Effect of pH Change on the Microalgae-Based Biogas Upgrading Process
Open accessAbstract
An alternative way to remove CO2 from biogas is the use of photosynthetic microorganisms, such as microalgae. This can be achieved by the operation of an open photobioreactor, connected with a mass transfer column, such as a counterflow column. This technology provides up-graded biogas with high quality. The microalgal uptake of CO2 from the biogas in counterflow columns generates pH changes in microalgae culture. To clarify the potential effect of these dynamic pH conditions in the culture, the effect of pH change on the photosynthetic activity and PSII quantum yield was studied for microalgae Chlorella sorokiniana. Thus, assays were carried out, where the pH drop reported in the counterflow columns was replicated in batch microalgae culture through HCl addition and CO2 injection, moving the culture pH from 7.0 to 5.0 and from 7.0 to 5.8, respectively. Moreover, the effect of light/darkness on photosynthetic activity was tested when the pH decreased. The results obtained in this research showed that the photosynthetic activity decreased for the light conditions when the pH was shifted by HCl addition and CO2 injection. Despite this, the value of the PSII quantum yield remained at 0.6–0.7, which means that the microalgae culture did not suffer a negative effect on the photosynthetic system of cells because a high value of PSII efficiency remained. In the same way, the results indicated that when the pH change was corrected, the photosynthetic activity recovered. Moreover, the apparent affinity constant for dissolved inorganic carbon (KDIC) was 0.9 µM at pH 5 and 112.0 µM at pH 7, which suggests that the preferred carbon source for C.sorokniana is CO2. Finally, all the results obtained indicated that the pH drop in the counter-flow column for biogas upgrading did not cause permanent damage to the photosynthetic system, and the decrease in the photosynthetic activity as a result of the pH drop can be recovered when the pH is corrected.
The claims and statistics of this paper haven’t been checked yet.
Run the check — free, no account needed. It reads the open-access text and checks the sources it cites.
Integrity signals
Registry
Cites
Statistics
Claims the paper makes
The claims and statistics of this paper haven’t been checked yet.
Run the check — free, no account needed. It reads the open-access text and checks the sources it cites.
Claims other papers make about this one
Each is checked against this paper’s own text: does it say what the citing paper says it does?
In intensive photoautotrophic microalgae cultivation carried out at light intensities above the compensation point, the pH of the culture tends to increase due to efficient uptake of CO2 and HCO3- and assimilation of nitrates.
“In intensive photoautotrophic microalgae cultivation carried out at light intensities above the compensation point-where the photosynthetic rate equals the respiration ratethe pH of the culture tends to increase. This occurs because during active microalgae growth there is an efficient uptake of CO2 and HCO 3 -from the culture medium and an assimilation of nitrates.”
From Multi-Sensing Monitoring of the Microalgae Biomass Cultivation Systems for Biofuels and Added Value Products Synthesis—Challenges and Opportunities (2025) · cites this paper as [176]
The Introduction (page not available) says pH is expected to increase in the photobioreactor because of photosynthetic activity, and the Results report a pH increase after CO2 injection stopped, partly due to carbon fixation. The paper also says microalgae can use bicarbonate as a carbon source. It does not establish the claim's above-compensation-point condition or attribute the pH increase to nitrate assimilation. (LLM, conf=0.86)
Experimental — accuracy not yet measuredThe acceptable pH range for most microalgae species is between 7 and 9, with a typical optimum at 8.2-8.7.
“The acceptable pH range for most microalgae species is between 7 and 9, with a typical optimum at 8.2-8.7.”
From Multi-Sensing Monitoring of the Microalgae Biomass Cultivation Systems for Biofuels and Added Value Products Synthesis—Challenges and Opportunities (2025) · cites this paper as [176]
An increase in CO2 concentration leads to a higher H+ ion concentration and lowers the pH value, while a decrease in CO2 concentration reduces the H+ concentration and increases the pH value.
“An increase in the CO2 concentration leads to a higher H + ion concentration and lowers the pH value (acidification). Conversely, a decrease in the CO2 concentration reduces the H + concentration and increases the pH value [176,177].”
From Multi-Sensing Monitoring of the Microalgae Biomass Cultivation Systems for Biofuels and Added Value Products Synthesis—Challenges and Opportunities (2025) · cites this paper as [176]
Self-check
Percentages, sums and reported differences re-computed from the paper’s own numbers.
The self-check needs the paper’s full text.
