Song Wei, Dong Jiahao, Chen Weiyun, Lin Dachao, Du Xing, Nie Jinxu, Wang Zhihong, Tian Jiayu
School of Civil and Transportation Engineering, Guangdong University of Technology, Guangzhou, 510006, PR China.
School of Civil and Transportation Engineering, Guangdong University of Technology, Guangzhou, 510006, PR China.
Environ Pollut. 2024 Dec 15;363(Pt 1):125046. doi: 10.1016/j.envpol.2024.125046. Epub 2024 Sep 30.
High concentrations of manganese ion (Mn) and ammonia nitrogen (NH-N) in groundwater are indicative of a critical environmental issue that necessitates immediate attention. The gravity-driven ceramic membrane (GDCM) technology has shown great potential for groundwater treatment in rural communities, owing to its low energy demand and user-friendly operation. Active manganese oxide (MnO) is extensively used for the concurrent removal of Mn and NH-N, leveraging its large specific surface area and abundant adsorption sites. Our research group has developed a GDCM-MnO coupled system to address this challenge. However, membrane fouling, manifested as a reduction in flux or an increase in transmembrane pressure, has been a significant barrier to its widespread adoption. To address this challenge, we have implemented a continuous aeration system in conjunction with GDCM to fluidize birnessite to achieve the higher membrane flux, which has also proven effective in mitigating fouling while maintaining high water purification performance. Over a period of 100 days or more, the high membrane flux in the high-flux GDCM system (HF-GDCM) enhanced with aerated fluidized birnessite has been consistently maintained at approximately 34 L/(m·h) at a water head of 1 m. Moreover, the HF-GDCM system efficiently removed manganese and NH-N from groundwater under a hydraulic retention time (HRT) of less than 2.5 h, while also improving membrane permeability. The involvement of manganese oxidizing bacteria (MnOB) and ammonium-oxidizing bacteria (AOB) of Hypomicrobium and Nocardioides in the removal processes within the HF-GDCM system was confirmed. Additionally, XPS analysis confirmed the predominant oxidation state of MnO to be Mn(III). The MnO, deposited on powdered activated carbon (PAC) particles in a flower-like configuration, progressively formed a birnessite-like functional layer as the manganese ion content increased over time. Consequently, the HF-GDCM coupled with aerated fluidized birnessite is deemed suitable for water purification in small-scale rural or reservoir settings.
地下水中高浓度的锰离子（Mn）和氨氮（NH-N）表明存在一个亟需立即关注的严峻环境问题。重力驱动陶瓷膜（GDCM）技术因其低能量需求和操作简便，在农村社区的地下水处理中显示出巨大潜力。活性氧化锰（MnO）因其大比表面积和丰富的吸附位点，被广泛用于同时去除锰和氨氮。我们的研究团队开发了一种GDCM-MnO耦合系统来应对这一挑战。然而，膜污染表现为通量降低或跨膜压力增加，一直是其广泛应用的重大障碍。为应对这一挑战，我们结合GDCM实施了连续曝气系统，以使水钠锰矿流化，从而实现更高的膜通量，这也被证明在减轻污染的同时能保持高水净化性能方面是有效的。在100天或更长时间内，曝气流化水钠锰矿的高通量GDCM系统（HF-GDCM）在1米水头下的高膜通量一直稳定保持在约34升/（平方米·小时）。此外，HF-GDCM系统在水力停留时间（HRT）小于2.5小时的情况下，能有效去除地下水中的锰和氨氮，同时还提高了膜的渗透性。证实了微小杆菌属和诺卡氏菌属的锰氧化细菌（MnOB）和氨氧化细菌（AOB）参与了HF-GDCM系统内的去除过程。此外，X射线光电子能谱分析证实MnO的主要氧化态为Mn(III)。以花状结构沉积在粉末活性炭（PAC）颗粒上的MnO随着锰离子含量随时间增加而逐渐形成类似水钠锰矿的功能层。因此，结合曝气流化水钠锰矿的HF-GDCM被认为适用于小规模农村或水库环境的水净化。
