Assessment of the flat-pannel membrane photobioreactor technology for wastewater treatment: Outdoor application to treat the effluent of an anaerobic membrane bioreactor

Tesis por compendio[ES] La combinación de reactores anaerobios de membranas (AnMBRs) con el cultivo de microalgas en un fotobiorreactor de membranas (MPBR) aparece como una opción ideal dentro del marco de tecnologías sostenibles para la depuración de aguas residuales. Con esta combinación de tecnologías, se puede obtener biogás a partir de la materia orgánica presente en el agua residual, mientras que los nutrientes del efluente de AnMBR se recuperan con la biomasa algal. Además, la tecnología de membranas permite obtener un efluente limpio y apto para su reutilización. Estudios previos han demostrado la capacidad de un cultivo de microalgas para recuperar los nutrientes presentes en el efluente de un sistema AnMBR a escala laboratorio. Sin embargo, el traslado de esta tecnología a condiciones controladas de laboratorio a condiciones ambientales variables puede suponer una limitación en su aplicación industrial. Este trabajo consiste en la evaluación del proceso de cultivo de microalgas en una planta piloto MPBR alimentada con el efluente de un sistema AnMBR. Para ello se han evaluado las condiciones óptimas de operación de la planta, teniendo en cuenta tanto el proceso biológico de microalgas como la velocidad de ensuciamiento de las membranas. También se ha estudiado el efecto de otros parámetros que influyen en el proceso, como la intensidad de luz aplicada a los fotobiorreactores (PBRs), temperatura, concentración de materia orgánica, presencia de otros organismos, etc.; así como el peso específico de cada parámetro dentro del proceso. Otro objetivo consiste en la búsqueda de nuevos parámetros de control del proceso que faciliten la operación en continuo del sistema. El sistema MPBR utilizado en este estudio se mostró capaz de tratar un efluente de AnMBR, cumpliendo con los límites legales de vertido. Sin embargo, esta operación se consiguió únicamente cuando se cumplían una serie de condiciones: i) El espesor de los fotobiorreactores era estrecho (10 cm). ii) Las condiciones de operación (BRT y HRT) se mantenían dentro del rango adecuado. iii) Temperatura se mantenía habitualmente debajo del límite máximo de 30 ºC. iv) No existía acumulación de nitrito. v) La fuente principal de nitrógeno era amonio. vi) La materia orgánica presente en el cultivo no era excesiva.[CA] La combinació de reactors anaerobis de membranes (AnMBRs) amb el cultiu de microalgues en un fotobioreactor de membranes (MPBR) apareix com una opció ideal dins el marc de tecnologies sostenibles per a la depuració d'aigües residuals. Amb aquesta combinació de tecnologies, es pot obtenir biogàs a partir de la matèria orgànica present en l'aigua residual, mentre que els nutrients de l'efluent de AnMBR es recuperen amb la biomassa algal. A més, la tecnologia de membranes permet obtenir un efluent net i apte per a la seua reutilització. Estudis previs han demostrat la capacitat d'un cultiu de microalgues per recuperar els nutrients presents en l'efluent d'un sistema AnMBR a escala laboratori. No obstant això, el trasllat d'aquesta tecnologia de condicions controlades de laboratori a condicions ambientals variables pot suposar una limitació en la seua aplicació industrial. Aquest treball consisteix en l'avaluació del procés de cultiu de microalgues en una planta pilot MPBR alimentada amb l'efluent d'un sistema AnMBR. Per a això s'han avaluat les condicions òptimes d'operació de la planta, tenint en compte tant el procés biològic de microalgues com la velocitat d'embrutiment de les membranes. També s'ha estudiat l'efecte d'altres paràmetres que influeixen en el procés, com la intensitat de llum aplicada als fotobioreactors (PBRs), temperatura, concentració de matèria orgànica, presència d'altres organismes, etc .; així com el pes específic de cada paràmetre dins del procés. Un altre objectiu consisteix en la recerca de nous paràmetres de control del procés que facilitin l'operació en continu del sistema. El sistema MPBR utilitzat en aquest estudi es va mostrar capaç de tractar un efluent de AnMBR, complint amb els límits legals d'abocament. No obstant això, aquesta operació es va aconseguir únicament quan es complien una sèrie de condicions: i) El gruix dels fotobioreactors era estret (10 cm). ii) Les condicions d'operació (BRT i HRT) es mantenien dins del rang adequat. iii) La temperatura es mantenia habitualment baix del límit màxim de 30 ºC. iv) No existia acumulació de nitrit. v) La font principal de nitrogen era amoni. vi) La matèria orgànica present en el cultiu no era excessiva.[EN] The combination of anaerobic membrane reactors (AnMBRs) and microalgae membrane photobioreactor (MPBR) appears as an ideal option within the framework of sustainable technologies for wastewater treatment. This combination enables to produce biogas from the organic matter present in wastewater, while the nutrient content of the AnMBR effluent can be recovered from microalgae biomass. In addition, membrane technology allows obtaining a water effluent which can be suitable for reclamation. Previous studies have proved the capability of a microalgae culture to recover the nutrients present in AnMBR effluent at lab scale. However, up-scaling from controlled lab conditions to varying outdoor conditions could limit the industrial applications of this technology. This study consists of the assessment of a microalgae culture in an MPBR pilot plant fed by effluent of an AnMBR system. For this, optimal operating conditions of the MPBR plant were evaluated, considering both the microalgae biological process and the membrane fouling rate. The effect of other parameters that have an influence on the process such as light intensity applied to the photobioreactors (PBRs), temperature, organic matter concentration, presence of other organisms, etc., was also studied; as well as the specific weight of each parameter on the process. Another goal consisted of finding new controlling parameters that ease the continuous operation of the system. The MPBR system used in this study showed appeared to be capable of treating AnMBR effluent, successfully accomplishing legal discharge limits. However, this was only achieved when the following conditions were reached: i) PBR light path was as narrow as 10 cm. ii) Operating conditions (BRT and HRT) were in the appropriate range. iii) Temperature was under the máximum limit of around 30 ºC. iv) Nitrite was not accumulated. v) Ammonium was the main nitrogen source. vi) Organic matter concentration in the culture was not high.González Camejo, J. (2019). Assessment of the flat-pannel membrane photobioreactor technology for wastewater treatment: Outdoor application to treat the effluent of an anaerobic membrane bioreactor [Tesis doctoral no publicada]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/133056TESISCompendi

