Anaerobic co-digestion of microalgae and primary sludge in an anaerobic membrane bioreactor for resource recovery (biogas and bionutrients) from urban wastewater

El consumo continuo de energía primaria ha motivado a la comunidad científica a buscar tecnologías que requieran un menor consumo de recursos y fuentes alternativas de energía renovable, que puedan sustituir a los combustibles fósiles. El cultivo de microalgas en combinación con tecnologías anaerobias surgió como una tecnología prometedora y sostenible en el ámbito del tratamiento de aguas residuales. La valorización de la biomasa de microalgas mediante la digestión anaerobia (AD) permite la producción de energía a partir de corrientes de residuos. Dado que la AD de microalgas presenta algunos inconvenientes que obstaculizan la eficiencia del proceso, se ha estudiado la co-digestión anaerobia (ACoD) con sustratos ricos en carbono, como residuos de papel o fangos, como alternativa para aumentar la eficiencia del proceso anaerobio. El presente estudio consiste en la evaluación a largo plazo de la ACoD de microalgas sin pretratar y fango primario. Para ello, la tecnología de ACoD se incluyó en un marco ambientalmente sostenible en el que la AD se utilizó en primer lugar para la eliminación de sustancias orgánicas de las aguas residuales decantadas; las microalgas cultivadas en una planta piloto de fotobiorreactores de membrana se utilizaron para la eliminación de nutrientes del efluente de la AD; y la biomasa microalgal y el fango primario se co- digirieron en un biorreactor de membrana anaerobio (AnMBR). Las microalgas y el fango primario se co-digirieron a escala de laboratorio y piloto y se evaluaron diferentes condiciones operacionales teniendo en cuenta los procesos biológicos, la filtración por membrana y la comunidad microbiana involucrada. La ACoD de microalgas y fango primario se estudió primero a escala de laboratorio, operando a diferentes tiempos de retención de sólidos (SRT), velocidad de carga orgánica (OLR) y temperatura. Los resultados indicaron que, cuanto mayor era el SRT y la OLR, mayor era la producción de metano, trabajando en un AnMBR. Los resultados de laboratorio también mostraron que el AnMBR termófilo alcanzaba una mayor producción de metano que el mesófilo. No obstante, los balances económicos y energéticos realizados para saber cuáles son las mejores condiciones de operación para escalar el proceso de laboratorio a escala piloto mostraron que un SRT de 70 d y las condiciones mesófilas eran las recomendables para operar la planta piloto de ACoD. Por tanto, en base a los resultados anteriores, la planta piloto de ACoD se operó durante un año a 70 d SRT y 35 oC. La planta piloto AnMBR alcanzó una biodegradabilidad del 62% y mostró una alta estabilidad en términos de pH y ácidos grasos volátiles. Se evaluó el proceso de filtración, indicando que la aplicación de la demanda específica de gas y un ciclo de contralavado por cada dos ciclos de filtración evitó la formación de fouling irreversible. Se ha demostrado que la ACoD de microalgas aumenta la producción de metano en comparación con la monodigestión de microalgas. La adición de un sustrato fácilmente biodegradable como fango primario a la biomasa microalgal tuvo un efecto sinérgico en la AD, creando una comunidad microbiana adaptada capaz de degradar ambos sustratos por vías sintróficas en las que microorganismos sintróficos como Smithella o W5 degradan intermediarios (especialmente propionato) y aumentan la producción de metano, principalmente llevada a cabo por metanógenos aceticlásticos como Methanosaeta. Los microorganismos hidrolíticos y fermentadores que intervienen en la degradación de las proteínas (por ejemplo, Coprothermobacter, Fervidobacterium o miembros de la familia Synergistaceae) y la degradación de la celulosa (por ejemplo, Defluviitoga o Thermogutta) también desempeñaron un papel importante en la degradación de ambos sustratos. En este trabajo se evaluó también la posible recuperación de nutrientes de los efluentes de la ACoD (permeado y digestato). El nitrógeno se recuperó del permeado con una eficiencia del 99% utilizando un contactor de membrana hidrofóbica de fibra hueca de polipropileno. El fósforo no se recuperó del permeado ya que el 74% se precipitó durante el proceso de AD. Los experimentos realizados con el digestato procedente de la ACoD en los reactores de compostaje Dewar, a escala laboratorio, demostraron que se puede aplicar un proceso de compostaje después de la ACoD, generando un material compostado estable e higienizado que podría utilizarse como enmienda orgánica. Esta tesis proporciona información novedosa sobre las ACoD de microalgas crudas y fango primario, ya que este proceso se estudió no solo a escala de laboratorio, sino también a escala piloto, lo que constituye un paso necesario para futuras aplicaciones a escala industrial. Se logró una alta estabilidad y una elevada