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El presente libro tiene como objetivo general conocer los fundamentos y la aplicación de las tecnologías disponibles para el tratamiento bilógico de las aguas residuales. Este libro pretende dotar a estudiantes, profesionales o investigadores de los conocimientos y habilidades necesarias para el pre-diseño de diferentes sistemas de tratamiento bilógico de las aguas residuales y de los fangos producidos en el proceso. Para ello, se profundiza en el estudio de los procesos biológicos, cuyo uso generalizado en la depuración de aguas residuales urbanas y gran número de industriales, por una parte, y su gran complejidad, por otra, justifica la importancia de un estudio detallado de los mismos. Asimismo, se tratan aspectos fundamentales referentes a la microbiología de los procesos, la cinética y la estequiometría de las reacciones bioquímicas, tipos de procesos, esquemas de proceso, aplicabilidad, etc. Además, se aborda la problemática de la producción de fangos, así como el diseño de los distintos métodos de tratamiento existentes.

[EN] Nutrient recovery technologies are rapidly expanding due to the need for the appropriate recycling of key elements from waste resources in order to move towards a truly sustainable modern society based on the Circular Economy. Nutrient recycling is a promising strategy for reducing the depletion of non-renewable resources and the environmental impact linked to their extraction and manufacture. However, nutrient recovery technologies are not yet fully mature, as further research is needed to optimize process efficiency and enhance their commercial applicability. This paper reviews state-of-the-art of nutrient recovery, focusing on frontier technological advances and economic and environmental innovation perspectives. The potentials and limitations of different technologies are discussed, covering systems based on membranes, photosynthesis, crystallization and other physical and biological nutrient recovery systems (e.g. incineration, composting, stripping and absorption and enhanced biological phosphorus recovery).

[EN] The potential of microbial communities for efficient anaerobic conversion of raw microalgae was evaluated in this work. A long-term operated thermophilic digester was fed with three different Organic Loading Rates (OLR) (0.2, 0.3 and 0.4¿g·L¿1·d¿1) reaching 32¿41% biodegradability values. The microbial community analysis revealed a remarkable presence of microorganisms that exhibit high hydrolytic capabilities such as Thermotogae (~44.5%), Firmicutes (~17.6%) and Dictyoglomi, Aminicenantes, Atribacteria and Planctomycetes (below ~5.5%) phyla. The suggested metabolic role of these phyla highlights the importance of protein hydrolysis and fermentation when only degrading microalgae. The ecological analysis of the reactor suggests the implication of the novel group EM3 in fermentation and beta-oxidation pathways during microalgae conversion into methane. Scenedesmus spp. substrate and free ammonia concentration strongly shaped thermophilic reactor microbial structure. Partial Least Square Discriminant Analysis (PLS-DA) remarked the resilient role of minor groups related to Thermogutta, Armatimonadetes and Ruminococcaceae against a potential inhibitor like free ammonia. Towards low-cost biogas production from microalgae, this study reveals valuable information about thermophilic microorganisms that can strongly disrupt microalgae and remain in high solids retention anaerobic digesters.

[EN] Ruminal fluid was inoculated in an Anaerobic Membrane Reactor (AnMBR) to produce biogas from raw Scenedesmus. This work explores the microbial ecology of the system during stable operation at different solids retention times (SRT). The 16S rRNA amplicon analysis revealed that the acclimatised community was mainly composed of Anaerolineaceae, Spirochaetaceae, Lentimicrobiaceae and Cloacimonetes fermentative and hydrolytic members. During the highest biodegradability achieved in the AnMBR (62%) the dominant microorganisms were Fervidobacterium and Methanosaeta. Different microbial community clusters were observed at different SRT conditions. Interestingly, syntrophic bacteria Gelria and Smithella were enhanced after increasing 2-fold the organic loading rate, suggesting their importance in continuous systems producing biogas from raw microalgae.

[EN] The sedimentability of the activated sludge can be affected by the presence of a large variety of coagulants and polymers from a previous physical-chemical process. In this paper, the activated sludge settling process in industrial wastewater treatment plants where the sludge does not settle in a conventional way is studied. The two observed constant hindered settling velocity stages and the instant the intermediate sludge acceleration period occurs are described. A variation of the Richardson and Zaki model is used to characterize the two stages of constant settling velocity. The concentration of suspended solids, where a sudden decrease of hindered settling velocity was observed, is calculated. Finally, a new hypothesis to explain the processes triggering the collapse of the initial homogeneous sludge structure and the existence of an acceleration period is formulated.

[EN] A series of eight experiments were carried out to analyse the effects of light intensity, light duration and photoperiods on a microalgae culture for treating AnMBR effluent at an outdoor photobioreactor (PBR) plant. Improved performance was achieved in terms of nutrient recovery rates, biomass productivity and effluent nutrient concentrations at a higher net photon flux. However, the higher irradiance was also responsible for lower biomass productivity:light irradiance ratios. None of the experiments with different lighting regimes and the same net photon flux showed any significant differences. The data obtained suggest that microalgae performance in this system did not depend on the time of day when light was applied or the length of the photoperiods, but on the net photon flux. No photoinhibiton was observed in any of the experiments, probably because of the significant shadow effect on the microalgae in the PBRs.

[EN] Practical recovery of a non-renewable nutrient, such as phosphorus (P), is essential to support modern agriculture in the near future. The high P content of urine, makes it an attractive source for practicing the recovery of this crucial nutrient. This paper presents the experimental results at pilot-plant scale of struvite crystallisation from a source-separated urine stream using two different magnesium sources, namely magnesium chloride and seawater. The latter was chosen as sustainable option to perform P-recovery in coastal areas. Real seawater was used to assess in a more realistic way its efficiency to precipitate P as struvite, since its composition (with noticeable concentration of ions such as Ca2+, SO42¿, Na+, ¿) could lead to the formation of impurities and other precipitates. 0.99¿g of struvite was obtained per litre of urine irrespective of the operational conditions tested. In all tested conditions, precipitation efficiencies exceeded 90% and recovery efficiencies were higher than 87%, with an average struvite crystal size higher than 110¿¿m (and up to 320¿¿m, depending on the experimental conditions) in the harvested struvite samples. Almost pure struvite was obtained when MgCl2 was used as precipitant, while amorphous calcium phosphate and other impurities appeared in the precipitates using seawater as magnesium source. However, the lower settling velocity of the amorphous precipitates in comparison with the struvite precipitates suggests that their separation at industrial scale could be relatively straightforward.

[EN] In the present study, the effect of cross-flow filtration (CFF) on the overall valorization of Chlorella spp. microalgae as biogas was assessed. The effect of CFF on microalgae cell integrity was quantified in terms of viability which was correlated with the anaerobic biodegradability. The viability dropped as the biomass concentration increased, whereas anaerobic biodegradability increased linearly with the viability reduction. It was hypothesized that a stress-induced release and further accumulation of organic polymers during CFF increased the flux resistance which promoted harsher shear-stress conditions. Furthermore, the volume reduction as the concentration increased entailed an increase in the specific energy supply to the biomass. The energy demand was positive in the whole range of concentrations studied, yielding an overall energy efficiency as high as 22.9% for the highest concentration studied. Specifically, heat requirements were lower than electricity requirements only when the biomass concentrations exceeded 10 g COD.L-1.

El presente libro tiene como objetivo general conocer los fundamentos y la aplicación de las tecnologías disponibles para el tratamiento bilógico de las aguas residuales. Este libro pretende dotar a estudiantes, profesionales o investigadores de los conocimientos y habilidades necesarias para el pre-diseño de diferentes sistemas de tratamiento bilógico de las aguas residuales y de los fangos producidos en el proceso. Para ello, se profundiza en el estudio de los procesos biológicos, cuyo uso generalizado en la depuración de aguas residuales urbanas y gran número de industriales, por una parte, y su gran complejidad, por otra, justifica la importancia de un estudio detallado de los mismos.Asimismo, se tratan aspectos fundamentales referentes a la microbiología de los procesos, la cinética y la estequiometría de las reacciones bioquímicas, tipos de procesos, esquemas de proceso, aplicabilidad, etc.Además,se aborda la problemática de la producción de fangos, así como el diseño de los distintos métodos de tratamiento existentes.

