (ZnFe2O4) and bioactive hydroxyapatite (Ca10(PO4)6(OH)2 ;HAp) has expected to potential for future bone reinforcing formation. In present study zinc ferrite and hydroxyapatite composite was prepared by solid state reaction route for easier control of structural and magnetic characteristics and with low cost. Hydroxyapatite powder was synthesized by precipitation method from chicken eggshell. Mixed powders with varying ZnFe2O4/HAp weight ratios from 2-10 wt% were milled together and uniaxially pressed and then sintered at 1200 oC for 3 hours. The XRD results showing no other phases of composite with only HAp and ZnFe2O4 phases were identified indicating high stability of HAp property. Phase fractions of ZnFe2O4 were found to increase from 10.8 to 18.73 wt% with increasing content of ZnFe2O4. FT-IR results of ZnFe2O4/HAp composite were only revealed vibration bands of standard HAp phase. This may due to the overlapping of the ZnFe2O4 vibrational bands with HAp bands. However their intense variations observed in HAp vibrational bands indicated the interaction between ZnFe2O4 and HAp. The surface morphology of these ZnFe2O4/HAp composite exhibited primary grain in nano scale with enhanced pore structure and Interconnectivity when ZnFe2O4 weight ratios increased; indicating high surface area for cell attachment and better good cell growth and differentiation. The higher saturation magnetization as well as higher super paramagnetic behavior could be easily altered by increasing ZnFe2O4 content in the composite.