degradación de los sustratos, (correspondiente a un alto rendimiento de metano) al co-digerir ambos sustratos debido a los efectos de sinergia encontrados entre los microorganismos y también debido a que se estaba utilizando la tecnología AnMBR, evitando la aplicación de costosos pretratamientos. Este proceso se enmarca en un escenario de economía circular en el que se están recuperando recursos (biogás, nutrientes y agua) de las aguas residuales urbanas.Continuous primary energy consumption has motivated the scientific community to search for less resource-demanding technologies and alternative renewable and eco- friendly energy sources that could substitute fossil fuels. Microalgae cultivation in combination with anaerobic technologies arose as a promising and sustainable technology in the field of wastewater treatment. Microalgae biomass valorisation through anaerobic digestion (AD) allows energy production from waste streams. Since microalgae AD presents some drawbacks that hinder process efficiency, anaerobic co-digestion (ACoD) with carbon-rich substrates such as waste paper or sludge has been studied as an alternative to increase anaerobic process efficiency. The present study consists in the long-term evaluation of raw microalgae and primary sludge ACoD. For this purpose, the ACoD technology was included in an environmentally sustainable framework in which AD was used first for organics removal from settled raw wastewater; microalgae cultivated in a membrane photobioreactor pilot plant were used for nutrients removal from the AD effluent; and microalgae biomass and primary sludge were co-digested in an anaerobic membrane bioreactor (AnMBR). Microalgae and primary sludge were co-digested at laboratory and pilot-scale and different operating conditions were evaluated considering biological processes, membrane filtration and microbial community involved. Microalgae and primary sludge ACoD was studied first at lab-scale, operating at different solids retention time (SRT), organic loading rate (OLR) and temperature. Results indicated that, the higher the SRT and the OLR, the higher the methane production, working in an AnMBR. Laboratory results also showed that thermophilic AnMBR achieved higher methane yield than the mesophilic one. Nevertheless, economic and energetic balances carried out to know which are the best operating conditions to scale up the process from laboratory to pilot-scale showed that 70 d SRT and mesophilic conditions were the recommendable ones to operate the ACoD pilot plant. Then, based on these results, the ACoD pilot plant was operated during a year at 70 d SRT and 35 oC. The pilot plant AnMBR achieved 62% organic matter biodegradability and showed high stability in terms of pH and volatile fatty acids. Filtration process was assessed, indicating that applying gas sparging and a backwash cycle every two filtration cycles avoided irreversible fouling formation. Microalgae ACoD has demonstrated to increase methane production compared to microalgae mono-digestion. Adding an easily biodegradable substrate as primary sludge to microalgae biomass had a synergetic effect on AD, creating an adapted microbial community capable of degrading both substrates through syntrophic pathways in which syntrophic microorganisms as Smithella or W5 degrade intermediates (especially propionate) and enhancing methane production, mainly carried out by aceticlastic methanogens as Methanosaeta. Hydrolytic and fermenters microorganisms involved in protein degradation (e.g. Coprothermobacter, Fervidobacterium, members of Synergistaceae family) and cellulose degradation (e.g. Defluviitoga, Thermogutta) also had an important role in both substrates degradation. This work also assessed potential nutrient recovery from ACoD effluents (permeate and digestate). Nitrogen was recovered from permeate with 99% efficiency using a hydrophobic polypropylene hollow-fibre membrane contactor. Phosphorus was not recovered from permeate since 74% was precipitated during AD process. Laboratory experiments with ACoD digestate carried out in Dewar reactors demonstrated that a composting process after ACoD can be applied, generating a stable and sanitised composted material that could be used as a soil improver. This thesis provides novel information on raw microalgae and primary sludge ACoD, since this process was studied not only at laboratory-scale, but also at pilot-scale, which is a necessary step for future applications at industrial-scale. High stability and high substrates degradation, corresponding to high methane yield, were achieved co-digesting both substrates due to the synergy effects found between microorganisms and also due to the use of AnMBR technology, avoiding the application of costly pretreatments. This process is enclosed in a circular economy scenario in which resources (biogas, nutrients and water) are being recovered from urban wastewater

