Enhanced real-time cyanobacterial fluorescence monitoring through chlorophyll-a interference compensation corrections

F Choo; A Zamyadi; R M Stuetz; G Newcombe; K Newton; R K Henderson

doi:10.1016/j.watres.2018.10.034

Enhanced real-time cyanobacterial fluorescence monitoring through chlorophyll-a interference compensation corrections

Water Res. 2019 Jan 1:148:86-96. doi: 10.1016/j.watres.2018.10.034. Epub 2018 Oct 15.

Authors

F Choo¹, A Zamyadi², R M Stuetz³, G Newcombe⁴, K Newton⁴, R K Henderson⁵

Affiliations

¹ BioMASS Lab, School of Chemical Engineering, The University of New South Wales, Sydney, New South Wales, 2052, Australia.
² BioMASS Lab, School of Chemical Engineering, The University of New South Wales, Sydney, New South Wales, 2052, Australia; Département des génies civil, géologique et des mines, École Polytechnique de Montréal, Montréal, Québec, H3T 1J4, Canada; UNSW Water Research Centre, School of Civil and Environmental Engineering, The University of New South Wales, Sydney, New South Wales, 2052, Australia.
³ UNSW Water Research Centre, School of Civil and Environmental Engineering, The University of New South Wales, Sydney, New South Wales, 2052, Australia.
⁴ Australian Water Quality Centre, SA Water Corporation, Adelaide, South Australia, 5000, Australia.
⁵ BioMASS Lab, School of Chemical Engineering, The University of New South Wales, Sydney, New South Wales, 2052, Australia. Electronic address: r.henderson@unsw.edu.au.

PMID: 30352324
DOI: 10.1016/j.watres.2018.10.034

Abstract

In situ fluorometers can be used as a real-time cyanobacteria detection tool to maintain safe drinking and recreational water standards. However, previous studies into fluorometers have established issues arising mainly from measurement inaccuracies due to green algae interference. Therefore, this study focusses on developing correction factors from a systematic study on the impact of green algae as an interference source. This study brings a novel technique where the chlorophyll-a (Chl-a) and phycocyanin measurements are used to correct the fluorometer output for interference bias; four fluorometers were tested against three key cyanobacterial species and the relationship between phycocyanin output, green algae and cyanobacteria concentrations were investigated. Good correlation (R² > 0.9, p-value < 0.05) was found between the fluorometer phycocyanin output and increasing green algae concentration. The optimal correction method was selected for each of the fluorometer and cyanobacteria species pairs by validating against data from the investigation of green algae as an interference source. The correction factors determined in this study reduced the measurement error for almost all the fluorometers and species tested by 21%-99% depending on the species and fluorometer, compared to previous published correction factors in which the measurement error was reduced by approximately 11%-81%. Field validation of the correction factors showed reduction in fluorometer measurement error at sites in which cyanobacterial blooms were dominated by a single species.

Keywords: Algae and cyanobacteria; In situ probe; Phycocyanin; Source management.

Publication types

Research Support, Non-U.S. Gov't

MeSH terms

Chlorophyll
Chlorophyll A*
Cyanobacteria*
Environmental Monitoring
Fluorescence
Phycocyanin

Substances

Phycocyanin
Chlorophyll
Chlorophyll A