Cites
[34] Chlorophylls and carotenoids: Pigments of photosynthetic biomembranes
Lichtenthaler, H. K. (1987) · Methods in Enzymology · doi:10.1016/0076-6879(87)48036-1 · Cited by 13,616 · see citing works
Chlorophyll fluorescence—a practical guide
Maxwell, K., & Johnson, G. N. (2000) · Journal of Experimental Botany · doi:10.1093/jexbot/51.345.659 · Cited by 9,347 · see citing works
Biogas upgrading and utilization: Current status and perspectives
Angelidaki, İ., Treu, L., Tsapekos, P., Luo, G., Campanaro, S., Wenzel, H., & Kougias, P. (2018) · Biotechnology Advances · doi:10.1016/j.biotechadv.2018.01.011 · Cited by 1,437 · see citing works
CO2 bio-mitigation using microalgae
Wang, B., Li, Y., Wu, N., & Lan, C. Q. (2008) · Applied Microbiology and Biotechnology · doi:10.1007/s00253-008-1518-y · Cited by 1,216 · see citing works
Handbook of Microalgal Culture: Applied Phycology and Biotechnology
(2013) · doi:10.1002/9781118567166 · Cited by 979 · see citing works
Muñoz, R., Meier, L., Díaz, I., & Jeison, D. (2015) · Reviews in Environmental Science and Bio/Technology · doi:10.1007/s11157-015-9379-1 · Cited by 680 · see citing works
Self-citationKumar, K., Dasgupta, C. N., Nayak, B., Lindblad, P., & Das, D. (2011) · Bioresource Technology · doi:10.1016/j.biortech.2011.01.054 · Cited by 533 · see citing works
Tolerance of microalgae to high CO2 and high temperature
Hanagata, N., Takeuchi, T., Fukuju, Y., Barnes, D. J., & Karube, I. (1992) · Phytochemistry · doi:10.1016/0031-9422(92)83682-o · Cited by 276 · see citing works
Photosynthetic CO2 uptake by microalgae: An attractive tool for biogas upgrading
Meier, L., Pérez, R., Azócar, L., Rivas, M., & Jeison, D. (2015) · Biomass and Bioenergy · doi:10.1016/j.biombioe.2014.10.032 · Cited by 147 · see citing works
Self-citationGrowth characteristics of Chlorella sorokiniana in airlift and bubble column photobioreactors
Kumar, K., & Das, D. (2012) · Bioresource Technology · doi:10.1016/j.biortech.2012.03.074 · Cited by 139 · see citing works
Serum-free production of recombinant proteins and adenoviral vectors by 293SF-3F6 cells
Côté, J., Garnier, A., Bernard Massie, B., & Kamen, A. (1998) · Biotechnology and Bioengineering · doi:10.1002/(sici)1097-0290(19980905)59:5 · Cited by 133 · see citing works
Sustained net CO2 evolution during photosynthesis by marine microorganism
Tchernov, D., Hassidim, M., Luz, B., Sukenik, A., Reinhold, L., & Kaplan, A. (1997) · Current Biology · doi:10.1016/s0960-9822(06)00330-7 · Cited by 109 · see citing works
Photosynthetic biogas upgrading using microalgae: Effect of light/dark photoperiod
Meier, L., Barros, P., Torres-Aravena, Á., Vı́lchez, C., & Jeison, D. (2017) · Renewable Energy · doi:10.1016/j.renene.2017.01.009 · Cited by 98 · see citing works
Self-citationEfficient CO2 capture from the air for high microalgal biomass production by a bicarbonate Pool
Zhu, C., Zhai, X., Xi, Y., Wang, J., Kong, F., Zhao, Y., & Chi, Z. (2020) · Journal of CO2 Utilization · doi:10.1016/j.jcou.2019.12.023 · Cited by 84 · see citing works
Papazi, A., Makridis, P., Divanach, P., & Kotzabasis, K. (2007) · Physiologia Plantarum · doi:10.1111/j.1399-3054.2007.01015.x · Cited by 62 · see citing works
Marín, D., Ortíz, A., Díez-Montero, R., Uggetti, E., Garcı́a, J., Lebrero, R., & Muñoz, R. (2019) · Bioresource Technology · doi:10.1016/j.biortech.2019.02.029 · Cited by 60 · see citing works
Vaquero, I., Ruiz‐Domínguez, M. C., Márquez, M., & Vı́lchez, C. (2012) · Process Biochemistry · doi:10.1016/j.procbio.2012.01.016 · Cited by 54 · see citing works
Ángeles, R., Vega-Quiel, M. J., Batista, A., Fernández‐Ramos, Ó., Lebrero, R., & Muñoz, R. (2021) · Algal Research · doi:10.1016/j.algal.2021.102350 · Cited by 45 · see citing works
Beigbeder, J., Sanglier, M., Dantas, J. M. D. M., & Lavoie, J. (2021) · Journal of CO2 Utilization · doi:10.1016/j.jcou.2021.101581 · Cited by 39 · see citing works
Franco‐Morgado, M., Tabaco-Angoa, T., Ramírez-García, M. A., & Sánchez, A. G. (2020) · Journal of Environmental Management · doi:10.1016/j.jenvman.2020.111813 · Cited by 37 · see citing works
Cuaresma, M., Garbayo, I., Vega, J. M., & Vı́lchez, C. (2006) · Enzyme and Microbial Technology · doi:10.1016/j.enzmictec.2005.10.049 · Cited by 36 · see citing works
Self-citationTsuzuki, M., Shiraiwa, Y., & Miyachi, S. (1980) · Plant and Cell Physiology · doi:10.1093/oxfordjournals.pcp.a076042 · Cited by 31 · see citing works
Marín, D., Carmona-Martínez, A. A., Lebrero, R., et al. (2020) · Fuel · doi:10.1016/j.fuel.2020.117999 · Cited by 31 · see citing works
Algae: Anatomy, Biochemistry, and Biotechnology by Barsanti, L. & Gualtieri, P.