Resource recovery from sulphate-rich sewage through an innovative anaerobic-based water resource recovery facility (WRRF)

[EN] This research work proposes an innovative water resource recovery facility (WRRF) for the recovery of energy, nutrients and reclaimed water from sewage, which represents a promising approach towards enhanced circular economy scenarios. To this aim, anaerobic technology, microalgae cultivation, and membrane technology were combined in a dedicated platform. The proposed platform produces a high-quality solid- and coliform-free effluent that can be directly discharged to receiving water bodies identified as sensitive areas. Specifically, the content of organic matter, nitrogen and phosphorus in the effluent was 45 mg COD.L-1 , 14.9 mg N.L-1 and 0.5 mg P.L-1 , respectively. Harvested solar energy and carbon dioxide biofixation in the form of microalgae biomass allowed remarkable methane yields (399 STP L CH 4.kg(-1) CODinf ) to be achieved, equivalent to theoretical electricity productions of around 0.52 kWh per m 3 of wastewater entering the WRRF. Furthermore, 26.6% of total nitrogen influent load was recovered as ammonium sulphate, while nitrogen and phosphorus were recovered in the biosolids produced (650 +/- 77 mg N.L-1 and 121.0 +/- 7.2 mg P.L-1).This research was supported by the Spanish Ministry of Economy and Competitiveness (MINECO, Projects CTM2014-54980-C2-1-R and CTM2014-54980-C2-2-R) jointly with the European Regional Development Fund (ERDF), which are gratefully acknowledged. This research was also supported by the Spanish Ministry of Education, Culture and Sport via two pre-doctoral FPU fellowships (FPU14/05082 and FPU15/02595) and by the Spanish Ministry of Economy and Competitiveness via two pre-doctoral FPI fellowships (BES-2015-071884, BES-2015-073403) and one Juan de la Cierva contract (FJCI-2014-21616). The authors would also like to acknowledge the support received from Generalitat Valenciana via two VALithornd post-doctoral grants (APOSTD/2014/049 and APOSTD/2016/104) and via the fellowships APOTI/2016/059 and CPI-16-155, as well as the financial aid received from the European Climate KIC association for the 'MAB 2.0' Project (APIN0057_ 2015-3.6-230_ P066-05) and Universitat Politecnica de Valencia via a pre-doctoral FPI fellowship to the seventh author.Seco Torrecillas, A.; Aparicio Antón, SE.; Gonzalez-Camejo, J.; Jiménez Benítez, AL.; Mateo-Llosa, O.; Mora-Sánchez, JF.; Noriega-Hevia, G.... (2018). Resource recovery from sulphate-rich sewage through an innovative anaerobic-based water resource recovery facility (WRRF). Water Science & Technology. 78(9):1925-1936. https://doi.org/10.2166/wst.2018.492S19251936789Bair, R. A., Ozcan, O. O., Calabria, J. L., Dick, G. H., & Yeh, D. H. (2015). Feasibility of anaerobic membrane bioreactors (AnMBR) for onsite sanitation and resource recovery (nutrients, energy and water) in urban slums. Water Science and Technology, 72(9), 1543-1551. doi:10.2166/wst.2015.349Barat, R., Serralta, J., Ruano, M. V., Jiménez, E., Ribes, J., Seco, A., & Ferrer, J. (2013). Biological Nutrient Removal Model No. 2 (BNRM2): a general model for wastewater treatment plants. Water Science and Technology, 67(7), 1481-1489. doi:10.2166/wst.2013.004Batstone, D. J., Hülsen, T., Mehta, C. M., & Keller, J. (2015). Platforms for energy and nutrient recovery from domestic wastewater: A review. Chemosphere, 140, 2-11. doi:10.1016/j.chemosphere.2014.10.021Bilad, M. R., Arafat, H. A., & Vankelecom, I. F. J. (2014). Membrane technology in microalgae cultivation and harvesting: A review. Biotechnology Advances, 32(7), 1283-1300. doi:10.1016/j.biotechadv.2014.07.008Carrington E.