Abstract

• Using the wet precipitation method, hydroxyapatite, Ca10(PO4)6(OH)2, was synthesized from waste crab shells in this study. The prepared hydroxyapatite and titanium dioxide with cement have been fabricated by blending to form a hydroxyapatite-cemented titanium dioxide composite at room temperature. The photodegradation capacities of composites in solar light and in the dark were studied for the degradation of dye (methylene blue) solutions with varying parameters of initial concentration of dye solution and contact time at optimal conditions. The results show that the kinetic study of the photodegradation reaction follows the Langmuir-Hinshelwood model equation. SEM technique was applied to characterize the prepared hydroxyapatite-cemented titanium dioxide composite. According to the SEM analysis, it was found that the pores of the composite were filled after the degradation of the dye. The photodegradation of contaminants in water collected from a fish pond near Shwedagon Pagoda was studied using composites. Composite was also found to be the most efficient and effective adsorbent for the degradation of organic pollutants from wastewater. As a result, the prepared hydroxyapatite-cemented titanium dioxide composite can be applied to the reduction of organic pollutants discharged from wastewater into aquaticenvironments. It would help reduce the public health risk caused by organic pollutants.