Poster Presentation SETAC Asia-Pacific Virtual Conference 2022

CoFe bimetal oxides with controllable structure and active site for phosphate removal (#108)

Xiaoxu Jing 1 2 , Qile Fang* 2 3 , Yungui Li* 1 4
  1. Sichuan Provincial Sci-Tech Cooperation Base of Low-cost Wastewater Treatment Technology, Department of Environmental Engineering, Southwest University of Science and Technology, Mianyang, 621010, PR China
  2. Advanced Institute of Natural Sciences, Beijing Normal University, Zhuhai, 519087, PR China
  3. Chongqing Feiyang Measurement and Control Technology Research Institute Co., Ltd., Chongqing, 402760, PR China
  4. NHC Key Laboratory of Nuclear Technology Medical Transformation, Mianyang Central Hospital, Mianyang, 621010, PR China

The discharge of agricultural wastewater, aquaculture wastewater and domestic sewage leads to the enrichment of phosphorus elements and the eutrophication of rural water bodies. Thus, phosphorus wastewater treatment technology has always been concerned. In recent years, adsorption method has become the mainstream of phosphorus removal due to its advantages of economy, high efficiency and environmental protection. Here, we provide a preparation method to obtain CoFe bimetal oxides with different structures by using Prussian blue analogues (PBAs) as designable precursors, and further explored the removal of phosphate. In this work, two CoFoPBA precursors with different morphologies were prepared by a rate-controlled coordination strategy, and then CoFe oxides inheriting the precursor morphologies were obtained via mesothermal calcination. Compared with the fast rate coordination product CoFeF, the product CoFeS with truncated microcube structure obtained by slow rate coordination contains less coordinated water and Fe3+ in the framework, however the product CoFeST300 after mesothermal oxidation has more mesopores and Fe3+. More mesopores allowed it to exhibit a higher initial diffusion rate during phosphate adsorption. Meanwhile, Fe3+ as the efficient adsorption sites for ligand exchange, resulting in higher adsorption capacity and affinity of CoFeST300 for phosphate. Therefore, structural design is an effective method to obtain ideal metal oxides for phosphorus removing. In addition, CoFeST300 is renewable and has high selectivity for phosphate removal. More importantly, in the multiple continuous treatment of actual sewage, the efflfluent concentrations of all wastewater after CoFeST300 treatment was dropped below 0.5mgP/L, which confirms that CoFeST300 has excellent potential in practical application of phosphorus removal.