Microalgae-bacteria gas exchange in wastewater: how mixotrophy may reduce the oxygen supply for bacteria
Autor: | Martina Pastore, Eleonora Sforza, Alberto Bertucco, Alessandro Spagni |
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Přispěvatelé: | Spagni, A. |
Rok vydání: | 2018 |
Předmět: |
0106 biological sciences
Health Toxicology and Mutagenesis Microbial Consortia Chlorella 010501 environmental sciences Mass balance Wastewater 01 natural sciences Environmental Water Purification Chlorella protothecoides Respirometry Nutrient Chlorella protothecoide 010608 biotechnology Microalgae Environmental Chemistry Waste Water Organic carbon 0105 earth and related environmental sciences Biological Oxygen Demand Analysis Bacteria Sewage Chemistry Oxygen supply Chemical oxygen demand Heterotrophic Processes General Medicine Biodegradation Carbon Dioxide Pulp and paper industry Activated sludge Pollution Oxygen Biodegradation Environmental Sewage treatment Mixotroph |
Zdroj: | Environmental science and pollution research international. 25(28) |
ISSN: | 1614-7499 |
Popis: | Microalgae-bacteria consortia application to wastewater treatment is considered as a potential and cheap strategy towards a self-sustaining oxygen-carbon dioxide gas exchange. However, microalgae can also carry out mixotrophy, thus reducing the net oxygen production, due to consumption of organic substrates. In this work, respirometric tests were used to quantify the oxygen reduction in the presence of biodegradable COD (chemical oxygen demand), which resulted up to 70%, depending on the biodegradability of the carbon substrate. The implication of mixotrophic metabolism on nutrient removal in urban wastewater was also measured by co-cultivating C. protothecoides with bacteria from activated sludge. To better understand the contribution of different populations, ad hoc experiments under controlled conditions were designed to quantify the nutrient consumption of bacteria and microalgae. Microalgae and bacteria were cultivated together and separately, with and without external bubbling, so to better ascertain the specific role of gas production and nutrient removal. Results showed that microalgae can remove up to 100 and 85% of P and N respectively, but the contribution on COD consumption may affect the net O2 supply to heterotrophic bacteria. However, a mutual COD consumption by microalgae and bacteria was proved by both experimental growth curves and mass balance application, based on stoichiometry experimentally adjusted. © 2018, Springer-Verlag GmbH Germany, part of Springer Nature. |
Databáze: | OpenAIRE |
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