[EN] Anaerobic membrane bioreactors (AnMBRs) can achieve maximum energy recovery from urban wastewater (UWW) by converting influent COD into methane. The aim of this study was to assess the anaerobic biodegradability limits of urban wastewater with AnMBR technology by studying the possible degradation of the organic matter considered as non-biodegradable as observed in aerobic membrane bioreactors operated at very high sludge retention times. For this, the results obtained in an AnMBR pilot plant operated at very high SRT (140 days) treating sulfate-rich urban wastewater were compared with those previously obtained with the system operating at lower SRT (29 to 70 days). At 140 days SRT the organic matter biodegraded by the AnMBR system accounted for 64.4% of the influent COD (45.9% was removed by sulfate reducing bacteria (SRB), and only 18.5% was converted into methane, highlighting the strong competition between SRB and methanogenic archaea (MA) when treating sulfate-rich wastewater). Almost half of the methane produced (46%) was dissolved in the permeate and most of it was recovered by a degassing membrane. The organic matter biodegraded by the AnMBR system was similar to the influent anaerobic biodegradability determined by wastewater characterization assays (68.5% of the influent COD), indicating that nearly all the influent's biodegradable organic matter had been removed. This percentage of degraded COD was similar to that obtained in previous studies working at 70 days SRT, showing that the limit of anaerobic biodegradability was already reached in this SRT. The organic matter considered as non-biodegradable according to wastewater characterization assays therefore was not seen to degrade in the AnMBR pilot plant, even at very high SRT. Once the biodegraded COD is close to the influent's anaerobic biodegradability, increasing the SRT is not justified as it only leads to higher operational costs for the same biogas production. These findings support the use of

[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).

[EN] The use of anaerobic membrane bioreactor technology (AnMBR) is rapidly expanding. However, depending on the application, AnMBR design and operation is not fully mature, and needs further research to optimize process efficiency and enhance applicability. This paper reviews state-of-the-art of AnMBR focusing on modelling and control aspects. Quantitative environmental and economic evaluation has demonstrated substantial advantages in application of AnMBR to domestic wastewater treatment, but detailed modelling is less mature. While anaerobic process modelling is generally mature, more work is needed on integrated models which include coupling between membrane performance (including fouling) and the biological process. This should include microbial factors, which are important to generation of specific foulants such as soluble and particulate inert organics. Mature and well-established control tools, including better feedback control strategies are also required for both the process, and for fouling control.

[EN] The objective of this work was to evaluate the performance of a pilot scale membrane photobioreactor (MPBR) for treating the effluent of an anaerobic membrane bioreactor (AnMBR) system. In particular, new experimental data on microalgae productivity, nutrient recovery, CO2 biofixation and energy recovery potential was obtained under different operating conditions, which would facilitate moving towards cost-effective microalgae cultivation on wastewater. To this aim, a 2.2-m(3) MPBR equipped with two commercial-scale hollow-fibre ultrafiltration membrane modules was operated treating the nutrient-loaded effluent from an AnMBR for sewage treatment. The influence of several design, environmental and operating parameters on MPBR performance was studied. Among the conditions evaluated, variations in solar irradiance significantly affected the nutrient recovery rate (NRR). Operating at temperatures above 25 degrees C and high biomass concentrations, which increased light shading effect, negatively affected biomass production and NRR. Maximum biomass productivity of 66 mg VSS L-1 d(-1) (areal productivity of 15.78 g VSS m(-2) d(-1)) and NRR of 7.68 mg N L-1 d(-1) and 1.17 mg P L-1 d(-1) were achieved when operating at 4.5 days of biomass retention time. These results would outcome maximum theoretical energy recoveries and CO2 biofixations of about 0.43 kWh and 0.51 kg CO2 per m(3) of treated water, respectively. Moreover, the excellent quality permeate that was produced (i.e. negligible levels of pathogens and suspended solids) represents a reclaimed water source. (C) 2017 Elsevier Ltd. All rights reserved.

[EN] This paper describes a study carried out to determine the removal kinetics of four micropollutants (4-tert-octylphenol (OP), technical-nonylphenol (t-NP), 4-nonylphenol (4-NP) and bisphenol-A (BPA)) usually found in wastewater streams. The kinetic experiments were carried out in batch reactors containing the effluent of an Anaerobic Membrane BioReactor (AnMBR) in the presence of light, oxygen and microalgae. As the degradation process of the studied micropollutants obeyed a pseudo-first-order kinetics, the second-order kinetics for each micropollutant was then calculated. The second order rate constants for the hydroxyl radical (k.(OH)) ranged from 7.0.10(+10) to 6.6.10(+12) L.mol(-1).min(-1) and for the oxygen (k(O2)) from 77 to 125 L.mol(-1).min(-1). The k(O2) values were significantly lower than the k% OH values, indicating that the hydroxyl radical is a better oxidising agent than oxygen. However, as the concentration of dissolved oxygen was higher than that of the hydroxyl radical, higher oxygen pseudo-first order rate constants were produced (k(O2), ranging from 0.016 to 0.026 min(-1)) than hydroxyl radical pseudo-first order rate constants (k.(OH), ranging from 7.0.10-05 to 6.6.10-03 min(-1)), bringing the degradation process under the control of the oxygen mechanism. The proposed kinetic model was validated by fitting experimental data from a study of supersaturated oxygen concentration and showed good correlation for all the studied micropollutants.

[EN] Anaerobic digestion of indigenous Scenedesmus spp. microalgae was studied in continuous lab-scale anaerobic reactors at different temperatures (35 degrees C and 55 degrees C), and sludge retention time - SRT (50 and 70 days). Mesophilic digestion was performed in a continuous stirred-tank reactor (CSTR) and in an anaerobic membrane bioreactor (AnMBR). Mesophilic CSTR operated at 50 days SRT only achieved 11.9% of anaerobic biodegradability whereas in the AnMBR at 70 days SRT and 50 days HRT reached 39.5%, which is even higher than the biodegradability achieved in the thermophilic CSTR at 50 days SRT (30.4%). Microbial analysis revealed a high abundance of cellulose-degraders in both reactors, AnMBR (mainly composed of 9.4% Bacteroidetes, 10.1% Chloroflexi, 8.0% Firmicutes and 13.2% Thermotogae) and thermophilic CSTR (dominated by 23.8% Chloroflexi and 12.9% Firmicutes). However, higher microbial diversity was found in the AnMBR compared to the thermophilic CSTR which is related to the SRT. since high SRT promoted low growth-rate microorganisms, increasing the hydrolytic potential of the system. These results present the membrane technology as a promising approach to revalue microalgal biomass, suggesting that microalgae biodegradability and consequently the methane production could be improved operating at higher SRT. (C) 2018 Elsevier Ltd. All rights reserved.

[EN] As microalgae have the ability to simultaneously remove nutrients from wastewater streams while producing valuable biomass, microalgae-based wastewater treatment is a win-win strategy. Although recent advances have been made in this field in lab conditions, the transition to outdoor conditions on an industrial scale must be further investigated. In this work an outdoor pilot-scale membrane photobioreactor plant was operated for tertiary sewage treatment. The effects of different parameters on microalgae performance were studied including: temperature, light irradiance (solar and artificial irradiance), hydraulic retention time (HRT), biomass retention time (BRT), air sparging system and influent nutrient concentration. In addition the competition between microalgae and ammonium oxidising bacteria for ammonium was also evaluated. Maximum nitrogen and phosphorus removal rates of 12.5 +/- 4.2 mgN.L-1.d(-1) and 1.5 +/- 0.4 mgP.L-1.d(-1), respectively, were achieved at a BRT of 4.5 days and HRT of 2.5 days, while a maximum biomass productivity of 78 +/- 13 mgVSS.L-1.d(-1 )(VSS: volatile suspended solids) was reached. While the results obtained so far are promising, they need to be improved to make the transition to industrial scale operations feasible.

[EN] Notorious changes in microbial communities were observed during and after the joint treatment of wastewater with Food Waste (FW) in an Anaerobic Membrane Bioreactor (AnMBR) plant. The microbial population was analysed by high-throughput sequencing of the 16S rRNA gene and dominance of Chloroflexi, Firmicutes, Synergistetes and Proteobacteria phyla was found. The relative abundance of these potential hydrolytic phyla increased as a higher fraction of FW was jointly treated. Moreover, whereas Specific Methanogenic Activity (SMA) rose from 10 to 51 mL CH4 g(-1) VS, Methanosarcinales order increased from 34.0% over 80.0% of total Archaea, being Methanosaeta the dominant genus. The effect of FW over AnMBR biomass was observed during the whole experience, as methane production rose from 49.2 to 144.5 L CH4 . kg(-1) influent COD. Furthermore, biomethanization potential was increased over 82% after the experience. AnMBR technology allows the established microbial community to remain in the bioreactor even after the addition of FW, improving the anaerobic digestion of urban wastewater. (C) 2018 Elsevier Ltd. All rights reserved.