Preliminary data set to assess the performance of an outdoor membrane photobioreactor

[EN] This data in brief (DIB) article is related to a Research article entitled 'Optimising an outdoor membrane photobioreactor for tertiary sewage treatment' [1]. Data related to the effect of substrate turbidity, the ammonium concentration at which the culture reaches nitrogen-deplete conditions and the microalgae growth rate under outdoor conditions is provided. Microalgae growth rates under different substrate turbidity were obtained to assess the reduction of the culture's light availability. Lab-scale experiments showed growth rates reductions of 22-44%. Respirometric tests were carried to know the limiting ammonium concentration in thismicroalgae-basedwastewater treatment system. Growth rates (m) of green microalgae Scenedesmus and Chlorella obtained under outdoor conditions; i.e. 0.40 d(-1) (R-2 = 0.993) and 0.43 d(-1) (R-2 = 0.995), respectively, can be useful to obtain optimum operating conditions of membrane photobioreactor (MPBR).This research work 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. It also received support from the Spanish Ministry of Education, Culture and Sport via a pre-doctoral FPU fellowship to the first author (FPU14/05082).Gonzalez-Camejo, J.; Jiménez Benítez, AL.; Ruano, MV.; Robles Martínez, Á.; Barat, R.; Ferrer, J. (2019). Preliminary data set to assess the performance of an outdoor membrane photobioreactor. Data in Brief. 27:1-7. https://doi.org/10.1016/j.dib.2019.104599S172

Plan de actividades deportivas para contribuir al fortalecimiento del valor responsabilidad en los niños de 9-10 años de déisbol del Combinado Deportivo no.1 del municipio Sandino

Esta tesis presenta un plan de actividades deportivas para contribuir al fortalecimiento del valor responsabilidad en los niños de 9 a 10 años de béisbol del combinado deportivo # 1 del municipio Sandino. Se sustenta en fundamentos filosóficos, psicológicos, sociológicos, y pedagógicos. El trabajo es una propuesta dirigida desde la comunidad a fortalecer el valor mencionado, visto desde, la perspectiva de ser mejores ciudadanos, siendo las actividades deportivas un espacio sustancial en la vida de los estudiantes, que se convierten en un multiplicador fundamental en la auto educación y el perfeccionamiento integral. Las actividades deportivas que se proponen fueron evaluadas mediante instrumentos y acciones que midieron cómo se comporta el sujeto desde lo actitudinal y su influencia futura en el mejoramiento social (familia y entorno social). Su significación práctica está dada en que se proporcionan vías y modos de actuación a los estudiantes de la comunidad de forma que generen cambios positivos en ellos y contribuyan al fortalecimiento de los valores para el logro de una cultura de paz en el entorno social en que se desenvuelven los estudiante

Continuous 3-year outdoor operation of a flat-panel membrane photobioreactor to treat effluent from an anaerobic membrane bioreactor