Wehr, J. D. (2007) · Journal of Phycology · doi:10.1111/j.1529-8817.2007.00335.x · Cited by 25 · see citing works
Williams, T. G., & Colman, B. (1996) · Plant Cell & Environment · doi:10.1111/j.1365-3040.1996.tb00341.x · Cited by 25 · see citing works
Rocher-Rivas, R., Sánchez, A. G., Ulloa‐Mercado, G., et al. (2022) · Journal of environmental chemical engineering · doi:10.1016/j.jece.2022.108336 · Cited by 25 · see citing works
Keymer, P. C., Lant, P. A., & Pratt, S. (2013) · Journal of Applied Phycology · doi:10.1007/s10811-013-0146-9 · Cited by 22 · see citing works
Modeling and Analysis of an Absorption Column Connected to a Microalgae Culture
Martínez, C. A., Ávila, A. I., Mairet, F., Meier, L., & Jeison, D. (2020) · SIAM Journal on Applied Mathematics · doi:10.1137/18m1225641 · Cited by 3 · see citing works
Self-citationSaldarriaga, L. F., Almenglo, F., Cantero, D., & Ramírez, M. (2021) · Processes · doi:10.3390/pr9091503 · Cited by 2 · see citing works
Flagged first, then by citations
Research works printed but not linked: 1
- Stumm, W.; Morgan, J.J. Aquatic Chemistry: Chemical Equilibria and Rates in Natural Waters, 3rd Revised ed.; John Wiley & Sons Inc.: New York, NY, USA, 1995; ISBN 0471511854.
Cited by
Sorted by citations
Dębowski, M., Kazimierowicz, J., & Zieliński, M. (2025) · Applied Sciences · doi:10.3390/app15137324 · Cited by 30 · see citing works
- Authors
- Meier, L., Vilchez, C., Cuaresma, M., Torres-Aravena, Á., & Jeison, D.
- Affiliations
- Universidad de La Frontera (CL)
- Algal Biotechnology Group, CIDERTA and Faculty of Experimental Sciences, University of Huelva, Huelva Business Park, 21007 Huelva, Spain
- Universidad de Huelva (ES)
- Pontificia Universidad Católica de Valparaíso (CL)
- Corresponding author
- Torres-Aravena, Álvaro
- Venue
- Applied Sciences
- Publisher
- MDPI AG
- Published
- 2022-11-29
- Volume
- 12
- Issue
- 23
- Pages
- 12194
- ISSN
- 2076-3417 (ISSN-L)
- OpenAlex
- W4310990732
- Cited by
- 17
- References
- 29
- Citations by year
- 2026: 7 · 2025: 5 · 2024: 1 · 2023: 4
- FWCI
- 0.45
- Type
- journal article
- Language
- en
- Open access
- gold
- doi.org
- Licence
- Locations
- Applied Sciences (publishedVersion, cc-by)
- Omeka S (Universidad de La Frontera) (submittedVersion, cc-by-nc-nd)
- Repositorio Institucional de la Universidad de Huelva (Universidad de Huelva) (submittedVersion)
- DOAJ (DOAJ: Directory of Open Access Journals) (submittedVersion, cc-by-sa)
- Hispana (submittedVersion, cc-by-nc-nd)
- Repositorio Institucional de la Universidad de Huelva (Universidad de Huelva) (submittedVersion, cc-by-nc-nd)
- Funders
- Fondecyt-ANID Chile (1120488, 15130015, 039.315/2022)
- CRHIAM Centre (CONICYT/FONDAP) (1120488, 15130015, 039.315/2022)
- VRIEA-PUCV (1120488, 15130015, 039.315/2022)
- Topics
- Physical Sciences › Energy › Renewable Energy, Sustainability and the Environment › Algal biology and biofuel production
- Physical Sciences › Engineering › Mechanical Engineering › Carbon Dioxide Capture Technologies
- Life Sciences › Biochemistry, Genetics and Molecular Biology › Molecular Biology › Photosynthetic Processes and Mechanisms
- Keywords
- biogas upgrading, microalgae, Chlorella sorokiniana, pH change, carbon dioxide removal, photobioreactors, photosynthetic activity, PSII quantum yield
About these checks
Registry, retraction, Cites and statistics results are computed, not judged, with one exception: a printed reference that no index lists is read once by a model before it counts as a citation error. Claims are extracted by a model and kept only when their quote appears verbatim in the text; each cited source is then checked, with a model’s help, for whether it says what the claim relies on. Those verdicts can be wrong — read the claim’s quote and the cited source before relying on one.
Statistics and arithmetic are recomputed, not judged.
Confidence bands are shown only for fields calibrated on our annotated test set. None is calibrated yet, so no band is shown.
What counts as a claim ›How we measure confidence ›How we check this ›
Are you an author, or do you see a problem with this page? Request a review
