Environmental Technologies Research Center, Ahvaz Jundishapur University of Medical Sciences, Ahvaz, Iran; Department of Environmental Health Engineering, School of Health, Ahvaz Jundishapur University of Medical Sciences, Ahvaz, Iran E-mail:
Department of Environmental Health Engineering, School of Health, Ahvaz Jundishapur University of Medical Sciences, Ahvaz, Iran E-mail:
Water Sci Technol. 2017 Apr;2017(1):36-47. doi: 10.2166/wst.2018.080.
Metronidazole (MNZ) is a major threat to the ecosystems and human health, due to its toxicity and carcinogenic nature. The main aim of this study was to evaluate the efficiency of graphene oxide functionalized β-cyclodextrin/Ag nanocomposite (GO/β-CD/Ag) for MNZ removal from aqueous solution. The effect of operational parameters such as solution pH (2-5), adsorbent dosages (0.2-1 g/L), contact time (10-80 min), initial MNZ concentrations (0.25-10 mg/L) and ionic strength (0.001-0.1 mol/L) was studied using Taguchi experimental design. The maximum removal efficiency of 93.5% was observed for optimum conditions. The optimum values of contact time, the initial MNZ concentration, the ionic strength, the adsorbent dosage and solution pH were found to be 20 min, 0.25 ppm, 0.01 mol/L, 0.4 g/L and 2, respectively. Freundlich and Dubinin-Radushkevich isotherm models were best-fitted with experimental data. Pseudo-first order and type 1 pseudo-second order kinetic models showed the maximum correlation with the experimental data. Adsorption experiments with real samples indicated that the adsorptive removal of MNZ from a hospital wastewater was 72%. Desorption studies showed maximum recovery of GO/β-CD/Ag nanocomposite during three cycles. According to the obtained results, it can be concluded that the application of carbon adsorbents such as GO/β-CD/Ag can be considered an efficient method for final treatment of effluents containing antibiotics.
甲硝唑（MNZ）由于其毒性和致癌性，对生态系统和人类健康构成了重大威胁。本研究的主要目的是评估氧化石墨烯功能化β-环糊精/Ag 纳米复合材料（GO/β-CD/Ag）对水溶液中 MNZ 的去除效率。通过 Taguchi 实验设计研究了操作参数（pH 值为 2-5、吸附剂用量为 0.2-1 g/L、接触时间为 10-80 min、初始 MNZ 浓度为 0.25-10 mg/L 和离子强度为 0.001-0.1 mol/L）对去除效率的影响。在最佳条件下，观察到最大去除效率为 93.5%。接触时间、初始 MNZ 浓度、离子强度、吸附剂用量和溶液 pH 的最佳值分别为 20 min、0.25 ppm、0.01 mol/L、0.4 g/L 和 2。Freundlich 和 Dubinin-Radushkevich 等温模型最适合实验数据。准一级和一级伪二级动力学模型与实验数据具有最大相关性。实际样品的吸附实验表明，从医院废水中吸附去除 MNZ 的效率为 72%。解吸研究表明，GO/β-CD/Ag 纳米复合材料在三个循环中可实现最大回收率。根据获得的结果，可以得出结论，应用 GO/β-CD/Ag 等碳吸附剂可以被认为是处理含有抗生素的废水的最终有效方法。