[EN] Spectroscopy technology and statistical methods (Partial Least Squares) have been integrated to develop a model that allows estimating the microalgal biomass in a photobioreactor. The model employing PLS combines the absorption spectrum measurements in the visible range (400-750 nm) with a microalgae cell density in a water sample. First, a calibration model was constructed using a calibration data set, and then, the predictive capacity of the model was determined by cross validation. Finally, an external validation of the predictive performance of the model was carried out with an independent data set. To test the accuracy of the model it was applied to different culture conditions yielding a predictive capacity of 96.7 %. The results achieved are highly satisfactory due to the good lineal adjustment between observed cell densities vs. predicted ones obtained. According to the results obtained, the application of the model is a useful tool for the management and the decision-making process when operating a photobioreactor. Moreover, this model may boost the real-time measurements and may represent a previous step for further technical development in the ¿internet of things¿ applied to the management of the photobioreactor.

[ES] El tratamiento actual de depuración implantado en la mayoría de las depuradoras considera el agua residual como un residuo a gestionar y no como una fuente de recursos que se puedan recuperar. Sin embargo, motivado por un incremento en la sensibilización ambiental y el desarrollo de la legislación ambiental, el estudio de la depuración de las aguas residuales se está centrando en lograr convertir las estaciones depuradoras de agua residual en estaciones de recuperación de recursos. Esta transformación acerca el campo de la depuración del agua residual urbana hacia un tratamiento sostenible que permita llevar a cabo una economía circular, al poder aprovechar los ahora llamados residuos, como fuente de recursos. Uno de los actuales objetivos que se desea alcanzar para una estación de recuperación de recursos, es lograr obtener la mayor valorización energética posible. Esto consiste fundamentalmente en incrementar el papel de los procesos anaerobios en la depuración, sustituyendo a los aerobios. De esta manera se incrementa la cantidad de biogás producido a la vez que se reducen las necesidades energéticas. Una de las maneras de conseguir potenciar el tratamiento anaerobio consiste en el empleo de membranas de filtración como etapa previa al tratamiento biológico. Mediante la filtración se logra destinar la mayor parte de la DQO de entrada (toda la fracción suspendida y parte de la soluble) al digestor anaerobio, para su posterior valorización energética. La corriente de agua que no es retenida en la membrana, el permeado, es llevada al tratamiento biológico (de acuerdo a los requisitos de vertido). Al estar formada esta corriente tan solo por parte de los contaminantes solubles, se consigue incrementar la capacidad de tratamiento del reactor biológico. Esto es posible reduciendo el tiempo de retención hidráulico de operación (y con ello el volumen del reactor) e incrementando el tiempo de retención celular, al haber una menor concentración de sólidos, para asegur, [CA] El tractament actual de depuració implantat en la majoria de les depuradores considera l'aigua residual com un residu a gestionar i no com una font de recursos que es puguen recuperar. No obstant això, motivat per un increment en la sensibilització ambiental i el desenrotllament de la legislació ambiental, l'estudi de la depuració de les aigües residuals s'està centrant a aconseguir convertir les estacions depuradores d'aigua residual en estacions de recuperació de recursos. Esta transformació acosta el camp de la depuració de l'aigua residual urbana cap a un tractament sostenible que permeta dur a terme una economia circular, al poder aprofitar els ara cridats residus, com a font de recursos. Un dels actuals objectius que es desitja aconseguir per a una estació de recuperació de recursos, és aconseguir obtindre la major valoració energètica possible. Açò consistix fonamentalment a incrementar el paper dels processos anaerobis en la depuració, substituint als aerobis. D'esta manera s'incrementa la quantitat de biogàs produït al mateix temps que es reduïxen les necessitats energètiques. Una de les maneres d'aconseguir potenciar el tractament anaerobi consistix en l'ús de membranes de filtració com a etapa prèvia al tractament biològic. Per mitjà de la filtració s'aconseguix destinar la major part de la DQO d'entrada (tota la fracció suspesa i part de la soluble) al digestor anaerobi, per a la seua posterior valoració energética. El corrent d'aigua que no és retinguda en la membrana, el permeado, és portada al tractament biològic (d'acord amb els requisits d'abocament). A l'estar formada este corrent tan sols per part dels contaminants solubles, s'aconseguix incrementar la capacitat de tractament del reactor biològic. Açò és possible reduint el temps de retenció hidràulic d'operació (i amb això el volum del reactor) i incrementant el temps de retenció cel·lular, a l'haver-hi una menor concentració de sòlids, per a assegurar l'eliminació de nitrogen i inclús incre, [EN] The current wastewater treatment consider wastewater as a waste which need to be managed in stead of consider wastewater as a raw material for obtaining very useful resources. However, due to the increase of environmental awareness and the develop of environmental legislation, the study of wastewater has focused on transformation of wastewater treatment plants in resource recovery facilities. This change is a step further in the paradigm shift in the field of urban wastewater treatment towards a sustainable treatment and circular economy that be able to use wastewater as a source of resources One of the aims of a resource recovery facilities is to increase the percentage of organic matter that can be valorize in anaerobic digestion. By replacing the aerobic processes to anaerobic processes, its possible to enhance valorization of organic matter at the same that time requirement energetic is reduced. One of the ways to improve the anaerobic digestión is the use of membrane filtration like a pre-treatment of biological treatment. The membrane filtration process will allow the recovery of all suspended organic matter and part of the organic matter soluble in anaerobic digestión, treating in the process of activated sludge only a part of the soluble fraction of the contaminants. In this way the activated sludge process can be operated with low hydraulic retention times (reduced volumes) and high sludgel retention times (necessary to ensure the removal of nitrogen if necessary and increase the removal of priority substances). Another important advantages of membrane filtration process is the easy implementation of this technology, because does not require deep changes on the current treatment train. Furthermore, membrane technology taking advantage of existing infrastructures. The few studies on direct filtration of wastewater focus on the filtration process to determine optimal operating conditions. This Master¿¿s thesis look for to complement that information with

[EN] The occurrence and fate of three groups of micropollutants - alkylphenols, pentachlorophenol and hormones - were studied in a pilot plant consisting of an anaerobic membrane bioreactor (AnMBR) coupled to an activated sludge reactor (University of Cape Town configuration - UCT). Under anaerobic conditions, the octylphenol and technical-nonylphenol soluble concentrations increased producing negative degradation ratios (i.e., -175 and -118%, respectively). However, high 4-n-nonylphenol and bisphenol-A degradation ratios (92 and 59% for 4-n-nonylphenol and bisphenol-A, respectively) as well as complete pentachlorophenol, estrone, 17 beta-estradiol and 17 alpha-ethinylestradiol removal were observed. Under aerobic conditions (UCT), octylphenol, technical-nonylphenol, 4-n-nonylphenol and bisphenol-A degradation ratios were higher than 84%. The AnMBR thus removes a high proportion of 4-n-nonylphenol, pentachlorophenol, estrone, 17 beta-estradiol and 17 alpha-ethinylestradiol, but requires a later post-treatment process (such as UCT) to improve bisphenol-A, octylphenol and technical-nonylphenol degradation ratios. The overall AnMBR-UCT degradation ratios were 48% and 70% for octylphenol and technical-nonylphenol, respectively, and higher than 97% for 4-n-nonylphenol and bisphenol-A. The AnMBR produced a higher micropollutant accumulation in the sludge than the UCT: removal by adsorption in the AnMBR process was between 0.5 and 10%, and less than 0.5% in the UCT process. The combination of AnMBR and UCT technologies produces an effluent stream with low concentrations of micropollutants.

[EN] Conventional treatments for nutrient removal in wastewater are shifting to Anaerobic Membrane Bioreactors, which produce a high-quality effluent with minimum sludge production. The effluent resulting contains high nitrogen and phosphorus load that can be eliminated by microalgae culture. The aim of this study is to evaluate the ammonium and phosphorus removal rate of different microalgae species in the effluent of an anaerobic treatment. For that, 4 different microalgae species have been tested (Chlamydomonas reinhardtii, Scenedesmus obliquus, Chlorella vulgaris and Monoraphidium braunii) in batch monoculture and mixed conditions. Results indicate that all species are able to eliminate both P and N in the medium with high removal rates. However a slight interspecies competition may boost these removal rates and productivity values ensuring, the success of the process.

