Breakthrough of cyanobacteria in bank filtration
Author(s)
Pazouki, Pirooz
Prevost, Michele
McQuaid, Natasha
Barbeau, Benoit
de Boutray, Marie-Laure
Zamyadi, Arash
Dorner, Sarah
Year published
2016
Metadata
Show full item recordAbstract
The removal of cyanobacteria cells in well water following bank filtration was investigated from a source water consisting of two artificial lakes (A and B). Phycocyanin probes used to monitor cyanobacteria in the source and in filtered well water showed an increase of fluorescence values demonstrating a progressive seasonal growth of cyanobacteria in the source water that were correlated with cyanobacterial biovolumes from taxonomic counts (r = 0.59, p < 0.00001). A strong correlation was observed between the cyanobacterial concentrations in the lake water and in the well water as measured by the phycocyanin probe (p < 0.001, ...
View more >The removal of cyanobacteria cells in well water following bank filtration was investigated from a source water consisting of two artificial lakes (A and B). Phycocyanin probes used to monitor cyanobacteria in the source and in filtered well water showed an increase of fluorescence values demonstrating a progressive seasonal growth of cyanobacteria in the source water that were correlated with cyanobacterial biovolumes from taxonomic counts (r = 0.59, p < 0.00001). A strong correlation was observed between the cyanobacterial concentrations in the lake water and in the well water as measured by the phycocyanin probe (p < 0.001, 0.73 ≤ r(2) ≤ 0.94). Log removals from bank filtration estimated from taxonomic counts ranged from 0.96 ± (0.5) and varied according to the species of cyanobacteria. Of cyanobacteria that passed through bank filtration, smaller cells were significantly more frequent in well water samples (p < 0.05) than larger cells. Travel times from the lakes to the wells were estimated as 2 days for Lake B and 10 days for Lake A. Cyanobacterial species in the wells were most closely related to species found in Lake B. Thus, a travel time of less than 1 week permitted the breakthrough of cyanobacteria to wells. Winter samples demonstrated that cyanobacteria accumulate within bank filters, leading to continued passage of cells beyond the bloom season. Although no concentrations of total microcystin-LR were above detection limits in filtered well water, there is concern that cyanobacterial cells that reach the wells have the potential to contain intracellular toxins.
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View more >The removal of cyanobacteria cells in well water following bank filtration was investigated from a source water consisting of two artificial lakes (A and B). Phycocyanin probes used to monitor cyanobacteria in the source and in filtered well water showed an increase of fluorescence values demonstrating a progressive seasonal growth of cyanobacteria in the source water that were correlated with cyanobacterial biovolumes from taxonomic counts (r = 0.59, p < 0.00001). A strong correlation was observed between the cyanobacterial concentrations in the lake water and in the well water as measured by the phycocyanin probe (p < 0.001, 0.73 ≤ r(2) ≤ 0.94). Log removals from bank filtration estimated from taxonomic counts ranged from 0.96 ± (0.5) and varied according to the species of cyanobacteria. Of cyanobacteria that passed through bank filtration, smaller cells were significantly more frequent in well water samples (p < 0.05) than larger cells. Travel times from the lakes to the wells were estimated as 2 days for Lake B and 10 days for Lake A. Cyanobacterial species in the wells were most closely related to species found in Lake B. Thus, a travel time of less than 1 week permitted the breakthrough of cyanobacteria to wells. Winter samples demonstrated that cyanobacteria accumulate within bank filters, leading to continued passage of cells beyond the bloom season. Although no concentrations of total microcystin-LR were above detection limits in filtered well water, there is concern that cyanobacterial cells that reach the wells have the potential to contain intracellular toxins.
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Journal Title
Water Research
Volume
102
Subject
Environmental engineering
Science & Technology
Life Sciences & Biomedicine
Physical Sciences
Engineering, Environmental