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Investigation of pollutants accumulation in the submerged zone for pyrite-based bioretention facilities under continuous rainfall events.

Authors :
Wang, Xinyue
Ma, Haiyuan
Huang, Cong
Xu, Zheng
Wang, Yin
Yang, Yan
Xiao, Huan
Zhi, Yue
Chen, Lei
Chai, Hongxiang
Source :
Journal of Environmental Management. Jul2024, Vol. 364, pN.PAG-N.PAG. 1p.
Publication Year :
2024

Abstract

Submerged zone in bioretention facilities for stormwater treatment has been approved to be an effective structure amendment to improve denitrification capability. However, the role and influence of water quality changes in the submerged zone under natural continuous random rainfall patterns are still not clear, especially when the rainfall is less than the pore water in the submerged zone. In this study, continuous rainfall events with different rainfall volume (light rain-light rain-heavy rain) were designed in a lab-scale woodchip mulched pyrite bioretention facility to test the effects of rainfall pattern. The results exhibited that light rain events significantly affected the pollutant removal performance of bioretention for the next rainfall. Different effects were observed during the long-term operation. In the 5th month, light rain reduced the ammonia removal efficiency of subsequent rainstorm events by 8.70%, while in the 12th month, when nitrate leakage occurred, light rain led to a 40.24% reduction in the next heavy rain event's nitrate removal efficiency. Additionally, light rain would also affect the concentration of by-products in the next rainfall. Following a light rain, the concentration of sulfate in the subsequent light rainfall can increase by 24.4 mg/L, and by 11.92 mg/L in a heavy rain. The water quality in the submerged zone and media characteristics analysis suggested that nitrogen conversion capacity of the substrate and microbes, such as Nitrospira (2.86%) and Thiobacillus (35.71%), as well as the in-situ accumulation of pollutants under light rain played important roles. This study clarifies the relationship between successive rainfall events and provides a more comprehensive understanding of bioretention facilities. This is beneficial for field study of bioretention facilities in the face of complex rainfall events. [Display omitted] • A novel rainfall pattern was proposed to evaluate the efficiency of bioretention. • Light rain significantly impacts the performance of the next heavy rainfall. • Light rain leads to nitrate and sulfate accumulation in the submerged zone. • Microorganism is the main factor of ammonia accumulation in submerged zone. • 5. Thiobacillus and Pseudomonas are the dominant bacteria in the submerged zone. [ABSTRACT FROM AUTHOR]

Details

Language :
English
ISSN :
03014797
Volume :
364
Database :
Academic Search Index
Journal :
Journal of Environmental Management
Publication Type :
Academic Journal
Accession number :
177992198
Full Text :
https://doi.org/10.1016/j.jenvman.2024.121448