[EN] The aim of this study was to evaluate the effect of light intensity and temperature on nutrient removal and biomass productivity in a microalgae¿bacteria culture and their effects on the microalgae¿bacteria competition. Three experiments were carried out at constant temperature and various light intensities: 40, 85 and 125¿µE¿m¿2¿s¿1. Other two experiments were carried out at variable temperatures: 23¿±¿2°C and 28¿±¿2°C at light intensity of 85 and 125¿µE¿m¿2¿s¿1, respectively. The photobioreactor was fed by the effluent from an anaerobic membrane bioreactor. High nitrogen and phosphorus removal efficiencies (about 99%) were achieved under the following operating conditions: 85¿125¿µE¿m¿2¿s¿1 and 22¿±¿1°C. In the microalgae¿bacteria culture studied, increasing light intensity favoured microalgae growth and limited the nitrification process. However, a non-graduated temperature increase (up to 32°C) under the light intensities studied caused the proliferation of nitrifying bacteria and the nitrite and nitrate accumulation. Hence, light intensity and temperature are key parameters in the control of the microalgae¿bacteria competition. Biomass productivity significantly increased with light intensity, reaching 50.5¿±¿9.6, 80.3¿±¿6.5 and 94.3¿±¿7.9¿mgVSS¿L¿1¿d¿1 for a light intensity of 40, 85 and 125¿µE¿m¿2¿s¿1, respectively

[EN] This study describes a model-based method for real-time optimization of the key filtration parameters in a submerged anaerobic membrane bioreactor (AnMBR) treating urban wastewater (UWW) and UWW mixed with domestic food waste (FW). The method consists of an initial screening to find out adequate filtration conditions and a real-time optimizer applied to a periodically calibrated filtration model for minimizing the operating costs. The initial screening consists of two statistical analyses: (1) Morris screening method to identify the key filtration parameters; (2) Monte Carlo method to establish suitable initial control inputs values. The operating filtration cost after implementing the control methodology was (sic)0.047 per m(3) (59.6% corresponding to energy costs) when treating UWW and 0.067 per m(3) when adding FW due to higher fouling rates. However, FW increased the biogas productivities, reducing the total costs to (sic)0.035 per m(3). Average downtimes for reversible fouling removal of 0.4% and 1.6% were obtained, respectively. The results confirm the capability of the proposed control system for optimizing the AnMBR performance when treating both substrates. (C) 2018 Elsevier Ltd. All rights reserved.

[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.

[EN] Microalgae cultivation appears to be a promising technology for treating nutrient-rich effluents from anaerobic membrane bioreactors, as microalgae are able to consume nutrients from sewage without an organic carbon source, although the sulphide formed during the anaerobic treatment does have negative effects on microalgae growth. Short and long-term experiments were carried out on the effects of sulphide on a mixed microalgae culture. The short-term experiments showed that the oxygen production rate (OPR) dropped as sulphide concentration increased: a concentration of 5 mg S L¿1 reduced OPR by 43%, while a concentration of 50 mg S L¿1 came close to completely inhibiting microalgae growth. The long-term experiments revealed that the presence of sulphide in the influent had inhibitory effects at sulphide concentrations above 20 mg S L¿1 in the culture, but not at concentrations below 5 mg S L¿1. These conditions favoured Chlorella growth over that of Scenedesmus.

[EN] Interest in phosphorus (P) recovery and reuse has increased in recent years as supplies of P are declining. After use, most of the P remains in wastewater, making Wastewater Treatment Plants (WWTPs) a vital part of P recycling. In this work, a new sludge management operation was studied by modeling in order to recover Pin the form of struvite and minimize operating problems due to uncontrolled P precipitation in WWTPs. During the study, intensive analytical campaigns were carried out on the water and sludge lines. The results identified the anaerobic digester as a "hot spot" of uncontrolled P precipitation (9.5 gP/kg sludge) and highlighted possible operating problems due to the accumulation of precipitates. A new sludge line management strategy was simulated therefore using DESASS (c) software, consisting of the elutriation of the mixed sludge in the mixing chamber, to reduce uncontrolled P precipitation and to obtain a P-rich stream (primary thickener supernatant) to be used in a crystallization process. The key operating parameters were found to be: the elutriation flow from the mixing chamber to the primary thickener, the digestion flow and the sludge blanket height of the primary thickener, with optimized values between 70 and 80 m(3)/d, 90-100 m(3)/d and 1.4-1.5 m, respectively. Under these operating conditions, the preliminary results showed that P concentration in the primary thickener overflow significantly increased (from 38 to 100 mg PO4-P/L), which shows that this stream is suitable for use in a subsequent crystallization reactor to recover P in the form of struvite. (C) 2017 Elsevier Ltd. All rights reserved.

[EN] Microbial communities were thoroughly characterized in a mesophilic anaerobic membrane bioreactor (AnMBR) and a thermophilic continuous stirred tank reactor (CSTR), which were both treating recalcitrant microalgal biomass dominated by Scenedesmus. 16S rRNA amplicon sequencing analysis was performed when the AnMBR achieved 70% algal biodegradation and revealed high microbial diversity, probably due to the high solid retention time (SRT) of the AnMBR configuration. The bacterial community consisted of Chloroflexi (27.9%), WWE1 (19.0%) and Proteobacteria (15.4%) as the major phyla, followed by Spirochaetes (7.7%), Bacteroidetes (5.9%) and Firmicutes (3.6%). These phyla are known to exhibit proteolytic and cellulolytic capabilities required to degrade the Scenedesmus cell-wall. Methanosaeta was the most abundant methanogen detected in the AnMBR suggesting that methane was mainly produced by the acetoclastic pathway. In comparison, the thermophilic CSTR achieved 32.6% algal biodegradation, and its bacterial community had fewer Operational Taxonomic Units (977 OTUs) than the AnMBR (1396 OTUs), as is generally observed for high temperature biogas reactors. However, phyla with high hydrolytic potential were detected such as Firmicutes (34.6%) and the candidate taxon EM3 (38.7%) in the thermophilic CSTR. Although the functional metabolism of EM3 in anaerobic digesters is unknown, the high abundance of EM3 suggests that this taxon plays an important role in the thermophilic, anaerobic degradation of Scenedesmus. The abundant syntrophic bacteria and the detection of hydrogenotrophic methanogens in the thermophilic CSTR suggest that the hydrogenotrophic pathway was the dominant pathway for methane production in this reactor.

[ES] El aumento de la población a nivel mundial trae consigo un consumo de recursos disponibles por encima de las posibilidades de cada país. Es por ello que con el paso del tiempo se ha visto necesaria la implicación de cada país con el objetivo de gestionar de la mejor manera posible el consumo de dichos recursos. Uno de los problemas más importantes es la necesidad de tratar el agua residual procedente de los núcleos urbanos e industriales, con el fin de dar una calidad adecuada a la misma con anterioridad a ser vertida al cauce público. Los sistemas de control en las estaciones de depuración de aguas residuales (EDAR) desempeñan un papel importante ya que el agua residual afluente presenta una variabilidad en cuanto a composición, caudal y carga contaminante, es por esta razón que en la actualidad ha despertado un gran interés. En el presente trabajo se estudia el comportamiento de una EDAR basada en el esquema de tratamiento Bardenpho modificado. Además, se utiliza el modelo BSM1 (Del inglés: Benchmarck Simulation Model Nº1) para estudiar el efecto de la dinámica del afluente sobre el proceso y el modelo BNRM2 (Del inglés: Biological Nutrient Removal Model Nº2) para simular el esquema de tratamiento. Mediante el software DESASS, se ha implementado la EDAR estudio. Se ha implementado, calibrado y validado un sistema de control mediante el software LoDif BioControl, con el objetivo de optimizar el proceso de eliminación biológica de nitrógeno, mediante un controlador de aireación basado en sonda de amonio ABAC (Del Inglés: Ammonia - Based Aeration Control)., [CA] L'aument de la població a nivell mundial porta en si un consum de recursos disponibles per damunt de les possibilitats de cada país. És per això que en el pas del temps s'ha vist necessària l'implicació de cada país en l'objectiu de gestionar de la millor manera possible el consum de dits recursos. Un dels problemes més importants és la necessitat de tractar l'aigua residual procedent dels núcleus urbans i industrials, en la finalitat de donar una calitat adequada a la mateixa en anterioritat a ser abocada al caixer públic. Els sistemes de control en les estacions de depuració d'aigües residuals (*EDAR) eixerciten un paper important ya que l'aigua residual afluent presenta una variabilitat sobre composició, cabal i càrrega contaminant, és per esta raó que en l'actualitat ha despertat un gran interés. En el present treball s'estudia el comportament d'una EDAR basada en l'esquema de tractament Bardenpho modificat. Ademés, s'utilisa el model BSM1 (De l'anglés: Benchmarck Simulation Model Nº1) per a estudiar l'efecte de la dinàmica de l'afluent sobre el procés i el model BNRM2 (De l'anglés: Biological Nutrient Removal Model Nº2) per a simular l'esquema de tractament. Per mig del software DESASS, s'ha implementat la EDAR estudi. S'ha implementat, calibrat i validat un sistema de control per mig del software LoDif BioControl, en l'objectiu d'optimisar el procés d'eliminació biològica de nitrogen, per mig d'un controlador de aireación basat en sonda d'amoni ABAC (De l'Inglés: Ammonia - Based Aeration Control)., [EN] The increase of the population at a global level consumes a consumption of available resources above the possibilities of each country, it is for that reason, that with the passage of time it has been necessary the implication by each country, of management in the best possible way. The most important problems is the need to treat wastewater from urban and industrial centers, in order to give adequate quality to the same before being poured into the public waterway. Control systems at sewage treatment plants (WWTPs) play an important role since the influent waste water has a variability in composition, flow rate and pollutant load, which is why it has now aroused a great deal of interest. This study the behavior of an EDAR based on the modified Bardenpho treatment scheme is studied. In addition, the models BSM1 (Benchmarck Simulation Model No. 1) is used to study the effect of the affluent dynamics on the process and the model BNRM2 (Biological Nutrient Removal Model No. 2) to simulate the treatment scheme. Through the DESASS software, the EDAR study has been implemented. A control system has been implemented, calibrated and validated by the software LoDif BioControl, with the objective of optimizing the process of biological nitrogen elimination, by means of an aeration controller based on ammonia probe ABAC (Ammonia - Based Aeration Control ).

