Abstract:
Eggshell has as an important constituent pure CaCO3 and a little developed porosity. Its composition has been reported chemically (by weight) as follows: calcium carbonate (94%), magnesium carbonate (1%), calcium phosphate (1%) and organic matter (4%) [1]. Application of eggshell wastes was mentioned before as a biodiesel catalyst. [2,3]
It is also reported to be used as an absorbent of heavy metals from wastewater as it is a serious environmental problem in the ecosystem. It is also reported to be used in the formation of hydroxyapatite, a biomaterial used to replace or repair bone tissues and as fertilizers and calcium supplements in nutrition for human, animals, plants, etc.
The egg shells were calcined and chemically treated to obtain calcium nitrate. The calcium nitrate was processed further with ammonium oxalate to obtain calcium oxalate.
In the second part of the experiment, the calcium nitrate was treated with Diammonium hydrogen phosphate to obtain hydroxyapatite under basic condition. The synthesized materials were characterized for its purity using XRD, FTIR. They were further characterized for particle size and microstructural analysis by FESEM. The characterization shows the formation of calcium oxalate and hydroxyapatite particles.
Hydroxyapatite, [Ca10(PO4)6(OH)2, (HAp)] is widely used in medical fields especially as a bone and teeth substitute. In the present work, Hydroxyapatite nanoparticles have been successfully synthesized from egg shells as a source of calcium by using sol-gel method. The synthesized hydroxyapatite biomaterial was characterized using FTIR. The XRD patterns showed that the products were hydroxyapatite crystals.
