Effects of shading & calcium peroxide suspension on landscape water quality and CH4 and N2O production

• Published in: Journal of water process engineering Vol. 65; p. 105813
• Main Authors: Fu, Tian-Tian, Wang, Yi, Zhao, Hui-Ying, Liang, Zhen-Hao, Zhang, Kai, Wang, Yue-Ning, Ouyang, Hui-Long, Yin, Jia-Ni, Liu, Yong-Qiang
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 01.08.2024
• Subjects: Calcium peroxide suspension; Eutrophication control; Shading; Strong greenhouse gas reduction; Urban landscape water; Eutrophication control; Shading; Urban landscape water; Calcium peroxide suspension; Strong greenhouse gas reduction
• ISSN: 2214-7144; 2214-7144
• DOI: 10.1016/j.jwpe.2024.105813

Landscape water plays an important role in regulating the urban heat island effect, but its eutrophication can intensity greenhouse gas (GHGs) emissions. Thus, effective strategies are needed to manage water quality and GHGs simultaneously. This study aims to mitigate eutrophication and GHGs production of landscape water during summer through shading or calcium peroxide (CP) suspension. Results demonstrate that 60 % shading, 1.0 g CP/L suspension, and their combination could effectively purify landscape water and lower GHGs emissions. By reducing the concentration of nitrogen, phosphorus, and organic matter, and controlling algal density and Chl-a level, the study successfully lowered the production of CH4 and N2O. Compared to the control, TN, TP and COD concentrations decreased by 43.21 %, 71.85 %, and 68.04 %, respectively, while algal density and Chl-a decreased by 74.84 % and 77.08 % under the usage of combined shading and CP suspension. Furthermore, the accumulation of CH4 and N2O decreased by 43.84 % and 15.18 % on average, potentially due to the reduced abundance of Methanomassiliicoccus and LD29 under the combination condition. This study proposed an innovative approach to actively manage GHGs in landscape water bodies while improving water quality, which is a potential strategy to alleviate urban heat island effects. [Display omitted] •Shading&CP suspension effectively controls nutrients and algae in water bodies.•Shading and CP suspension jointly reduced 43.84 % CH4 and 15.18 % N2O in water.•Shading&CP suspension, alone or combined, reduces GWP mainly by controlling CH4.•High accumulation of GHGs may be linked to the high LD29 nitrogenase activity.