Work

Bacteria-microalgae interactions during nitrification/denitrification processes in a photobioreactor treating swine wastewater.

Year: 2013

Type: article

Abstract: The economic feasibility of photobioreactors for the production of valuable microalgae feedstock can be limited to some extent by the nitrogen (N) and phosphorus (P) fertilizers costs.In this regard, N-and P-rich residues from agribusiness have been widely considered for microalgae cultivation.Therefore, the use of photobioreactors not only constitutes a promising engineered technology to generate valuable feedstock for renewable energy but can also serve as an alternative tertiary treatment for swine nutrient-rich wastewaters.The objective of this study was to investigate the interaction between naturally occurring anaerobic biodigestion effluent wastewater bacteria and Chlorella sp.during nitrogen removal by nitrification/ denitrification processes within a photobioreactor.qPCR assays were used to quantify the abundance of total bacteria (16S rDNA) and denitrifiers (nirS).Ammonia removal coincided with the increasing growth of total bacteria (1.2×10 10 copies L -1 at 48 h) and accumulation of NO 3 and NO 2 intermediates.Low oxygen concentrations prevailed (< 0.2 mg/L) in the photobioreactor during dark periods and low microalgae biomass (up to 48 h) thus stimulating the growth of denitrifying bacteria (1.8×10 6 copies L -1 at 48 h).NO 3 accumulation coincided with denitrification inhibition by the increased dissolved oxygen-derived photosynthesis.Overall, the oxidative-reductive environment encountered in a non-sterile photobioreactor can benefit swine wastewater nutrient removal by the simultaneous enhancement of nitrification and denitrification processes.This is particularly important since the application of external oxygen sources to maintain nitrification processes can be costly and/ or insufficient to warrant adequate bacterial metabolism.

Source: Portuguese National Funding Agency for Science, Research and Technology (RCAAP Project by FCT)

Authors: MEZZARI, M. P., SILVA, M. L. B. da, VIANCELLI, A., IBELLI, A. M. G., KUNZ, A., SOARES, H. M.

Institution: Embrapa

Language: English

Topic: Algal biology and biofuel production

Subfield: Renewable Energy, Sustainability and the Environment

Field: Energy

Domain: Physical Sciences

SDGs: Clean water and sanitation, Responsible consumption and production

Open Access status: green

Funder: Coordenação de Aperfeiçoamento de Pessoal de Nível Superior

OpenAlex ID: W6989457379

FWCI: 0.131

Cites:

Cited by: 3

Related to: 10