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Indirect assessment of biomass accumulation in a wastewater-based Chlorella vulgaris photobioreactor by pH variation

Algae bloom in coastal waters is partly supported by residual nutrients in treated wastewater (WW) released from coastally located treatment plants. In response, a Chlorella vulgaris-based photobioreactor was recently proposed for lowering nutrient levels in WW prior to release. However, the solutio...

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Autores principales: Otim, Francesca Nyega, Chen, I-Ru, Otim, Ochan
Formato: Online Artículo Texto
Lenguaje:English
Publicado: Nature Publishing Group UK 2021
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8484453/
https://www.ncbi.nlm.nih.gov/pubmed/34593845
http://dx.doi.org/10.1038/s41598-021-98634-0
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author Otim, Francesca Nyega
Chen, I-Ru
Otim, Ochan
author_facet Otim, Francesca Nyega
Chen, I-Ru
Otim, Ochan
author_sort Otim, Francesca Nyega
collection PubMed
description Algae bloom in coastal waters is partly supported by residual nutrients in treated wastewater (WW) released from coastally located treatment plants. In response, a Chlorella vulgaris-based photobioreactor was recently proposed for lowering nutrient levels in WW prior to release. However, the solution requires maintaining biomass accumulation to within a photobioreactor capacity for optimum operation. For high density Chlorella vulgaris suspensions, this is easily done by monitoring turbidity increase, a property directly related to biomass accumulation. For low density suspensions however, direct turbidity measurement would require a cumbersome process of concentrating large volumes of Chlorella vulgaris suspensions. Here, we demonstrate that by measuring pH of the suspensions, turbidity (T) can be estimated indirectly by the following wastewater-dependent expression: pH = aT + pH(0), hence avoiding the need to concentrate large volumes. The term pH(0) is the initial pH of the suspensions and a, a wastewater-dependent constant, can be computed independently from a = − 0.0061*pH(0) + 0.052. In the event %WW is unknown, the following wastewater-independent Gaussian expression can be used to estimate T: pH = 8.71*exp(− [(T − 250)(2)]/[2*1.26E05]). These three equations should offer an avenue for monitoring the turbidity of dilute Chlorella vulgaris suspensions in large, stagnant municipal Chlorella vulgaris-based wastewater treatment system via pH measurements.
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spelling pubmed-84844532021-10-04 Indirect assessment of biomass accumulation in a wastewater-based Chlorella vulgaris photobioreactor by pH variation Otim, Francesca Nyega Chen, I-Ru Otim, Ochan Sci Rep Article Algae bloom in coastal waters is partly supported by residual nutrients in treated wastewater (WW) released from coastally located treatment plants. In response, a Chlorella vulgaris-based photobioreactor was recently proposed for lowering nutrient levels in WW prior to release. However, the solution requires maintaining biomass accumulation to within a photobioreactor capacity for optimum operation. For high density Chlorella vulgaris suspensions, this is easily done by monitoring turbidity increase, a property directly related to biomass accumulation. For low density suspensions however, direct turbidity measurement would require a cumbersome process of concentrating large volumes of Chlorella vulgaris suspensions. Here, we demonstrate that by measuring pH of the suspensions, turbidity (T) can be estimated indirectly by the following wastewater-dependent expression: pH = aT + pH(0), hence avoiding the need to concentrate large volumes. The term pH(0) is the initial pH of the suspensions and a, a wastewater-dependent constant, can be computed independently from a = − 0.0061*pH(0) + 0.052. In the event %WW is unknown, the following wastewater-independent Gaussian expression can be used to estimate T: pH = 8.71*exp(− [(T − 250)(2)]/[2*1.26E05]). These three equations should offer an avenue for monitoring the turbidity of dilute Chlorella vulgaris suspensions in large, stagnant municipal Chlorella vulgaris-based wastewater treatment system via pH measurements. Nature Publishing Group UK 2021-09-30 /pmc/articles/PMC8484453/ /pubmed/34593845 http://dx.doi.org/10.1038/s41598-021-98634-0 Text en © The Author(s) 2021 https://creativecommons.org/licenses/by/4.0/Open Access This article is licensed under a Creative Commons Attribution 4.0 International License, which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons licence, and indicate if changes were made. The images or other third party material in this article are included in the article's Creative Commons licence, unless indicated otherwise in a credit line to the material. If material is not included in the article's Creative Commons licence and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder. To view a copy of this licence, visit http://creativecommons.org/licenses/by/4.0/ (https://creativecommons.org/licenses/by/4.0/) .
spellingShingle Article
Otim, Francesca Nyega
Chen, I-Ru
Otim, Ochan
Indirect assessment of biomass accumulation in a wastewater-based Chlorella vulgaris photobioreactor by pH variation
title Indirect assessment of biomass accumulation in a wastewater-based Chlorella vulgaris photobioreactor by pH variation
title_full Indirect assessment of biomass accumulation in a wastewater-based Chlorella vulgaris photobioreactor by pH variation
title_fullStr Indirect assessment of biomass accumulation in a wastewater-based Chlorella vulgaris photobioreactor by pH variation
title_full_unstemmed Indirect assessment of biomass accumulation in a wastewater-based Chlorella vulgaris photobioreactor by pH variation
title_short Indirect assessment of biomass accumulation in a wastewater-based Chlorella vulgaris photobioreactor by pH variation
title_sort indirect assessment of biomass accumulation in a wastewater-based chlorella vulgaris photobioreactor by ph variation
topic Article
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8484453/
https://www.ncbi.nlm.nih.gov/pubmed/34593845
http://dx.doi.org/10.1038/s41598-021-98634-0
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