SCI和EI收录∣中国化工学会会刊

中国化学工程学报 ›› 2023, Vol. 57 ›› Issue (5): 10-16.DOI: 10.1016/j.cjche.2022.06.032

• Full Length Article • 上一篇    下一篇

Effects of heavy metal ions Cu2+/Pb2+/Zn2+ on kinetic rate constants of struvite crystallization

Guangyuan Chen1, Tong Zhou1, Meng Zhang1, Zhongxiang Ding1, Zhikun Zhou1, Yuanhui Ji2, Haiying Tang3, Changsong Wang1   

  1. 1. State Key Laboratory of Materials-Oriented Chemical Engineering, Nanjing Tech University, Nanjing 211816, China;
    2. Jiangsu Province Hi-Tech Key Laboratory for Biomedical Research, School of Chemistry and Chemical Engineering, Southeast University, Nanjing 211189, China;
    3. Qinghai Salt Lake Yuantong Potash Fertilizer Co., Ltd., Golmud 816000, China
  • 收稿日期:2022-03-29 修回日期:2022-06-12 出版日期:2023-05-28 发布日期:2023-07-08
  • 通讯作者: Changsong Wang,E-mail:wcs@njtech.edu.cn
  • 基金资助:
    This research receives financial support from the National Natural Science Foundation of China (21838004), Priority Academic Program Development of Jiangsu Higher Education Institutions (PPZY2015A044), and Top-notch Academic Programs Project of Jiangsu Higher Education Institution (TAPP).

Effects of heavy metal ions Cu2+/Pb2+/Zn2+ on kinetic rate constants of struvite crystallization

Guangyuan Chen1, Tong Zhou1, Meng Zhang1, Zhongxiang Ding1, Zhikun Zhou1, Yuanhui Ji2, Haiying Tang3, Changsong Wang1   

  1. 1. State Key Laboratory of Materials-Oriented Chemical Engineering, Nanjing Tech University, Nanjing 211816, China;
    2. Jiangsu Province Hi-Tech Key Laboratory for Biomedical Research, School of Chemistry and Chemical Engineering, Southeast University, Nanjing 211189, China;
    3. Qinghai Salt Lake Yuantong Potash Fertilizer Co., Ltd., Golmud 816000, China
  • Received:2022-03-29 Revised:2022-06-12 Online:2023-05-28 Published:2023-07-08
  • Contact: Changsong Wang,E-mail:wcs@njtech.edu.cn
  • Supported by:
    This research receives financial support from the National Natural Science Foundation of China (21838004), Priority Academic Program Development of Jiangsu Higher Education Institutions (PPZY2015A044), and Top-notch Academic Programs Project of Jiangsu Higher Education Institution (TAPP).

摘要: Struvite (MAP) crystallization technology is widely used to treat ammonia nitrogen in waste effluents of its simple operation and good removal efficiency. However, the presence of heavy metal ions in the waste effluents causes problems such as slow crystallization rate and small crystal size, limiting the recovery rate and economic value of the MAP. The present study was conducted to investigate the effects of concentrations of three heavy metal ions (Cu2+, Zn2+, and Pb2+) on the crystal morphology, crystal size, average growth rate, and crystallization kinetics of MAP. A relationship was established between the kinetic rate constant Kt calculated by the chemical gradient model and the concentrations of heavy metal ions. The results showed that low concentrations of heavy metal ions in the solution created pits on the MAP surface, and high level of heavy metal ions generated flocs on the MAP surface, which were composed of metal hydroxides, thus inhibiting crystal growth. The crystal size, average growth rate, MAP crystallization rate, and kinetic rate constant Kt decreased with the increase in heavy metal ion concentration. Moreover, the Kt demonstrated a linear relationship with the heavy metal concentration ln(C/C*), which provided a reference for the optimization of the MAP crystallization process in the presence of heavy metal ions.

关键词: Struvite, Crystallization, Heavy metal ions, Kinetics, Kinetic modeling, Kinetic rate constant

Abstract: Struvite (MAP) crystallization technology is widely used to treat ammonia nitrogen in waste effluents of its simple operation and good removal efficiency. However, the presence of heavy metal ions in the waste effluents causes problems such as slow crystallization rate and small crystal size, limiting the recovery rate and economic value of the MAP. The present study was conducted to investigate the effects of concentrations of three heavy metal ions (Cu2+, Zn2+, and Pb2+) on the crystal morphology, crystal size, average growth rate, and crystallization kinetics of MAP. A relationship was established between the kinetic rate constant Kt calculated by the chemical gradient model and the concentrations of heavy metal ions. The results showed that low concentrations of heavy metal ions in the solution created pits on the MAP surface, and high level of heavy metal ions generated flocs on the MAP surface, which were composed of metal hydroxides, thus inhibiting crystal growth. The crystal size, average growth rate, MAP crystallization rate, and kinetic rate constant Kt decreased with the increase in heavy metal ion concentration. Moreover, the Kt demonstrated a linear relationship with the heavy metal concentration ln(C/C*), which provided a reference for the optimization of the MAP crystallization process in the presence of heavy metal ions.

Key words: Struvite, Crystallization, Heavy metal ions, Kinetics, Kinetic modeling, Kinetic rate constant