Detection of chlorophyll fluorescence as a rapid alert of eutrophic water. Issue 3 (15th November 2021)

• Record Type: Journal Article
• Authors: Chen, Chih-Kuei; Chen, Ying-Chu
• Is Part Of: Water Supply. Volume 22:Issue 3(2022)
• Page Start: 3508
• Page End: 3518
• Publication Date: 2021-11-15
• Subjects: chlorophyll -- chromaticity -- cyanobacteria -- eutrophication -- fluorescence
• DOI: 10.2166/ws.2021.388
• Languages: English
• ISSNs: 1606-9749

Abstract

Abstract: An in-situ detection of chlorophyll fluorescence was used in an innovative manner to detect eutrophic water, and the results were compared with the Carlson's Trophic State Index (CTSI) indicators. Eutrophication was due to climate warming and anthropogenic activities. The turbidity and chromaticity showed a strong linear relationship (R 2 = 0.85) of the Bi Lake in Taipei city. Both the swimming area and the bridge are popular with the general public and had the worst turbidity (35.80–44.00 NTU) and chromaticity (495.37–552.27 Pt). The CTSI had a stronger linear relationship with the phycocyanin (PC) concentration (R 2 = 0.605) than with any other three CTSI factors like chlorophyll-a concentration, total phosphorus (TP) concentration, and transparency. The TP pollution had a potential to cause an increase in PC concentration found in this study (R 2 = 0.86). The absorbances of the water samples represented that the environment is PC (cyanobacteria) dominant in winter. The PC concentration in Bi Lake ranged from 75.55 to 80.24 μg/L and was higher with lower water temperature. Measurement of in-situ chlorophyll fluorescence is similar to lab-scale spectrophotometer (R 2 >0.92). The real-time detection of PC concentration could be the basis of a rapid alert system for biological threats to waters. HIGHLIGHTS: Total phosphorus had a stronger linear relationship with the phycocyanin concentration. Phycocyanin concentration had higher correlation than a single CTSI indicator. The environment is cyanobacteria dominant in winter but changes to chlorophyll-a in summer. Measurement of in-situ chlorophyll fluorescence is verified by lab-scale spectrophotometer.