海岸带环境过程实验室知识库

(1) 东南大学能源与环境学院

The nano-Mg(OH)_2 with different morphologies was prepared by the chemical precipitation using magnesium chloride and natural bischofite obtained from the Qarhan Salt Lake as the raw material, respectively. The surface morphology, crystal structure and surface functional group of the synthesized catalysts were characterized by scanning electron microscope, X-ray diffraction and Fourier transform infrared spectroscopy. The obtained materials were firstly used for the catalytic ozonation process. The degradation and mineralization of metronidazole by two nano-Mg(OH)_2 catalysts [Mg(OH)_2-1 and Mg(OH)_2-2] with different morphologies were investigated. The results showed that the degradation and mineralization efficiency of metronidazole in the single ozonation process within 10min reached 51.9% and 17.4%, respectively. The addition of Mg(OH)_2-1 or Mg(OH)_2-2 into the ozonation system caused a significant improvement for the removal and mineralization efficiency of metronidazole. The catalytic ozonation performance of Mg(OH)_2-2 was better than that of Mg(OH)_2-1. The pseudo-first order kinetic model had a good fitness (R2>0.97) for the removal of metronidazole in the single ozonation process, Mg(OH)_2-1 catalytic ozonation process and Mg(OH)_2-2 catalytic ozonation process. In addition, the stability and reusability of these two different nano-Mg(OH)_2 catalysts were also evaluated. The results indicated that these two nano-Mg(OH)_2 still maintained high metronidazole removal efficiency even after six repeated runs. Therefore, the synthesized nano-Mg(OH)_2 with different morphologies will be a promising ozonation catalyst for the removal of antibiotics.

采用化学沉淀法分别以六水合氯化镁和取自察尔汗盐湖的天然水氯镁石为原料制备了不同形貌的纳米Mg(OH)_2催化剂,通过扫描电子显微镜、X射线衍射、傅里叶变换红外光谱等手段对所合成的催化剂的表面形貌、晶体结构和表面官能团等性质进行了表征。将两种不同形貌的纳米Mg(OH)_2材料首次应用于催化臭氧化过程,研究了两种不同形貌的纳米Mg(OH)_2[Mg(OH)_2-1和Mg(OH)_2-2]催化剂对甲硝唑的降解和矿化能力。结果表明,在单独臭氧化过程中,反应10min时甲硝唑的降解和矿化效率均较低,分别为51.9%和17.4%,而在臭氧化系统中分别加入Mg(OH)_2-1和Mg(OH)_2-2,甲硝唑的去除效率和矿化效率均明显提高,且Mg(OH)_2-2的催化臭氧化性能要优于Mg(OH)_2-1。另外,单独臭氧化过程、Mg(OH)_2-1催化臭氧化以及Mg(OH)_2-2催化臭氧化过程中甲硝唑的降解均较好地符合伪一级动力学反应模型(R2>0.97)。除此之外,对这两种不同形貌的纳米Mg(OH)_2催化剂的稳定性进行了考察,结果表明,催化剂在循环使用六次后对甲硝唑仍有较高的催化臭氧化去除效率。因此,所合成的两种形貌的纳米Mg(OH)_2催化剂将是一种很有前景的、能用于去除抗生素的臭氧化催化剂。