[EN] Nowadays, the use of mathematical models and computer simulation allow analysis of many different technological solutions as well as testing various scenarios in a short time and at low financial budget in order to simulate the scenario under typical conditions for the real system and help to find the best solution in design or operation process. The aim of the study was to evaluate different concepts of biochemical processes and energy balance modeling using a simulation platform GPS-x and a comprehensive model Mantis2. The paper presents the example of calibration and validation processes in the biological reactor as well as scenarios showing an influence of operational parameters on the WWTP energy balance., [ES] En la actualidad, el uso de modelos matemáticos y la simulación por ordenador permiten el análisis de muchas soluciones tecnológicas diferentes, así como la prueba de diversos escenarios en poco tiempo y con un presupuesto financiero bajo para simular el escenario bajo condiciones típicas del sistema real y ayudar a encontrar la mejor solución en el proceso de diseño o operación. El objetivo del estudio fue evaluar diferentes conceptos de procesos bioquímicos y modelización del balance energético utilizando una plataforma de simulación GPS-x y un modelo integral Mantis2. El trabajo presenta el ejemplo de los procesos de calibración y validación en el reactor biológico, así como escenarios que muestran una influencia de los parámetros operacionales en el balance energético de la EDAR., [CA] En l'actualitat, l'ús de models matemàtics i la simulació per ordinador permeten l'anàlisi de moltes solucions tecnològiques diferents, així com la prova de diversos escenaris en poc temps i amb un pressupost financer baix per simular l'escenari sota condicions típiques del sistema real i ajudar a trobar la millor solució en el procés de disseny o operació. L'objectiu de l'estudi va ser avaluar diferents conceptes de processos bioquímics i modelització del balanç energètic utilitzant una plataforma de simulació GPS-x i un model integral Mantis2. El treball presenta l'exemple dels processos de calibratge i validació en el reactor biològic, així com escenaris que mostren una influència dels paràmetres operacionals en el balanç energètic de la EDAR.

[EN] The objective of this study was to assess the economic and environmental sustainability of submerged anaerobic membrane bioreactors (AnMBRs) in comparison with aerobic-based technologies for moderate-/high-loaded urban wastewater (UWW) treatment. To this aim, a combined approach of steady-state performance modelling, life cycle analysis (LCA) and life cycle costing (LCC) was used, in which AnMBR (coupled with an aerobic-based post-treatment) was compared to aerobic membrane bioreactor (AeMBR) and conventional activated sludge (CAS). AnMBR with CAS-based post-treatment for nutrient removal was identified as a sustainable option for moderate-/high-loaded UWW treatment: low energy consumption and reduced sludge production could be obtained at given operating conditions. In addition, significant reductions can be achieved in different aspects of environmental impact (global warming potential (GWP), abiotic depletion, acidification, etc.) and LCC over existing UWW treatment technologies.

[EN] The behavior of three different microalgal cultures, when exposed for a long period (>48 h) to dark conditions, was studied with a methodology based on respirometry. The cultures were transferred to darkness and the oxygen evolution in the reactors was monitored after successive air injections. Several sequential oxygen uptake rates were thus calculated and a respiration constant, assuming a first order decay of a fraction of the biomass, was obtained by calibration. Initial specific oxygen uptake rates were in the range of 0.9 5.1 mg O2 g TSS−1 h−1 and dark respiration constants in the range of 0.005 0.018 h−1.

Food waste was characterized for its potential use as substrate for anaerobic co-digestion in a submerged anaerobic membrane bioreactor pilot plant that treats urban wastewater (WW). 90% of the particles had sizes under 0.5 mm after grinding the food waste in a commercial food waste disposer. COD, nitrogen and phosphorus concentrations were 100, 2 and 20 times higher in food waste than their average concentrations in WW, but the relative flow contribution of both streams made COD the only pollutant that increased significantly when both substrates were mixed. As sulphate concentration in food waste was in the same range as WW, co-digestion of both substrates would increase the COD/SO4-S ratio and favour methanogenic activity in anaerobic treatments. The average methane potential of the food waste was 421 +/- 15 mL CH4 g(-1) VS, achieving 73% anaerobic biodegradability. The anaerobic co-digestion of food waste with WW is expected to increase methane production 2.9-fold. The settleable solids tests and the particle size distribution analyses confirmed that both treatment lines of a conventional WWTP (water and sludge lines) would be clearly impacted,by the incorporation of food waste into its influent. Anaerobic processes are therefore preferred over their aerobic counterparts due to their ability to valorise the high COD content to produce biogas (a renewable energy) instead of increasing the energetic costs associated with the aeration process for aerobic COD oxidation. (C) 2016 Elsevier Ltd. All rights reserved.

[EN] It has been found that in industrial wastewater treatment plants, or those with a previous process of coagulation-flocculation, sludge does not settle conventionally since there is not a unique hindered settling stage. Chen et al. (1996) and Zhao (2004a, 2004b) observed during the settling tests, an initial stage with constant hindered settling velocity, an intermediate stage of accelerating settling velocity and a final stage with constant settling velocity once again. This form of activated sludge settleability has not been studied in detail. Chen et al. (1996) and Zhao (2004a, 2004b) studied the stages with constant zone settling velocity, but they did not study or model the accelerating process of the sludge, nor paid attention to the moment at which this process starts taking place. They did not explain the mechanism that triggers the process of acceleration of settling rate, or the formation of large flocs with an initial homogeneous structure. The secondary clarifiers in biological wastewater treatment plants are mostly designed from empirical criteria based on acquired experience in the design of urban treatment plants. The use of these criteria can be a problem in industrial plants where the biological sludge settleability may be affected by the type of wastewater and the physico-chemical treatment. The same happens when simulation programs are used to estimate hindered settling velocity of activated sludge from empirical formula developed at urban treatment plants. Modelling hindered settling velocity for activated sludge in such treatment plants can help to improve the methods used for the design and simulation of secondary clarifiers. The main objective of this thesis is the study and development of a general model for the hindered settling velocity and the accelerating process for the activated sludge in wastewater treatment plants. The activated sludge used for settling tests come from the industrial wastewater treatment plant of Ford Spain. Initi, [ES] Se ha comprobado que con cierta frecuencia en depuradoras de aguas residuales industriales o en depuradoras con un proceso de coagulación-floculación previo, los fangos no sedimentan de modo convencional debido a que no presentan una única etapa de sedimentación zonal. Chen et al. (1996) y Zhao (2004a, 2004b) observaron en ensayos de sedimentación con este tipo de fangos, una etapa inicial con velocidad de sedimentación zonal constante, una etapa intermedia donde se producía la aceleración de los fangos y una etapa final donde la velocidad de sedimentación zonal volvía a ser constante. Este modo de sedimentación de los fangos activados no se ha estudiado con detalle. Chen et al. (1996) y Zhao (2004a, 2004b) estudiaron las etapas con velocidad de sedimentación zonal constante, pero no estudiaron ni modelizaron el proceso de aceleración del fango, ni le prestaron atención al tiempo a partir del cual se produce este proceso. Tampoco explicaron el mecanismo que desencadena el proceso de aceleración, ni la formación de grandes flóculos partiendo de un fango con una estructura inicial homogénea. Los decantadores secundarios en los tratamientos biológicos de aguas residuales son mayoritariamente diseñados a partir de criterios empíricos basados en la experiencia adquirida en el diseño de depuradoras urbanas. El uso de estos criterios puede ser problemático en depuradoras de aguas residuales industriales donde la sedimentabilidad del fango biológico puede verse afectada por el tipo de agua residual y por el tratamiento físico-químico previo. Lo mismo ocurre cuando se utilizan programas de simulación donde se calcula la velocidad de sedimentación zonal de los fangos activados a partir de fórmulas empíricas obtenidas en depuradoras urbanas. La modelización de la velocidad de sedimentación zonal de los fangos activados en este tipo de depuradoras puede ayudar a mejorar los métodos utilizados para el diseño y simulación de decantadores secundarios. El objetivo principal de, [CA] S'ha comprovat que amb certa freqüència en depuradores d'aigües residuals industrials o en depuradores amb un procés de coagulació-floculació previ, els fangs no sedimenten de manera convencional pel fet de no presentar una única etapa de sedimentació zonal. Chen et al. (1996) i Zhao (2004a, 2004b) van observar en assajos de sedimentació amb aquest tipus de fangs, una etapa inicial amb velocitat de sedimentació zonal constant, una etapa intermèdia on es produïa l'acceleració dels fangs i una etapa final on la velocitat de sedimentació zonal tornava a ser constant. Esta manera de sedimentació dels fangs activats no s'ha estudiat amb detall. Chen et al. (1996) i Zhao (2004a, 2004b) van estudiar les etapes amb velocitat de sedimentació zonal constant, però no van estudiar ni modelitzar el procés d'acceleració del fang, ni li van prestar atenció al temps a partir del qual es produeix este procés. Tampoc van explicar el mecanisme que desencadena el procés d'acceleració, ni la formació de grans flòculs partint d'un fang amb una estructura inicial homogènia. Els decantadors secundaris en els tractaments biològics d'aigües residuals són majoritàriament dissenyats a partir de criteris empírics basats en l'experiència adquirida en el disseny de depuradores urbanes. L'ús d'estos criteris pot ser problemàtic en depuradores d'aigües residuals industrials on la sedimentabilidad del fang biològic es pot veure's afectada pel tipus d'aigua residual i pel tractament fisicoquímic previ. El mateix passa quan s'utilitzen programes de simulació on es calcula la velocitat de sedimentació zonal dels fangs activats a partir de fórmules empíriques obtingudes en depuradores urbanes. La modelització de la velocitat de sedimentació zonal dels fangs activats en este tipus de depuradores pot ajudar a millorar els mètodes utilitzats per al disseny i simulació de decantadors secundaris. L'objectiu principal de la present tesi és estudiar i desenvolupar un model general de la velocitat de sedim

