Analysis of a photobioreactor scaling up for tertiary wastewater treatment: denitrification, phosphorus removal, and microalgae production

The present work studies the removal of nutrients (nitrate and phosphate) from a synthetic wastewater simulating a secondary treatment effluent using the microalgae Chlorella vulgaris in autotrophic photobioreactors, together with an analysis of the critical points affecting the scaling-up process f...

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Bibliographic Details
Authors: Villaseñor Camacho, José, Fernández Marchante, Carmen María, RODRIGUEZ, LUIS
Format: article
Publication Date:2018
Country:España
Institution:Universidad de Castilla-La Mancha
Repository:RUIdeRA. Repositorio Institucional de la UCLM
OAI Identifier:oai:ruidera.uclm.es:10578/29257
Online Access:http://hdl.handle.net/10578/29257
Access Level:Open access
Keyword:Ingeniería Química
Fotobiorreactor
Aguas residuales
Desnitrificación
Eliminación de fósforo
Producción de microalgas
Chlorella vulgaris
Description
Summary:The present work studies the removal of nutrients (nitrate and phosphate) from a synthetic wastewater simulating a secondary treatment effluent using the microalgae Chlorella vulgaris in autotrophic photobioreactors, together with an analysis of the critical points affecting the scaling-up process from laboratory to pilot scale. Laboratory experiments were done in open agitated 1-L photobioreactors under batch operation mode, while pilot-scale experiments were done using a 150-L closed tubular photobioreactor under continuous operation mode. In both scales, nitrate was the limiting substrate and the effect of its concentration on microalgae performance was studied. From laboratory experiments, an average microalgae productivity of 85 mgVSS L−1 day−1 and approximate maximum N-NO3− and P-PO43− removal rates of 8 mg N gVSS−1 day−1, and 2.6 mg P gVSS−1 day−1 were found. Regarding pilot scale, the average microalgae productivity slightly decreased (76 mgVSS L−1 day−1) while the approximate maximum N-NO3− and P-PO43− removal rates slightly were increased (11.7 mg N gVSS−1 day−1 and 3.04 mg P gVSS−1 day−1) with respect to the laboratory-scale results. The pilot-scale operation worked under lower levels of turbulence and higher dissolved oxygen concentration and light intensity than laboratory experiments; those parameters were difficult to control and they can be identified as the critical points in the differences found on both nutrient removal and microalgae production.