15 research outputs found
Monitoring biological wastewater treatment processes: Recent advances in spectroscopy applications
Biological processes based on aerobic and anaerobic technologies have been continuously developed to wastewater treatment and are currently routinely employed to reduce the contaminants discharge levels in the environment. However, most methodologies commonly applied for monitoring key parameters are labor intensive, time-consuming and just provide a snapshot of the process. Thus, spectroscopy applications in biological processes are, nowadays, considered a rapid and effective alternative technology for real-time monitoring though still lacking implementation in full-scale plants. In this review, the application of spectroscopic techniques to aerobic and anaerobic systems is addressed focusing on UV--Vis, infrared, and fluorescence spectroscopy. Furthermore, chemometric techniques, valuable tools to extract the relevant data, are also referred. To that effect, a detailed analysis is performed for aerobic and anaerobic systems to summarize the findings that have been obtained since 2000. Future prospects for the application of spectroscopic techniques in biological wastewater treatment processes are further discussed.The authors thank the Portuguese Foundation for Science and Technology (FCT) under the scope of the strategic funding of UID/BIO/04469/2013 unit, COMPETE 2020 (POCI-01-0145-FEDER-006684) and the project RECI/BBB-EBI/0179/2012 (FCOMP-01-0124-FEDER-027462) and BioTecNorte operation (NORTE-01-0145-FEDER-000004) funded by the European Regional Development Fund under the scope of Norte2020 - Programa Operacional Regional do Norte. The authors also acknowledge the ïŹnancial support to Daniela P. Mesquita and Cristina Quintelas through the postdoctoral Grants (SFRH/BPD/82558/2011 and SFRH/BPD/101338/2014) provided by FCT - Portugal.info:eu-repo/semantics/publishedVersio
Impact de la nature de lâeffluent (synthĂ©tique ou rĂ©el) sur les performances dâun biorĂ©acteur Ă membranes en conditions stationnaires
National audienceno abstrac
Impact of synthetic or real urban wastewater on membrane bioreactor (MBR) performances and membrane fouling under stable conditions
International audienceno abstrac
CaracteÌrisation de la matrice exopolymeÌrique (EPS) de boues biologiques : apport de la chromatographie d'exclusion steÌrique
Cd(II) and Pb(II) sorption by extracellular polymeric substances (EPS) extracted from anaerobic granular biofilms: Evidence of a pH sorption-edge
International audienc
Role of extracellular polymeric substances (EPS) production in bioaggregation: application to wastewater treatment
This paper reviews the formation, structure, and stability of bioaggregates with an emphasis on the composition and distribution of extracellular polymeric substances (EPS) and their role in bioaggregation. Bioaggregation is ubiquitous in natural environment and is of great importance in biological wastewater treatment processes. It greatly influences the flocculability, settleability, and dewaterability for flocs and sludge retention and shear resistance for biofilms. The physico-chemical and microbial structures of bioaggregates are dependent on operational conditions as well as microbial diversity and spatial distribution. The formation of bioaggregates is mediated by the physico-chemical interactions as well as the microbial interactions such as EPS production and quorum sensing. EPS are composed of a mixture of macromolecules including proteins, polysaccharides, humic-like substances, and nucleic acids, which entrap the microbial cells in a three-dimensional matrix. The composition and physico-chemical characteristics of EPS have significant influence on the maintenance of the bioaggregate structure and the process performance of the wastewater treatment. However, the mechanisms of bioaggregation are still unclear and the conclusions on the role of EPS were mostly drawn from the established correlations and hypotheses. This paper expects to provide up-to-date knowledge on bioaggregation and insights for further studies and applications
Quantitative and qualitative characterization of extracellular polymeric substances from Anammox enrichment
Extracellular polymeric substances (EPS) from different Anammox biomass were extracted and characterized by quantitative and qualitative analysis to investigate the link between their characteristics and the enrichment process in lab scale bioreactors. Quantitatively, a decrease of protein to polysaccharide ratio and an increase in total EPS extraction yield were observed during the enrichment process. In the three dimensional excitation emission matrixes, the spectra showed similar location of the fluorescence peaks for all of the samples. Whereas, samples extracted from sludge containing enriched Anammox bacteria possessed two distinct peaks in the low excitation wavelength range (220â230 nm). Multi-excitation peaks might occur as evidenced by the identical fluorescence chromatograms after size exclusion chromatography (SEC) separation at excitation/emission wavelength of 221/350 nm and 280/330 nm. With the process of Anammox enrichment, UV chromatogram at 210 nm after SEC, which is an indicator of polysaccharides, showed increase in both intensity and number of peaks. However, all fluorescence chromatograms, which reflect proteins and soluble microbial by-products, showed similar peak patterns with increased intensity. An increase of EPS hydrophobicity was observed during the enrichment process for both reactors
Interest of florescence detection to determine Proteins and Humic-like substances fingerprints of ExoPolymeric Substances (EPS) from biological sludges performed by Size Exclusion Chromatography (SEC)
International audienc
Enrichment of Anammox Biomass from Different Seeding Sludge: Process Strategy and Microbial Diversity
The current study aims to tackle one of the main obstacles in the application of anaerobic ammonium oxidation (Anammox) technology, i.e., the extreme slow growth of the Anammox bacteria. Three conventional sludge has been tested in sequencing batch reactor for Anammox enrichment, including conventional aerobic sludge, denitrification sludge, and anaerobic sludge. With a high selection stress and insufficient oxygen control, the reactor seeded with aerobic sludge reached 50â60% total nitrogen removal after 240 days whereas that seeded with anaerobic sludge failed to establish Anammox activity. Anammox process was successfully established in the reactor seeded with denitrification sludge with a total nitrogen removal of approximately 80% after 150 days under strict oxygen control (DO <0.2 mg/L) and low selection stress. Under the same operational condition, the reactor seeded with anaerobic sludge reached only 20â30% total nitrogen removal. All the reactors experienced fluctuating performances during the enrichment process, which was believed to be the consequence of inhibitory factors such as dissolved oxygen, nitrite and free ammonia as well as undesirable coexisting bacteria which compete for the same substrate. The denaturing gradient gel electrophoresis (DGGE) band from the amplified DNA samples extracted from different enrichment stage showed a clear evolution of the microbial composition as reflected by the change in the band locations and their intensity