Potential Impacts on Treated Water Quality of Recycling Dewatered Sludge Supernatant during Harmful Cyanobacterial Blooms
Cyanobacterial blooms and the associated release of cyanotoxins pose problems for many conventional water treatment plants due to their limited removal by typical unit operations. In this study, a conventional water treatment process consisting of coagulation, flocculation, sedimentation, filtration...
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| Format: | Article |
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MDPI AG
2021-01-01
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| Series: | Toxins |
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| Online Access: | https://www.mdpi.com/2072-6651/13/2/99 |
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| author | Kanarat Pinkanjananavee Swee J. Teh Tomofumi Kurobe Chelsea H. Lam Franklin Tran Thomas M. Young |
| author_facet | Kanarat Pinkanjananavee Swee J. Teh Tomofumi Kurobe Chelsea H. Lam Franklin Tran Thomas M. Young |
| author_sort | Kanarat Pinkanjananavee |
| collection | DOAJ |
| description | Cyanobacterial blooms and the associated release of cyanotoxins pose problems for many conventional water treatment plants due to their limited removal by typical unit operations. In this study, a conventional water treatment process consisting of coagulation, flocculation, sedimentation, filtration, and sludge dewatering was assessed in lab-scale experiments to measure the removal of microcystin-LR and <i>Microcystis aeruginosa</i> cells using liquid chromatography with mass spectrometer (LC-MS) and a hemacytometer, respectively. The overall goal was to determine the effect of recycling cyanotoxin-laden dewatered sludge supernatant on treated water quality. The lab-scale experimental system was able to maintain the effluent water quality below relevant the United States Environmental Protection Agency (US EPA) and World Health Organisation (WHO) standards for every parameter analyzed at influent concentrations of <i>M. aeruginosa</i> above 10<sup>6</sup> cells/mL. However, substantial increases of 0.171 NTU (Nephelometric Turbidity Unit), 7 × 10<sup>4</sup> cells/L, and 0.26 µg/L in turbidity, cyanobacteria cell counts, and microcystin-LR concentration were observed at the time of dewatered supernatant injection. Microcystin-LR concentrations of 1.55 µg/L and 0.25 µg/L were still observed in the dewatering process over 24 and 48 h, respectively, after the initial addition of <i>M.</i><i>aeruginosa</i> cells, suggesting the possibility that a single cyanobacterial bloom may affect the filtered water quality long after the bloom has dissipated when sludge supernatant recycling is practiced. |
| first_indexed | 2024-03-09T03:18:00Z |
| format | Article |
| id | doaj.art-799544be491e49a28eb945e519dcef8a |
| institution | Directory Open Access Journal |
| issn | 2072-6651 |
| language | English |
| last_indexed | 2024-03-09T03:18:00Z |
| publishDate | 2021-01-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Toxins |
| spelling | doaj.art-799544be491e49a28eb945e519dcef8a2023-12-03T15:14:47ZengMDPI AGToxins2072-66512021-01-011329910.3390/toxins13020099Potential Impacts on Treated Water Quality of Recycling Dewatered Sludge Supernatant during Harmful Cyanobacterial BloomsKanarat Pinkanjananavee0Swee J. Teh1Tomofumi Kurobe2Chelsea H. Lam3Franklin Tran4Thomas M. Young5Department of Civil & Environmental Engineering, University of California Davis, Davis, CA 95616, USADepartment of Anatomy, Physiology, and Cell Biology, School of Veterinary Medicine, University of California Davis, Davis, CA 95616, USADepartment of Anatomy, Physiology, and Cell Biology, School of Veterinary Medicine, University of California Davis, Davis, CA 95616, USADepartment of Anatomy, Physiology, and Cell Biology, School of Veterinary Medicine, University of California Davis, Davis, CA 95616, USADepartment of Anatomy, Physiology, and Cell Biology, School of Veterinary Medicine, University of California Davis, Davis, CA 95616, USADepartment of Civil & Environmental Engineering, University of California Davis, Davis, CA 95616, USACyanobacterial blooms and the associated release of cyanotoxins pose problems for many conventional water treatment plants due to their limited removal by typical unit operations. In this study, a conventional water treatment process consisting of coagulation, flocculation, sedimentation, filtration, and sludge dewatering was assessed in lab-scale experiments to measure the removal of microcystin-LR and <i>Microcystis aeruginosa</i> cells using liquid chromatography with mass spectrometer (LC-MS) and a hemacytometer, respectively. The overall goal was to determine the effect of recycling cyanotoxin-laden dewatered sludge supernatant on treated water quality. The lab-scale experimental system was able to maintain the effluent water quality below relevant the United States Environmental Protection Agency (US EPA) and World Health Organisation (WHO) standards for every parameter analyzed at influent concentrations of <i>M. aeruginosa</i> above 10<sup>6</sup> cells/mL. However, substantial increases of 0.171 NTU (Nephelometric Turbidity Unit), 7 × 10<sup>4</sup> cells/L, and 0.26 µg/L in turbidity, cyanobacteria cell counts, and microcystin-LR concentration were observed at the time of dewatered supernatant injection. Microcystin-LR concentrations of 1.55 µg/L and 0.25 µg/L were still observed in the dewatering process over 24 and 48 h, respectively, after the initial addition of <i>M.</i><i>aeruginosa</i> cells, suggesting the possibility that a single cyanobacterial bloom may affect the filtered water quality long after the bloom has dissipated when sludge supernatant recycling is practiced.https://www.mdpi.com/2072-6651/13/2/99harmful cyanobacteriacyanotoxinsconventional water treatment |
| spellingShingle | Kanarat Pinkanjananavee Swee J. Teh Tomofumi Kurobe Chelsea H. Lam Franklin Tran Thomas M. Young Potential Impacts on Treated Water Quality of Recycling Dewatered Sludge Supernatant during Harmful Cyanobacterial Blooms Toxins harmful cyanobacteria cyanotoxins conventional water treatment |
| title | Potential Impacts on Treated Water Quality of Recycling Dewatered Sludge Supernatant during Harmful Cyanobacterial Blooms |
| title_full | Potential Impacts on Treated Water Quality of Recycling Dewatered Sludge Supernatant during Harmful Cyanobacterial Blooms |
| title_fullStr | Potential Impacts on Treated Water Quality of Recycling Dewatered Sludge Supernatant during Harmful Cyanobacterial Blooms |
| title_full_unstemmed | Potential Impacts on Treated Water Quality of Recycling Dewatered Sludge Supernatant during Harmful Cyanobacterial Blooms |
| title_short | Potential Impacts on Treated Water Quality of Recycling Dewatered Sludge Supernatant during Harmful Cyanobacterial Blooms |
| title_sort | potential impacts on treated water quality of recycling dewatered sludge supernatant during harmful cyanobacterial blooms |
| topic | harmful cyanobacteria cyanotoxins conventional water treatment |
| url | https://www.mdpi.com/2072-6651/13/2/99 |
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