Fish-scale waste is rich in biocompatible hydroxyapatite (HAp). In the present study, an environmentally friendly method of extracting HAp from fish-scale waste was developed in an effort to promote environmental sustainability. Deep eutectic solvents (choline chloride/glycerol, 1/2) were used to extract HAp from bighead carp (Aristichthys nobilis) scales. A relatively high extraction rate of 47.67% ± 1.81% was obtained under optimum conditions (70 °C, a solid/liquid ratio of 1/15 g/g and a 2.5 hr extraction time). The obtained HAp was characterized and its purity was determined using Fourier transform infrared spectroscopy and X-ray diffraction, respectively. The chemical composition was performed by energy-dispersive X-ray spectrometry and inductively coupled plasma-optical emission spectroscopy. Its morphology and particle size were observed using scanning electron microscopy and particle size distribution analysis. Thermogravimetric analysis was used to determine its thermal stability. Blood compatibility was determined using a hemolytic test. The results showed that this extraction yielded HAp with the irregular morphology, the higher Ca/P ratio, good thermal stability, and blood compatibility, indicating that the proposed method is an excellent alternative for the improved utilization of fish scale waste. PRACTICAL APPLICATION: Biocompatible hydroxyapatite (HAp) was extracted from fish scale (FS) waste by using an environmentally friendly deep eutectic solvent. The optimized extraction and structure characterization of extracted HAp were investigated in this study. The results showed that the extracted HAp had the irregular morphology, the higher Ca/P ratio, good thermal stability, and blood compatibility, which indicated that the proposed method was an excellent alternative to improving the utilization of FS waste.

中文翻译：

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使用深共熔溶剂从鳙鱼鳞片中强化提取羟基磷灰石

鱼鳞废料富含生物相容性羟基磷灰石 (HAp)。在本研究中，开发了一种从鱼鳞废物中提取 HAp 的环保方法，以促进环境的可持续性。使用深共熔溶剂（氯化胆碱/甘油，1/2）从鳙鱼（Aristichthys nobilis）鳞片中提取 HAp。在最佳条件下（70 °C，固液比为 1/15 g/g，提取时间为 2.5 小时）获得了相对较高的提取率，为 47.67% ± 1.81%。对获得的 HAp 进行表征，并分别使用傅里叶变换红外光谱和 X 射线衍射测定其纯度。通过能量色散 X 射线光谱法和电感耦合等离子体光发射光谱法测定化学成分。使用扫描电子显微镜和粒度分布分析观察其形态和粒度。热重分析用于确定其热稳定性。使用溶血试验确定血液相容性。结果表明，这种提取得到的 HAp 具有不规则形态、较高的 Ca/P 比、良好的热稳定性和血液相容性，表明该方法是提高鱼鳞废物利用率的绝佳替代方法。实际应用：使用环保的低共熔溶剂从鱼鳞 (FS) 废物中提取生物相容性羟基磷灰石 (HAp)。本研究对提取的 HAp 的优化提取和结构表征进行了研究。结果表明提取的HAp具有不规则的形态，