-G. 2001 Evaluation of Sludge Treatments for Pathogen Reduction. http://europa.eu.int/comm/environment/pubs/home.htm.Cookney, J., Mcleod, A., Mathioudakis, V., Ncube, P., Soares, A., Jefferson, B., & McAdam, E. J. (2016). Dissolved methane recovery from anaerobic effluents using hollow fibre membrane contactors. Journal of Membrane Science, 502, 141-150. doi:10.1016/j.memsci.2015.12.037De Morais, M. G., & Costa, J. A. V. (2007). Biofixation of carbon dioxide by Spirulina sp. and Scenedesmus obliquus cultivated in a three-stage serial tubular photobioreactor. Journal of Biotechnology, 129(3), 439-445. doi:10.1016/j.jbiotec.2007.01.009Giménez, J. B., Robles, A., Carretero, L., Durán, F., Ruano, M. V., Gatti, M. N., … Seco, A. (2011). Experimental study of the anaerobic urban wastewater treatment in a submerged hollow-fibre membrane bioreactor at pilot scale. Bioresource Technology, 102(19), 8799-8806. doi:10.1016/j.biortech.2011.07.014Giménez, J. B., Martí, N., Ferrer, J., & Seco, A. (2012). Methane recovery efficiency in a submerged anaerobic membrane bioreactor (SAnMBR) treating sulphate-rich urban wastewater: Evaluation of methane losses with the effluent. Bioresource Technology, 118, 67-72. doi:10.1016/j.biortech.2012.05.019Giménez, J. B., Bouzas, A., Carrere, H., Steyer, J.-P., Ferrer, J., & Seco, A. (2018). Assessment of cross-flow filtration as microalgae harvesting technique prior to anaerobic digestion: Evaluation of biomass integrity and energy demand. Bioresource Technology, 269, 188-194. doi:10.1016/j.biortech.2018.08.052González-Camejo, J., Serna-García, R., Viruela, A., Pachés, M., Durán, F., Robles, A., … Seco, A. (2017). Short and long-term experiments on the effect of sulphide on microalgae cultivation in tertiary sewage treatment. Bioresource Technology, 244, 15-22. doi:10.1016/j.biortech.2017.07.126Martí, N., Barat, R., Seco, A., Pastor, L., & Bouzas, A. (2017). Sludge management modeling to enhance P-recovery as struvite in wastewater treatment plants. Journal of Environmental Management, 196, 340-346. doi:10.1016/j.jenvman.2016.12.074Moosbrugger R. , WentzelM. & EkamaG.1992Simple Titration Procedures to Determine H2CO3 Alkalinity and Short-chain Fatty Acids in Aqueous Solutions Containing Known Concentrations of Ammonium, Phosphate and Sulphide Weak Acid/Bases. Water. Res. Commission, Report, No. TT 57/92.Morales, N., Boehler, M., Buettner, S., Liebi, C., & Siegrist, H. (2013). Recovery of N and P from Urine by Struvite Precipitation Followed by Combined Stripping with Digester Sludge Liquid at Full Scale. Water, 5(3), 1262-1278. doi:10.3390/w5031262Pretel, R., Durán, F., Robles, A., Ruano, M. V., Ribes, J., Serralta, J., & Ferrer, J. (2015). Designing an AnMBR-based WWTP for energy recovery from urban wastewater: The role of primary settling and anaerobic digestion. Separation and Purification Technology, 156, 132-139. doi:10.1016/j.seppur.2015.09.047Pretel, R., Robles, A., Ruano, M. V., Seco, A., & Ferrer, J. (2016). Economic and environmental sustainability of submerged anaerobic MBR-based (AnMBR-based) technology as compared to aerobic-based technologies for moderate-/high-loaded urban wastewater treatment. Journal of Environmental Management, 166, 45-54. doi:10.1016/j.jenvman.2015.10.004Sharma, B., Sarkar, A., Singh, P., & Singh, R. P. (2017). Agricultural utilization of biosolids: A review on potential effects on soil and plant grown. Waste Management, 64, 117-132. doi:10.1016/j.wasman.2017.03.002Sialve, B., Bernet, N., & Bernard, O. (2009). Anaerobic digestion of microalgae as a necessary step to make microalgal biodiesel sustainable. 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Maximizing resource recovery from urban wastewater through an innovative facility layout

