Journal of Ecology and Rural Environment ›› 2022, Vol. 38 ›› Issue (4): 521-530.doi: 10.19741/j.issn.1673-4831.2021.0280

Previous Articles     Next Articles

Fluorescence Characteristics of DOC for Landscape Water in Beijing and Its Complexing Characteristics with Copper and Lead

XU Xin-yao1, PU Xiao1, GAO Jing1, DONG Xue1, ZHANG Yu-hu1, HU Yan-jia1, MENG Shao-kang1, WANG Jian2   

  1. 1. School of Resources Environment & Tourism, Capital Normal University, Beijing 100048, China;
    2. Safety and Environmental Management Headquarters of Tsingtao Brewery Co. Ltd., Qingdao 266071, China
  • Received:2021-05-07 Online:2022-04-22 Published:2022-04-22

Abstract: The landscape water in four parks in Beijing (Nanhaizi Park, Yuanmingyuan, Taoranting Park, and Longtan Park) was selected as the research objects to analyze the fluorescence composition and molecular weight distribution characteristics of the water DOC. Fluorescence quenching titration experiments were performed on DOC with different molecular weights and Cu2+, Pb2+, for determining the contents of complexed heavy metals, the fluorescent components involved in the complexation, and the complexing parameters and for showing the complexing characteristics of different heavy metal ions with DOC. The results show that three fluorescent components were identified in the DOC of Beijing's landscape water bodies, among which C1 and C2 representing humus-like substances, and C3 representing protein-like tryptophan substances. After grading the molecular weight of DOC, it was found that two fluorescent components were identified in the classified DOC, including the humus-like component C1 and the protein-like tryptophan component C2. After the fluorescence quenching titration experiment, the contents of heavy metals in the complex state formed by <1 kDa DOC was the highest. Moreover, the complex stability constant of the two heavy metals complexed with <1 kDa DOC was the largest. The concentration of DOC-Pb (16.91-99.15 μmol·L-1) was greater than DOC-Cu (12.42-95.99 μmol·L-1). However, the quenching degree and complex stability constant of Cu2+ and the two fluorescent components were stronger than that of Pb2+. The quenching effect of Cu2+ on component C1 was stronger than that of C2, indicating that Cu2+ was more inclined to complex with humus-like components. However, Pb2+ had no obvious tendency to complex with different components. The results provide guidance for the water quality maintenance and potential pollution control of landscape water in Beijing.

Key words: landscape water, dissolved organic carbon, heavy metals, fluorescence characteristics, complexation

CLC Number: