Key Laboratory of Northwest Resource, Environment and Ecology, MOE, Xi'an University of Architecture and Technology, Xi'an 710055, China; Shaanxi Key Laboratory of Environmental Engineering, Xi'an University of Architecture and Technology, Xi'an 710055, China.
Key Laboratory of Northwest Resource, Environment and Ecology, MOE, Xi'an University of Architecture and Technology, Xi'an 710055, China; Shaanxi Key Laboratory of Environmental Engineering, Xi'an University of Architecture and Technology, Xi'an 710055, China.
J Environ Sci (China). 2018 Oct;72:89-97. doi: 10.1016/j.jes.2017.12.014. Epub 2018 Jan 4.
Two types of filter media in groundwater treatment were conducted for a comparative study of surface structure and catalytic performance. Natural filter media was adopted from a conventional aeration-filtration groundwater treatment plant, and active filter media as a novel and promising filter media was also adopted. The physicochemical properties of these two kinds of filter media were characterized using numerous analytical techniques, such as X-Ray diffraction (XRD), scanning electron microscope (SEM), energy dispersive X-ray (EDX), X-ray photoelectron spectroscopy (XPS) and Zeta potential. The catalytic activities of these filter media were evaluated for ammonium and manganese oxidation. XRD data showed that both active filter media and natural filter media belonged to birnessite family. A new manganese dioxide (MnO) phase (PDF#72-1982) was found in the structure of natural filter media. The SEM micrograph of natural filter media showed honeycomb structures and the active filter media presented plate structures and consisted of stacked particle. These natural filter media presented lower level of some trace elements such as calcium and magnesium, lower degree of crystallinity, lower Mn(III) content and lattice oxygen content than that of active filter media, which were associated with its poor ammonium and manganese catalytic activities. In addition, some γ-FeO and MnCO were found in the coating which may hinder the ammonium and manganese catalytic oxidation. This study provides a thorough and comprehensive understanding about the most commonly used filter media in water treatment, which can provide a theoretical guide to practical applications.
对地下水处理中的两种过滤介质进行了比较研究，以考察其表面结构和催化性能。采用了传统曝气-过滤地下水处理厂的天然过滤介质，以及一种新型的、有前景的过滤介质——活性过滤介质。采用多种分析技术对这两种过滤介质的物理化学性质进行了表征，如 X 射线衍射（XRD）、扫描电子显微镜（SEM）、能谱（EDX）、X 射线光电子能谱（XPS）和 Zeta 电位。评价了这些过滤介质对铵和锰的氧化催化活性。XRD 数据表明，活性过滤介质和天然过滤介质均属于水钠锰矿家族。在天然过滤介质的结构中发现了一种新的二氧化锰（MnO）相（PDF#72-1982）。天然过滤介质的 SEM 显微照片显示出蜂窝状结构，而活性过滤介质呈现出板状结构，由堆叠的颗粒组成。这些天然过滤介质的一些微量元素（如钙和镁）水平较低、结晶度较低、Mn(III)含量和晶格氧含量较低，这与其较差的铵和锰催化活性有关。此外，在涂层中发现了一些γ-FeO 和 MnCO，这可能会阻碍铵和锰的催化氧化。本研究对水处理中最常用的过滤介质进行了全面深入的了解，可为实际应用提供理论指导。