[EN] This research work proposes an innovative layout for urban wastewater treatment based on anaerobic technology, microalgal cultivation and membrane technology. The proposed Water Resource Recovery Facility (WRRF) system can treat urban wastewater efficiently, complying with legal discharge limits and allowing for resource recovery, i.e. energy, nutrients and reclaimed water. In addition, the proposed layout produces less solid wastes than a conventional wastewater treatment plant (WWTP) and it is possible to recover energy as biogas, not only from the original wastewater sources but also from the biomass generated in the WRRF system

The Seventeenth Data Release of the Sloan Digital Sky Surveys: Complete Release of MaNGA, MaStar and APOGEE-2 Data

This paper documents the seventeenth data release (DR17) from the Sloan Digital Sky Surveys; the fifth and final release from the fourth phase (SDSS-IV). DR17 contains the complete release of the Mapping Nearby Galaxies at Apache Point Observatory (MaNGA) survey, which reached its goal of surveying over 10,000 nearby galaxies. The complete release of the MaNGA Stellar Library (MaStar) accompanies this data, providing observations of almost 30,000 stars through the MaNGA instrument during bright time. DR17 also contains the complete release of the Apache Point Observatory Galactic Evolution Experiment 2 (APOGEE-2) survey which publicly releases infra-red spectra of over 650,000 stars. The main sample from the Extended Baryon Oscillation Spectroscopic Survey (eBOSS), as well as the sub-survey Time Domain Spectroscopic Survey (TDSS) data were fully released in DR16. New single-fiber optical spectroscopy released in DR17 is from the SPectroscipic IDentification of ERosita Survey (SPIDERS) sub-survey and the eBOSS-RM program. Along with the primary data sets, DR17 includes 25 new or updated Value Added Catalogs (VACs). This paper concludes the release of SDSS-IV survey data. SDSS continues into its fifth phase with observations already underway for the Milky Way Mapper (MWM), Local Volume Mapper (LVM) and Black Hole Mapper (BHM) surveys

Anaerobic Membrane Bioreactor for Microalgae and Primary Sludge Co-Digestion at Pilot Scale: Instrumentation, Control and Automation Implementation, and Performance Assessment

Anaerobic membrane bioreactor (AnMBR) technology is gaining interest for circular economy integration in the water sector. However, its complexity, arising from the integration of anaerobic processes with membrane technology, poses a key challenge. Developing an appropriate instrumentation, control, and automation (ICA) system is essential for its reliable long-term operation. In this study, an ICA system was developed to successfully manage an AnMBR pilot plant co-digesting two waste streams (microalgae and primary sludge). The ICA implementation enabled its stable longterm operation for 576 days, ensuring the proper performance of biological and filtration processes and yielding 215 NmLCH4 gCODinf 1 at 35 C. Variables such as temperature, oxidation-reduction potential, permeate flux and biogas flow were identified as key parameters and controlled. This included a 23% reduction in the integral of absolute error compared to a PID controller for permeate flow and the maintenance of a 0.5% standard deviation for digester temperature. These controls enabled AnMBR performance optimization, the rapid detection of process issues, and early corrective actions. As a start-up strategy to ensure proper filtration performance in the long term, critical flux tests were conducted, guaranteeing a competitive total annualized equivalent cost of 0.0016 EUR/m3 for optimal conditions. The study also calculated greenhouse gas emissions in different scenarios, proposing optimal and more sustainable pilot plant operations, mesophilic conditions, biogas upgrading through microalgae cultivation, and grid injection, reducing emissions by 423 kgCO2e tCOD1. To ensure the viability of emerging technologies such as AnMBR, proper start-up protocols are crucial, including favorable filtration and biological process operating conditions, ICA implementation, and key parameter control for technical, economic and environmental success