A membrane photobioreactor (MPBR) plant was operated continuously for 3 years to evaluate the separate effects of different factors, including: biomass and hydraulic retention times (BRT, HRT), light path (Lp), nitrification rate (NOxR) and nutrient loading rates (NLR, PLR). The overall effect of all these parameters, which influence MPBR performance had not previously been assessed. The multivariate projection approach chosen for this study provided a good description of the collected data and facilitated their visualization and interpretation. Forty variables used to control and assess MPBR performance were evaluated during three years of continuous outdoor operation by means of principal component analysis (PCA) and partial least squares (PLS) analysis. The PCA identified the photobioreactor light path as the factor with the largest influence on data variability. Other important factors were: air flow rate (Fair), nitrogen and phosphorus recovery rates (NRR, PRR), biomass productivity (BP),optical density at 680 nm (OD680), ammonium and phosphorus effluent concentration (NH4, P), HRT, BRT, and nitrogen and phosphorus loading rates (NLR and PLR). The MPBR performance could be adequately estimated by a PLS model based on all the recorded variables, but this estimation worsened appreciably when only the controllable variables (Lp, Fair, HRT and BRT) were used as predictors, which underlines the importance of the non-controlled variables on MPBR performance. The microalgae cultivation process could thus only be partially controlled by the design and operating variables. As effluent nitrate concentration was shown to be the key factor in the nitrification rate, it can be used as an indirect measurement of nitrifying bacteria activity. A high nitrification rate was found to be inadvisable, since it showed an inverse correlation with NRR. In this respect, temperature appeared to be the main ambient/controlling factor in nitrifying bacteria activity

Production of microalgal external organic matter in a Chlorella-dominated culture: influence of temperature and stress factors

Although microalgae are recognised to release external organic matter (EOM), little is known about this phenomenon in microalgae cultivation systems, especially on a large scale. A study on the effect of microalgae-stressing factors such as temperature, nutrient limitation and ammonium oxidising bacteria (AOB) competition in EOM production by microalgae was carried out. The results showed non-statistically significant differences in EOM production at constant temperatures of 25, 30 and 35 °C. However, when the temperature was raised from 25 to 35 °C for 4 h a day, polysaccharide production increased significantly, indicating microalgae stress. Nutrient limitation also seemed to increase EOM production. No significant differences were found in EOM production under lab conditions when the microalgae competed with AOB for ammonium uptake. However, when the EOM concentration was monitored during continuous outdoor operation of a membrane photobioreactor (MPBR) plant, nitrifying bacteria activity was likely to be responsible for the increase in EOM concentration in the culture. Other factors such as high temperatures, ammonium-depletion and low light intensities could also have induced cell deterioration and thus have influenced EOM production in the outdoor MPBR plant. Membrane fouling seemed to depend on the biomass concentration of the culture. However, under the operating conditions tested, the behaviour of fouling rate with respect to the EOM concentration was different depending on the initial membrane state

Estado del agua y programas de seguimiento. Directiva Europea Marco del Agua.

El artículo aborda la gestión de masas de agua de todos los tipos según establece la Directiva Europea Marco del Agua.Pachés Giner, MAV.; González Camejo, J. (2022). Estado del agua y programas de seguimiento. Directiva Europea Marco del Agua. Universitat Politècnica de València. http://hdl.handle.net/10251/183323DE

Dataset to assess the shadow effect of an outdoor microalgae culture

[EN] This data in brief (DIB) article is related to a Research article [1]. Microalgae biomass absorb the light photons that are supplied to the culture, reducing the light availability in the inner parts of the photobioreactors. This is known as self-shading or shadow effect. This effect has been widely studied in lab conditions, but information about self-shading in outdoor photobioreactors is scarce. How this shadow effect affects the light availability in an outdoor photobioreactor was evaluated. In addition, advantages and disadvantages of different artificial light sources which can overcome light limitation are described.This research work 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), 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 J. Gonzalez-Camejo (FPU14/05082).Gonzalez-Camejo, J.; Viruela, A.; Ruano, MV.; Barat, R.; Seco, A.; Ferrer, J. (2019). Dataset to assess the shadow effect of an outdoor microalgae culture. Data in Brief. 25:1-4. https://doi.org/10.1016/j.dib.2019.104143S142

Nitrite inhibition of microalgae induced by the competition between microalgae and nitrifying bacteria