Tesis por compendio, [EN] Anaerobic membrane bioreactors for urban wastewater treatment present interesting advantages when compared with aerobic treatments, such as less sludge production, lower energy demand and biogas generation. However, the generated effluent cannot generally be discharged without further ammonium and phosphate elimination. This thesis studies the removal of these inorganic nutrients by means of microalgae cultivation. The main objective of this work is therefore to obtain an autochthonous microalgal culture and to investigate its ability to grow on an already existing anaerobic effluent, as well as to research the extent to which ammonium and phosphate can be removed. Moreover, this thesis aims at providing the kinetic expressions which reproduce the main processes involved, in order to provide the basis for process simulation and design. Microalgae were isolated from a local wastewater treatment plant and their ability to grow on the anaerobic effluent -while successfully removing ammonium and phosphate- was demonstrated. An excellent water quality was obtained with a semicontinuous cultivation mode under constant illumination. The Scenedesmus and Chlorococcum genus proliferated more efficiently and thus became predominant in the culture. Results also showed that phosphorus was the limiting nutrient in the anaerobic effluent to be treated. The influence of phosphorus limitation on ammonium and phosphate removal, as well as the influence of temperature in ammonium removal, were then studied under laboratory conditions. Kinetic expressions which reproduce the observed effects were proposed and validated, taking also into account the effect of light intensity. Additionally, a Scenedesmus-dominated culture was grown under varying light and temperature in an outdoor flat-plate photobioreactor, with constant monitoring of light intensity, temperature and ammonium concentration. Acceptable results were obtained in the reproduction of the experimental data, albeit with l, [ES] En el tratamiento de aguas residuales urbanas, los bioreactores anaerobios de membranas presentan ventajas interesantes frente a los tratamientos aerobios. Algunas de estas ventajas son la menor producción de fangos, un menor consumo energético y la producción de biogás. Sin embargo, y generalmente, el efluente obtenido no puede ser vertido al medio sin una etapa previa de eliminación de amonio y fosfato. La presente tesis estudia la eliminación de dichos nutrientes inorgánicos empleando para ello un cultivo de microalgas. El objetivo principal de este trabajo es, por tanto, la obtención de un cultivo autóctono de microalgas y la evaluación de la capacidad que éstas tienen tanto de crecer en un efluente anaerobio como de eliminar el amonio y el fosfato presentes. Asimismo, se pretenden proporcionar las bases para la simulación y el diseño del sistema de depuración propuesto, mediante la obtención de las expresiones cinéticas que reproducen los principales procesos involucrados. En primer lugar se ha demostrado la capacidad de las microalgas, aisladas en una estación depuradora de aguas residuales, de crecer en el efluente anaerobio y de eliminar con éxito el amonio y fosfato en éste presente. El agua tratada, obtenida a mediante un proceso semicontinuo y con iluminación constante, presenta una excelente calidad. Los géneros Scenedesmus y Chlorococcum han proliferado más eficientemente y han llegado a ser los predominantes en el cultivo. Los resultados obtenidos indican que el nutriente limitante en el efluente a tratar es el fósforo, y por tanto la influencia de la limitación de fósforo en la eliminación de nutrientes ha sido estudiada en condiciones de laboratorio, junto con la influencia de la temperatura en la velocidad de eliminación de amonio. Han sido propuestas y validadas las correspondientes expresiones cinéticas que reproducen los efectos observados, teniendo en cuenta en todo momento la influencia de la intensidad de la luz. Por otro lado, un cultivo, [CA] En el tractament d'aigües residuals urbanes, els bioreactors anaerobis de membrana tenen avantatges interessants respecte als tractaments aerobis. Alguns d'aquests avantatges són: menys producció de fangs, menys consum energètic i la producció de biogàs. No obstant això, i en general, l'efluent obtingut no es pot tornar al medi sense una etapa prèvia d'eliminació d'amoni i fosfat. Aquesta tesi estudia l'eliminació d'aquests nutrients inorgànics emprant per a fer-ho un cultiu de microalgues. L'objectiu principal d'aquest treball és, per tant, l'obtenció d'un cultiu autòcton de microalgues i l'avaluació de la capacitat que aquestes tenen tant de créixer en un efluent anaerobi com d'eliminar l'amoni i el fosfat presents. Així mateix, volem proporcionar les bases per a la simulació i el disseny del sistema de depuració proposat, mitjançant l'obtenció de les expressions cinètiques que reprodueixen els principals processos involucrats. En primer lloc, s'ha demostrat la capacitat de les microalgues, aïllades en una estació depuradora d'aigües residuals, de créixer en l'efluent anaerobi i d'eliminar amb èxit l'amoni i el fosfat presents. L'aigua tractada, obtinguda mitjançant un procés semicontinu i amb il·luminació constant, presenta una qualitat excel·lent. Els gèneres Scenedesmus i Chlorococcum han proliferat més eficientment i han arribat a ser els predominants en el cultiu. Els resultats obtinguts indiquen que el nutrient limitant en l'efluent per tractar és el fòsfor, i per tant la influència de la limitació de fòsfor en l'eliminació tant d'amoni com de fosfat ha sigut estudiada en condicions de laboratori, juntament amb la influència de la temperatura en la velocitat d'eliminació d'amoni. S'han proposat i validat les expressions cinètiques corresponents que reprodueixen els efectes observats, tenint en compte en tot moment la influència de la intensitat de la llum. D'altra banda, s'ha cultivat a l'exterior un cultiu predominat per Scenedesmus, sota condicions ca

[EN] The objective of this study was to evaluate the economic and environmental sustainability of a sub- merged anaerobic membrane bioreactor (AnMBR) treating urban wastewater (UWW) and organic fraction of municipal solid waste (OFMSW) at ambient temperature in mild/hot climates. To this aim, power requirements, energy recovery from methane (biogas methane and methane dissolved in the effluent), consumption of reagents for membrane cleaning, and sludge handling (polyelectrolyte and energy consumption) and disposal (farmland, landfilling and incineration) were evaluated within different operating scenarios. Results showed that, for the operating conditions considered in this study, AnMBR technology is likely to be a net energy producer, resulting in considerable cost savings (up to V0.023 per m3 of treated water) when treating low-sulphate influent. Life cycle analysis (LCA) results revealed that operating at high sludge retention times (70 days) and treating enhances the overall environmental performance of AnMBR technology.