Anaerobic Membrane Bioreactor for Microalgae and Primary Sludge Co-Digestion at Pilot Scale: Instrumentation, Control and Automation Implementation, and Performance Assessment

Anaerobic membrane bioreactor (AnMBR) technology is gaining interest for circular economy integration in the water sector. However, its complexity, arising from the integration of anaerobic processes with membrane technology, poses a key challenge. Developing an appropriate instrumentation, control, and automation (ICA) system is essential for its reliable long-term operation. In this study, an ICA system was developed to successfully manage an AnMBR pilot plant co-digesting two waste streams (microalgae and primary sludge). The ICA implementation enabled its stable long-term operation for 576 days, ensuring the proper performance of biological and filtration processes and yielding 215 NmLCH4·gCODinf−1 at 35 °C. Variables such as temperature, oxidation-reduction potential, permeate flux and biogas flow were identified as key parameters and controlled. This included a 23% reduction in the integral of absolute error compared to a PID controller for permeate flow and the maintenance of a 0.5% standard deviation for digester temperature. These controls enabled AnMBR performance optimization, the rapid detection of process issues, and early corrective actions. As a start-up strategy to ensure proper filtration performance in the long term, critical flux tests were conducted, guaranteeing a competitive total annualized equivalent cost of 0.0016 EUR/m3 for optimal conditions. The study also calculated greenhouse gas emissions in different scenarios, proposing optimal and more sustainable pilot plant operations, mesophilic conditions, biogas upgrading through microalgae cultivation, and grid injection, reducing emissions by 423 kgCO2e·tCOD−1. To ensure the viability of emerging technologies such as AnMBR, proper start-up protocols are crucial, including favorable filtration and biological process operating conditions, ICA implementation, and key parameter control for technical, economic and environmental success

Global sensitivity and uncertainty analysis of a microalgae model for wastewater treatment

[EN] The results of a global sensitivity and uncertainty analysis of a microalgae model applied to a Membrane Photobioreactor (MPBR) pilot plant were assessed. The main goals of this study were: (I) to identify the sensitivity factors of the model through the Morris screening method, i.e. the most influential factors; (II) to calibrate the influential factors online or offline; and (III) to assess the model's uncertainty. Four experimental periods were evaluated, which encompassed a wide range of environmental and operational conditions. Eleven influential factors (e.g. maximum specific growth rate, light intensity and maximum temperature) were identified in the model from a set of 34 kinetic parameters (input factors). These influential factors were preferably calibrated offline and alternatively online. Offline/online calibration provided a unique set of model factor values that were used to match the model results with experimental data for the four experimental periods. A dynamic optimization of these influential factors was conducted, resulting in an enhanced set of values for each period. Model uncertainty was assessed using the uncertainty bands and three uncertainty indices: p-factor, r-factor and ARIL. Uncertainty was dependent on both the number of influential factors identified in each period and the model output analyzed (i.e. biomass, ammonium and phosphate concentration). The uncertainty results revealed a need to apply offline calibration methods to improve model performance.This research work was supported by the Spanish Ministry of Economy and Competitiveness (MINECO, Projects CTM2014-54980-C2-1-R, CTM2014-54980-C2-2-R, CTM2017-86751-C2-1-R and CTM2017-86751-C2-2-R) jointly with the European Regional Development Fund (ERDF) , both of which are gratefully acknowledged. It was also supported by the Spanish Ministry of Education, Culture and Sport via a pre-doctoral FPU fellowship to author Stephanie Aparicio (FPU/15/02595) .Aparicio, S.; Serna-García, R.; Seco, A.; Ferrer, J.; Borrás Falomir, L.; Robles, Á. (2022). Global sensitivity and uncertainty analysis of a microalgae model for wastewater treatment. Science of The Total Environment. 806(1):1-15. https://doi.org/10.1016/j.scitotenv.2021.150504115806

