"Gheorghe Asachi" Technical University of Iasi, Prof. dr. docent Dimitrie Mangeron Rd., no. 73, Iasi 700050, Romania.
"Gheorghe Asachi" Technical University of Iasi, Prof. dr. docent Dimitrie Mangeron Rd., no. 73, Iasi 700050, Romania.
Sci Total Environ. 2018 Jul 1;628-629:36-43. doi: 10.1016/j.scitotenv.2018.02.027. Epub 2018 Feb 13.
The presence of antibiotics in the water and wastewater has raised problems due to potential impacts on the environment and consequently their removal is of great importance. For this reason, this article aims to perform a study on the possibility of oxytetracycline (OTC) adsorption from aqueous medium by using the hydroxyapatite (HA) nanopowders as adsorbent materials. The hydroxyapatite nanopowders were synthesized by wet precipitation method by using orthophosphoric acid and calcium hydroxide as raw materials and investigated by XRD, SEM-EDX, FTIR and BET methods. The uncalcined and calcined hydroxyapatite samples have hexagonal crystal structure with crystal sizes smaller than 100nm and a specific surface area of 316m/g and 139m/g, respectively. The adsorption behavior of oxytetracycline, a zwitterionic antibiotic, on nanohydroxyapatite was investigated as a function of pH, contact time, adsorbent dosage and drug concentration by means of batch adsorption experiments. High oxytetracycline removal rates of about 97.58% and 89.95% for the uncalcined and calcined nanohydroxyapatites, respectively, were obtained at pH8 and ambient temperature. The adsorption process of oxytetracycline onto nanohydroxyapatite samples was found to follow a pseudo-second order and intraparticle diffusion kinetic models. The maximum adsorption capacities of 291.32mg/g and 278.27mg/g for uncalcined and calcined nanohydroxyapatite samples, respectively, have been found. The adsorption mechanism of OTC on the hydroxyapatite surface at pH8 can be established via surface complexation. The obtained results are indicative of good hydroxyapatite adsorption ability towards oxytetracycline drug.
水中和废水中抗生素的存在引发了一系列问题，因为它们可能对环境造成影响，因此去除抗生素非常重要。出于这个原因，本文旨在研究使用羟基磷灰石（HA）纳米粉末作为吸附材料从水溶液中吸附土霉素（OTC）的可能性。羟基磷灰石纳米粉末通过湿沉淀法使用正磷酸和氢氧化钙作为原料合成，并通过 XRD、SEM-EDX、FTIR 和 BET 方法进行了研究。未煅烧和煅烧的羟基磷灰石样品均具有六方晶结构，晶粒尺寸小于 100nm，比表面积分别为 316m/g 和 139m/g。通过批处理吸附实验，研究了两性抗生素土霉素在纳米羟基磷灰石上的吸附行为，作为 pH、接触时间、吸附剂用量和药物浓度的函数。在 pH8 和环境温度下，未煅烧和煅烧纳米羟基磷灰石对土霉素的去除率分别高达约 97.58%和 89.95%。土霉素在纳米羟基磷灰石样品上的吸附过程符合准二级和内扩散动力学模型。未煅烧和煅烧纳米羟基磷灰石样品的最大吸附容量分别为 291.32mg/g 和 278.27mg/g。在 pH8 下，土霉素在羟基磷灰石表面的吸附机制可以通过表面络合来建立。这些结果表明羟基磷灰石对土霉素药物具有良好的吸附能力。