[EN] The objective of this study was to evaluate the effect of the main factors affecting the cost of the filtration process in submerged anaerobic membrane bioreactors (AnMBRs) for urban wastewater (UWW) treatment. Experimental data for CAPEX/OPEX calculations was obtained in an AnMBR system featuring industrial-scale hollow-fiber (HF) membranes. Results showed that operating at J(20) slightly higher than the critical flux results in minimum CAPEX/OPEX. The minimum filtration process cost ranged from Euro0.03 to Euro0.12 per m(3), mainly depending on SGD(m) (from 0.05 to 0.3 m(3)m(-2)h(-1)) and MLSS (from 5 to 25 gL-1). The optimal SGD(m) resulted in approx. 0.1 m(3)m(-2)h(-1).

The effect of temperature on microalgal ammonium uptake was investigated by carrying out four batch experiments in which a mixed culture of microalgae, composed mainly of Scenedesmus sp., was cultivated under different temperatures within the usual temperature working range in Mediterranean climate (15-34 ºC). Ammonium removal rates increased with temperature up to 26 ºC and stabilized thereafter. Ratkowsky and Cardinal Temperatures models successfully reproduced the experimental data. Optimum (31.3 ºC), minimum (8.8 ºC) and maximum (46.1 ºC) temperatures for ammonium removal by Scenedesmus sp. under the studied conditions were obtained as model parameters. These temperature-related parameters constitute very useful information for designing and operating wastewater treatment systems using these microalgae.

[EN] The main objective of this study is to propose guidelines for designing submerged anaerobic MBR (AnMBR) technology for municipal wastewater treatment. The design methodology was devised on the basis of simulation and experimental results from an AnMBR plant featuring industrial-scale hollow-fibre membranes. The proposed methodology aims to minimise both capital expenditure and operating expenses, and the key parameters considered were: hydraulic retention time, solids retention time, mixed liquor suspended solids concentration in the membrane tank, 20 C-standardised critical flux, specificgas demand per square metre of membrane area, and flow of sludge being recycled from the membrane tank to the anaerobic reactor. An AnMBR WWTP operating at 15 and 30 C with both sulphate-rich (5.7 mg COD mg 1 SO4-S) and low-sulphate (57 mg COD mg 1 SO4-S) municipal wastewater was designed. The minimum cost of the designed plant was 0.097 and 0.070 per m3 when treating sulphate- rich and low-sulphate wastewater, respectively.

The present work determines the effect of phosphorus content on phosphate uptake rate in a mixed culture of Chlorophyceae in which the genus Scenedesmus dominates. Phosphate uptake rate was determined in eighteen laboratory batch experiments, with samples taken from a progressively more P-starved culture in which a minimum P content of 0.11% (w/w) was achieved. The results obtained showed that the higher the internal biomass P content, the lower the phosphate removal rate. The highest specific phosphate removal rate was 6.5 mgPO4 P gTSS -1 h -1 . Microalgae with a P content around 1% (w/w) attained 10% of this highest removal rate, whereas those with a P content of 0.6% (w/w) presented 50% of the maximum removal rate. Different kinetic expressions were used to reproduce the experimental data. Best simulation results for the phosphate uptake process were obtained combining Steele equation and Hill function to represent the effect of light and intracellular phosphorus content, respectively.

A submerged anaerobic membrane bioreactor (AnMBR) demonstration plant with two commercial hollow-fibre ultrafiltration systems (PURON® , Koch Membrane Systems, PUR-PSH31) was designed and operated for urban wastewater treatment. An instrumentation, control, and automation (ICA) system was designed and implemented for proper process performance. Several single-input-single-output (SISO) feedback control loops based on conventional on off and PID algorithms were implemented to control the following operating variables: flow-rates (influent, permeate, sludge recycling and wasting, and recycled biogas through both reactor and membrane tanks), sludge wasting volume, temperature, transmembrane pressure, and gas sparging. The proposed ICA for AnMBRs for urban wastewater treatment enables the optimization of this new technology to be achieved with a high level of process robustness towards disturbances.

This work studies the use of a well-known and spread activated sludge system (UCT configuration) to treat the effluent of a submerged anaerobic membrane bioreactor (SAnMBR) treating domestic waste-water. Ammonia, phosphate, dissolved methane and sulphide concentrations in the SAnMBR effluent were around 55 mg NH4-N L-1, 7 mg PO4-P L-1, 30 mg non-methane biodegradable COD L-1, and 105 mg S2- L-1 respectively. The results showed a nitrification inhibition caused by the presence of sulphur compounds at any of the solids retention time (SRT) studied (15,20 and 25 days). This inhibition could be overcome increasing the hydraulic retention time (HRT) from 13 to 26 h. Among the sulphur compounds, sulphide was identified as the substance which caused the nitrification inhibition. When the nitrification was well established, removal rates of nitrogen and phosphorus of 56% and 45% were reached respectively. The sulphide present in the influent was completely oxidised to sulphate, contributing this oxidation to the denitrification process. Moreover, the presence of methanotrophic bacteria, detected by FISH technique, could also contribute to the denitrification. (C) 2014 Elsevier Ltd. All rights reserved.

[ES] Los efluentes procedentes de las aguas residuales contienen concentraciones elevadas de nutrientes (NH4+, NO2-, NO3- and PO43-) que son los responsables de ocasionar la eutrofización en las aguas naturales. Por lo tanto, según la legislación vigente, las aguas residuales deben de ser tratadas adecuadamente antes de ser vertidas a los cauces naturales. Las microalgas pueden desempeñar un papel efectivo en el tratamiento terciario de las aguas residuales urbanas, como se ha confirmado en muchos estudios (Abdel-Raouf et al 2012; Arzib et al. 2013; Ruiz-Marin et al.2010). En este trabajo se han utilizado tres cepas de microalgas (Chlamydomonas reinhardtii, Chlorella vulgaris y Scendesmus obliquus) en cultivos puros y cultivos mixtos. Se ha tratado de comparar sus rendimientos poniendo a prueba su capacidad de eliminar el nitrógeno-amoniacal (N-NH4+) y el ortofosfato (P-PO43-) para un efluente procedente de un reactor anaerobio de membranas (SAnMBR). Las microalgas con el mejor crecimiento celular fueron seleccionadas, y se presentan como un tratamiento adecuado para la eliminación de nutrientes. Los resultados indican que Chlorella vulgaris (SAG 211-12) obtiene velocidades de eliminación de fosforo superiores (100%) y Chlamydomonas reinhardtii (SAG 11-32b) a su temperatura óptima de crecimiento, muestra una mayor tasa de eliminación de nitrógeno (100%) y de fosfatos (100%) en comparación con las otras especies. Estudiando la competencia ecológica entre las especies en el cultivos mixtos, los resultados indican que Chlorella vulgaris fue el organismo más resistente., [CA] Els efluents procedents de les aigües residuals contenen concentracions elevades de nutrients (NH4 +, NO2-, NO3- and PO43-) que són els responsables d'ocasionar l'eutrofització en les aigües naturals. Per tant, segons la legislació vigent, les aigües residuals les han de tractar adequadament abans de ser abocades a les lleres naturals. Les microalgues poden tenir un paper important en el tractament terciari de les aigües residuals urbanes, com s'ha confirmat en molts estudis (Abdel-Raouf et al 2012; Arzib et al. 2013; Ruiz-Marin et al.2010). En aquest treball s'han utilitzat tres tipus de microalgues (Chlamydomonas reinhardtii, Chlorella vulgaris i Scendesmus obliquus) en cultius purs i cultius mixtes. S'ha tractat de comparar els seus rendiments posant a prova la seva capacitat d'eliminar el nitrogen-amoniacal (N-NH4+) i el ortofosfato (P-PO43-) per a un efluent procedent d'un reactor anaerobi de membranes (SAnMBR). Les microalgues amb el millor creixement cel·lular van ser seleccionades, i es presenten com un tractament adequat per a l'eliminació de nutrients. Els resultats indiquen que Chlorella vulgaris (SAG 211-12) obté velocitats d'eliminació de fòsfor superiors (100%) i Chlamydomonas reinhardtii (SAG 11-32b), a la seua temperatura óptima de creixement, mostra una major taxa d'eliminació de nitrogen (100%) i de fósfor (100%) en comparació amb les altres espècies. Estudiant la competència ecològica entre les espècies en el cultiu mixte, els resultats indiquen que Chlorella vulgaris va ser l'organisme més resistent., [EN] The effluents from wastewater contain nutrients (NH4+, NO2-, NO3- and PO43-) which have been identified as the main causes leading to eutrophication in natural waters. Therefore, according to the legislation, the wastewater must receive suitable treatment before being discharged into water bodies. Microalgae play an effective role during urban waste water treatment, many studies support it (Abdel-Raouf et al 2012; Arzib et al. 2013; Ruiz-Marin et al.2010). In this work three strains of microalgae (Chlamydomonas reinhardtii, Chlorella vulgaris y Scendesmus obliquus) growing as pure cultures and mixed cultures were used and compared to test their ability to remove nitrogen-ammonia (NH4+-N) and orthophosphate(PO43- -P) in batch cultures, using an anaerobic membrane bioreactor effluent. The microalgae with the best cell growth rate were selected, and introduced as a suitable train for nutrient removal. Results indicate that Chlorella vulagaris (SAG 211-12) showed a higher P uptake rate (100%) and Chlamydomonas reinhardtii (SAG 11-32b) at her optimum of temperature showed a higher N up take rate (100%) and higher P up take rate (100%) in urban wastewater than the other species. Also about the ecological competition between the species, the results indicate that Chlorella vulgaris was the organism most resistant.