Unraveling prevalence of homoacetogenesis and methanogenesis pathways due to inhibitors addition

Three inhibitors targeting different microorganisms, both from Archaea and Bacteria domains, were evaluated for their effect on CO2 biomethanation: sodium ionophore III (ETH2120), carbon monoxide (CO), and sodium 2-bromoethanesulfonate (BES). This study examines how these compounds affect the anaerobic digestion microbiome in a biogas upgrading process. While archaea were observed in all experiments, methane was produced only when adding ETH2120 or CO, not when adding BES, suggesting archaea were in an inactivated state. Methane was produced mainly via methylotrophic methanogenesis from methylamines. Acetate was produced at all conditions, but a slight reduction on acetate production (along with an enhancement on CH4 production) was observed when applying 20 kPa of CO. Effects on CO2 biomethanation were difficult to observe since the inoculum used was from a real biogas upgrading reactor, being this a complex environmental sample. Nevertheless, it must be mentioned that all compounds had effects on the microbial community composition

Biologically-mediated CO2 capture by Cupriavidus necator for polyhydroxyalkanoates production and biogas upgrading

Cupriavidus necator is a microorganism known for its ability to store polyhydroxyalkanoates (PHA), which are bioplastics that are increasingly being used to replace plastics obtained from chemical compounds of fossil origin. C. necator uses O2 as electron acceptor and H2 as electron donor for CO2 uptake. The conversion of CO2 to PHA by C. necator has been demonstrated in previous studies. This process allows the removal of a greenhouse gas combined with the simultaneous production of a value-added product (PHA). In this study, different conditions and carbon sources were tested for C. necator growth based on previous metabolic flux-balance simulations. Different carbon sources, including glucose, pure CO2, biogas (containing 40% of CO2) and digestate containing a high concentration of volatile fatty acids were used for growing C. necator. Cultures were grown in aerobic and microaerophilic conditions (O2 concentration between 2-5%). The cultures were also exposed to different CH4 and CO2 concentrations to evaluate potential toxic effects on the species under investigation. The maximum growth was achieved at aerobic conditions, both with glucose or CO2 as carbon source. A minimum of around 5% of O2 was needed for the microorganism to grow. CH4 was found not to be toxic for C. necator, so, biogas could be feed to this culture with a minimum amount of O2 in a full-scale process, allowing the biogas upgrading. It is expected that the simultaneous removal of CO2 present in biogas and the externally provided O2 can lead to biogas upgrade to biomethane which can be injected into the gas grid

The Seventeenth Data Release of the Sloan Digital Sky Surveys:complete release of MaNGA, MaStar and APOGEE-2 data

This paper documents the seventeenth data release (DR17) from the Sloan Digital Sky Surveys; the fifth and final release from the fourth phase (SDSS-IV). DR17 contains the complete release of the Mapping Nearby Galaxies at Apache Point Observatory (MaNGA) survey, which reached its goal of surveying over 10,000 nearby galaxies. The complete release of the MaNGA Stellar Library accompanies this data, providing observations of almost 30,000 stars through the MaNGA instrument during bright time. DR17 also contains the complete release of the Apache Point Observatory Galactic Evolution Experiment 2 survey that publicly releases infrared spectra of over 650,000 stars. The main sample from the Extended Baryon Oscillation Spectroscopic Survey (eBOSS), as well as the subsurvey Time Domain Spectroscopic Survey data were fully released in DR16. New single-fiber optical spectroscopy released in DR17 is from the SPectroscipic IDentification of ERosita Survey subsurvey and the eBOSS-RM program. Along with the primary data sets, DR17 includes 25 new or updated value-added catalogs. This paper concludes the release of SDSS-IV survey data. SDSS continues into its fifth phase with observations already underway for the Milky Way Mapper, Local Volume Mapper, and Black Hole Mapper surveys