Nano-hydroxyapatite was synthesized by coprecipitation method and tested its antibacterial properties. Nano-hydroxyapatite was synthesized using CaO precursors from snakehead (Channa striata) fish bones and (NH4)2HPO4. The synthesis was carried out with temperature variations of 30, 60, 80, and 100 °C. Antibacterial activity was determined using two types of bacteria, namely gram-positive and gram-negative. The XRD spectra show that the highest peak is hydroxyapatite synthesized at a temperature of 100 °C. Hydroxyapatite produced from various synthesis temperatures has the size of nanoparticles in the range 37.32-49.27 nm. The nano-hydroxyapatite functional groups are characterized using FTIR, the analysis indicate the presence of OH, CO32‒ and PO43‒. The molar ratio Ca/P is obtained of 1.71 approaching theoretical hydroxyapatite of 1.67. The resulted nano-hydroxyapatite has significant antibacterial properties to Escherichia coli and Staphylococcus aureus.

Biomaterial exploration base on solid waste has been an attractive issue, particularly regarding economic and environmental demand. This work aimed to extract hydroxyapatite from snakehead fishbone through precipitation method and used to remove Ni(II). The hydroxyapatite product was characterized by using X-ray Diffraction (XRD), Fourier Transform Infrared spectroscopy (FTIR), Scanning Electron Microscope-Energy Dispersive Spectroscopy (SEM-EDS) and Brunauer Emmett Teller (BET) method. Batch adsorption experiment includes pH solution, contact time and Ni(II) concentration. Pseudo-first order and pseudo-second-order were used to investigate the reaction mechanism and kinetic model, while adsorption equilibrium was evaluated according to Langmuir and Freundlich isotherm. XRD and FTIR spectra confirmed that hydroxyapatite was successfully extracted. The molar ratio (Ca/P) of hydroxyapatite was found at 1.70. The particle size of the hydroxyapatite was 48.77 nm. The pseudo-second-order is appropriate to describe the kinetic model while the adsorption mechanism follows Langmuir isotherm, which has an adsorption capacity of 5.359mg/g. The thermodynamic evaluation suggested the adsorption of Ni(II) is spontaneous in the endothermic process.

Snakehead Fish Bone (SFB) is a waste from food processing in Palembang. Fish bones have calcium content so they have a potential as a source of Calcium Oxide (CaO). Calcination of fish bones was carried out at a temperature of 900 o C with variations of time 1, 2, 3, and 4 hours. The Nanoparticle Calcium Oxide (NCO) was prepared using the ball milling method. This study aims to make NCO as a raw material for hydroxyapatite synthesis. The NCO was characterized using Fourier Transform Infra-Red (FTIR), X-Ray Diffraction (XRD), and Scanning Electron Microscope (SEM). Characterization using FTIR shows that NCO has functional groups O-H, CO 3 2and PO 4 3functional groups. XRD analysis shows that NCO has an average particle size of 38.9445 nm. Analysis using SEM shows particles in the form of granules of almost uniform size. The NCO produced eligible of the nanomaterial and has the potential as a raw material for synthesis of hydroxyapatite.