Eight different phenotypes were studied in an activated sludge process (AeR) and anaerobic digester AnD) in a full-scale wastewater treatment plant by means of fluorescent in situ hybridization (FISH) and automated FISH quantification software. The phenotypes were ammonia-oxidizing bacteria, nitrite-oxidizing bacteria, denitrifying bacteria, phosphate-accumulating organisms (PAO), glycogen-accumulating organisms (GAO), sulphate-reducing bacteria (SRB), methanotrophic bacteria and methanogenic archaea. Some findings were unexpected: (a) Presence of PAO, GAO and denitrifiers in the AeR possibly due to unexpected environmental conditions caused by oxygen deficiencies or its ability to survive aerobically; (b) presence of SRB in the AeR due to high sulphate content of wastewater intake and possibly also due to digested sludge being recycled back into the primary clarifier; (c) presence of methanogenic archaea in the AeR, which can be explained by the recirculation of digested sludge and its ability to survive periods of high oxygen levels; (d) presence of denitrifying bacteria in the AnD which cannot be fully explained because the nitrate level in the AnD was not measured. However, other authors reported the existence of denitrifiers in environments where nitrate or oxygen was not present suggesting that denitrifiers can survive in nitrate-free anaerobic environments by carrying out low-level fermentation; (e) the results of this paper are relevant because of the focus on the identification of nearly all the significant bacterial and archaeal groups of microorganisms with a known phenotype involved in the biological wastewater treatment.

[ES] El ritmo de crecimiento de la población en las últimas décadas, el desarrollo tecnológico y los cambios en el modo de vida de la sociedad están afectando negativamente a la calidad y la disponibilidad de los recursos naturales disponibles, entre ellos el agua. El modelo de gestión hídrica actual está obsoleto, por lo que es necesario un cambio generalizado en el que se tenga en cuenta la necesidad de tratamiento y recuperación las aguas contaminadas tras su utilización. A su vez, las técnicas a aplicar deben estar basadas en la sostenibilidad tanto económica como medioambiental, siendo una de estas opciones alternativas la utilización de cultivos de microalgas. Las microalgas tienen la capacidad de eliminar tanto la materia orgánica como los nutrientes presentes en el agua. La utilización de este tipo de cultivo para el tratamiento de aguas residuales supone una reducción de las necesidades energéticas, y por tanto da como resultado un proceso más económicamente rentable que los convencionales fangos activos. Del mismo modo, la biomasa generada tiene aplicación industrial en otros ámbitos por lo que pasa a considerarse subproducto en lugar de residuo. El objetivo principal de este trabajo ha sido la determinación experimental de la influencia de las características del alimento, el tipo de aireación, la variación de temperatura y la intensidad lumínica en la eliminación de nutrientes de un efluente de un reactor anaerobio de membranas mediante un cultivo de microalgas en planta piloto. Durante el período de experimentación se han determinado los rendimientos de eliminación de nutrientes (amonio y fosfato), se ha estudiado el crecimiento del cultivo y se ha observado la evolución poblacional de las especies de microalgas presentes, todo ello con la finalidad de relacionar los resultados con las condiciones de operación presentes en cada ensayo. Tras el período de experimentación los resultados mostraron que el uso de un alimento artificial permitía un desarrollo, [CA] El ritme de creixement de la població en les últimes dècades, el desenvolupament tecnològic i els canvis en el mode de vida de la societat estan afectant negativament a la qualitat i la disponibilitat dels recursos naturals disponibles, entre ells l’aigua. El model de gestió hídrica actual està obsolet, pel que és necessari un canvi generalitzat en el que es tingui en compte la necessitat de tractament i recuperació de les aigües contaminades després del seu ús. Al mateix temps, les tècniques a aplicar deuen d’estar basades en la sostenibilitat tant econòmica com ambiental, sent una d’aquestes opcions alternatives el ús de cultius de microalgues. Les microalgues tenen la capacitat d’eliminar tant la matèria orgànica com els nutrients presents en l’aigua. La utilització d’aquest tipus de cultiu per al tractament d’aigües residuals suposa una reducció de les necessitats energètiques, i per tant esdevé un procés més econòmicament rentable que fangs actius convencionals. A més, la biomassa generada té aplicació industrial pel que passa a considerar-se subproducte en lloc de residu. L’objectiu principal d’aquest treball ha estat la determinació experimental de la influencia de les característiques de l’aliment, el tipus de ventilació, la variació de temperatura i la intensitat lumínica en la eliminació de nutrients d’un efluent procedent d’un reactor anaerobi de membranes mitjançant un cultiu de microalgues en una planta pilot. Durant el període d’experimentació s’han determinat els rendiments d’eliminació de nutrients (amoni i fosfat), s’ha estudiat el creixement del cultiu i s’ha observat la evolució poblacional de les especies de microalgues presents, tot amb la finalitat de relacionar els resultats amb les condiciones d’operació presents en cada assaig. Acabada la experimentació, els resultats van mostrar que el ús d’un aliment artificial permetia un desenvolupament del cultiu similar al observat en condicions normals. La reducció de la mida de bombolla va promo, [EN] The population growth rate during last decades, technological development and changes in the lifestyle of society are negatively affecting the quality and availability of natural resources, including water. Current management model of water is obsolete, so it is necessary a global change. The new model must take into account the treatment and recovery requirements for polluted water after its use. Moreover, applied technologies should be based on sustainability values. One of these new methods is the use of microalgae cultures. Microalgae are able to remove organic matter and nutrients contained in water. The use of this kind of culture for wastewater treatment decreases energy needs. Therefore, microalgae cultures involve more cost-effective technology than conventional activated sludge process. In addition, generated biomass can be used in industry so then it can be regarded as by-product rather than waste. The aim of this work was the experimental determination of the influence of food features, type of ventilation, temperature variability and light intensity in nutrient removal in effluent from AnMBR pilot plant. During experimental period, nutrient removal yields (ammonia and phosphate) were determined, growth rate was studied and microalgae species evolution was observed. The main target of these procedures was to relate the results with operational conditions in each test. After experimental period, results showed that the use of an artificial feed allowed a similar development compared with harvests under normal conditions. The bubble size reduction promoted the proliferation of cyanobacteria. The influence of temperature variation was not significant, and it can be explained with the hypothetical statement that photobioreactors were operating under optimal temperature range. Light intensity reduction reported negative effects on microalgae growth, consequently photosynthetic activity reduced and elimination yield lowed.

The objective of this study was to evaluate the operating cost of an anaerobic membrane bioreactor (AnMBR) treating sulphate-rich urban wastewater (UWW) at ambient temperature (ranging from 17 to 33 degrees C). To this aim, energy consumption, methane production, and sludge handling and recycling to land were evaluated. The results revealed that optimising specific gas demand with respect to permeate volume (SGDp) and sludge retention time (for given ambient temperature conditions) is essential to maximise energy savings (minimum energy demand: 0.07 kW h m(-3)). Moreover, low/moderate sludge productions were obtained (minimum value: 0.16 kg TSS kg(-1) CODRemoved), which further enhanced the overall operating cost of the plant (minimum value: is an element of 0.011 per m(3) of treated water). The sulphate content in the influent UWW significantly affected the final production of methane and thereby the overall operating cost. Indeed, the evaluated AnMBR system presented energy surplus potential when treating low-sulphate UWW