Outdoor microalgae cultivation systems treating anaerobic membrane bioreactor (AnMBR) effluents usually present ammonium oxidising bacteria (AOB) competition with microalgae for ammonium uptake, which can cause nitrite accumulation. In literature, nitrite effects over microalgae have shown controversial results. The present study evaluates the nitrite inhibition role in a microalgae-nitrifying bacteria culture. For this purpose, pilot- and lab-scale assays were carried out. During the continuous outdoor operation of the membrane photobioreactor (MPBR) plant, biomass retention time (BRT) of 2 d favoured AOB activity, which caused nitrite accumulation. This nitrite was confirmed to inhibit microalgae performance. Specifically, continuous 5-d lab-scale assays showed a reduction in the nitrogen recovery efficiency by 32, 42 and 80% when nitrite concentration in the culture accounted for 5, 10 and 20 mg N·L−1, respectively. On the contrary, short 30-min exposure to nitrite showed no significant differences in the photosynthetic activity of microalgae under nitrite concentrations of 0, 5, 10 and 20 mg N·L−1. On the other hand, when the MPBR plant was operated at 2.5-d BRT, the nitrite concentration was reduced to negligible values due to increasing activity of microalgae and nitrite oxidising bacteria (NOB). This allowed obtaining maximum MPBR performance; i.e. nitrogen recovery rate (NRR) and biomass productivity of 19.7 ± 3.3 mg N·L−1·d−1 and 139 ± 35 mg VSS·L−1·d−1, respectively; while nitrification rate (NOxR) reached the lowest value (13.5 ± 3.4 mg N·L−1·d−1). Long BRT of 4.5 d favoured NOB growth, avoiding nitrite inhibition. However, it implied a decrease in microalgae growth and the accumulation of nitrate in the MPBR effluent. Hence, it seems that optimum BRT has to be within the range 2-4.5 d in order to favour microalgae growth with respect to AOB and NOB

Optimising an outdoor membrane photobioreactor for tertiary sewage treatment

The operation of an outdoor membrane photobioreactor plant which treated the effluent of an anaerobic membrane bioreactor was optimised. Biomass retention times of 4.5, 6, and 9 days were tested. At a biomass retention time of 4.5 days, maximum nitrogen recovery rate:light irradiance ratios, photosynthetic efficiencies and carbon biofixations of 51.7 ± 14.3 mg N·mol−1, 4.4 ± 1.6% and 0.50 ± 0.05 kg CO2·m3influent, respectively, were attained. Minimum membrane fouling rates were achieved when operating at the shortest biomass retention time because of the lower solid concentration and the negligible amount of cyanobacteria and protozoa. Hydraulic retention times of 3.5, 2, and 1.5 days were tested at the optimum biomass retention times of 4.5 days under non-nutrient limited conditions, showing no significant differences in the nutrient recovery rates, photosynthetic efficiencies and membrane fouling rates. However, nitrogen recovery rate:light irradiance ratios and photosynthetic efficiency significantly decreased when hydraulic retention time was further shortened to 1 day, probably due to a rise in the substrate turbidity which reduced the light availability in the culture. Optimal carbon biofixations and theoretical energy recoveries from the biomass were obtained at hydraulic retention time of 3.5 days, which accounted for 0.55 ± 0.05 kg CO2·m−3influent and 0.443 ± 0.103 kWh·m−3influent, respectively

The shared management as strategy for food and nutrition security : the cases of Costa Rica and Brazil

Considerando as transformações na governança do Estado e a importância da participação social na formulação de estratégias alternativas para alcançar a Segurança Alimentar e Nutricional (SAN) das comunidades, infere-se a importância de estratégias em SAN a partir de abordagens de gestão compartilhada. Esta gestão precisa integrar as organizações estatais e as organizações da sociedade civil. Este estudo tem por objetivo abordar a importância da gestão compartilhada das políticas como uma estratégia para o alcance da SAN. A partir de pesquisa documental e consulta à base de dados, trazem-se os casos da Costa Rica e do Brasil, nos quais suas políticas sugerem a participação efetiva da sociedade tanto para planejamento quanto para execução das ações. Conclui-se que a diferença entre a Costa Rica e o Brasil está no fato de que este último inicia suas ações na temática a partir dos movimentos sociais que vão permeando as estruturas políticas, até gerar um marco legal e institucional para a gestão compartilhada. No caso da Costa Rica, as políticas foram de iniciativa do Estado. Em ambos os países, a participação social tem sido considerada fundamental para a consolidação das estratégias de SAN.Considering the changes in the governance of the state and the importance of social participation in demand for alternative strategies to achieve food and nutrition security (SAN) communities, infers the importance of strategies in SAN starting from shared management approaches. This management needs to integrate governmental organizations and civil society organizations. This study aims to demonstrate the importance of sharing management policies as a strategy for achieving SAN. As from documentary research and consultation to the databases, demonstrate the cases of Costa Rica and Brazil, where its policies suggest effective participation in society as planning as execution of actions. We conclude that the difference between Costa Rica and Brazil is that the Brazil starts the actions from the social movements that will permeate the political structures to create a legal and institutional framework for the shared management. In Costa Rica policies were initiated by the State. Both countries social participation has been considered essential for the consolidation of strategies