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

New insights in the metabolic behaviour of PAO under negligible poly-P reserves

[EN] In a previous study the authors confirmed the ability of PAOs to perform GAO metabolism in short-term experiments. However, what happens when PAOs are exposed to poly-P shortage for an extended period of time? The answer to this question was the aim of this work from a macroscopic and microscopic point of view. Therefore, the poly-P was removed from a PAO enriched SBR and maintained without poly-P during five solid retention time. The PAOs were found to quickly change their metabolism to a clear GAO performance and remained without GAO colonization for the entire experimental period, even though GAO was present (around 5%) at the beginning of the experiment. Unlike the results obtained in the short-term experiments, in this case PAO Type I performed the GAO metabolism at the end of the experimental period. (C) 2016 Elsevier B.V. All rights reserved.This research work has been supported by the Generalitat Valenciana (GVPRE/2008/044) and the Polytechnic University of Valencia (PAID-06-08-3227), which are gratefully acknowledged. Special acknowledgements to the Consejo Nacional de Ciencia y Tecnologia de Mexico (CONACYT) No. 207966.Acevedo Juárez, B.; Murgui Mezquita, M.; Borrás Falomir, L.; Barat, R. (2017). New insights in the metabolic behaviour of PAO under negligible poly-P reserves. Chemical Engineering Journal. 311:82-90. https://doi.org/10.1016/j.cej.2016.11.073S829031

An integral approach to sludge handling in a WWTP operated for EBPR aiming phosphorus recovery: simulation of alternatives, LCA and LCC analyses

©IWA Publishing 2020. The definitive peer-reviewed and edited version of this article is published in Water Research, Volume 175, 15 May 2020, 115647, https://doi.org/10.1016/j.watres.2020.115647 and is available at www.iwapublishing.com.[EN] As phosphorus is a non-renewable resource mainly used to produce fertilizers and helps to provide food all over the world, the proper management of its reserves is a global concern since it is expected to become scarcer in the near future. In this work we assessed two different sludge line configurations aiming for P extraction and recovery before anaerobic digestion and compared them with the classical configuration. This study has been performed by simulation with the model BNRM2 integrated in the software package DESASS 7.1. Configuration 1 was based on the production of a PO4-enriched stream from sludge via elutriation in the primary thickeners, while Configuration 2 was based on the WASSTRIP (R) process and its PO4-enriched stream was mechanically obtained with dynamic thickeners. In both alternatives recovery was enhanced by promoting poly-phosphate (poly-P) extraction under anaerobic conditions, for which both configurations were fully evaluated in a full-scale WWTP. Both were also optimized to maximize phosphorus extraction. Their costs and life cycles were also analysed. The novelty of this research lies in the lack of literature about the integral evaluation of pre-anaerobic digestion P recovery from wastewaters. This study included a holistic approach and an optimization study of both alternatives plus their economic and environmental aspects. In Configuration 1, the PO4-P load in the recovery stream reached 43.1% of the total influent P load and reduced uncontrolled P-precipitation in the sludge line up to 52.9%. In Configuration 2, extraction was 48.2% of the influent P load and it reduced precipitation by up to 60.0%. Despite Configuration 1's lower phosphorus recovery efficiency, it had a 23.0% lower life cycle cost and a 14.2% lower global warming impact per hm(3) of treated influent than Configuration 2. Configuration 1 also reduced the TAEC by 17.6% and global warming impact by 2.0% less than Configuration 0.The LIFE Programme, the European Union's funding instrument for the environment and climate action, supported and co-funded this study as part of the LIFE ENRICH project (LIFE16 ENV/ES/000375).Roldán, M.; Bouzas, A.; Seco, A.; Mena, E.; Mayor, Á.; Barat, R. (2020). An integral approach to sludge handling in a WWTP operated for EBPR aiming phosphorus recovery: simulation of alternatives, LCA and LCC analyses. Water Research. 175:1-11. https://doi.org/10.1016/j.watres.2020.115647S111175Bouzas, A., Martí, N., Grau, S., Barat, R., Mangin, D., & Pastor, L. (2019). Implementation of a global P-recovery system in urban wastewater treatment plants. Journal of Cleaner Production, 227, 130-140. doi:10.1016/j.jclepro.2019.04.126Bradford-Hartke, Z., Lane, J., Lant, P., & Leslie, G. (2015). Environmental Benefits and Burdens of Phosphorus Recovery from Municipal Wastewater. Environmental Science & Technology, 49(14), 8611-8622. doi:10.1021/es505102vCieślik, B., & Konieczka, P. (2017). A review of phosphorus recovery methods at various steps of wastewater treatment and sewage sludge management. The concept of «no solid waste generation» and analytical methods. Journal of Cleaner Production, 142, 1728-1740. doi:10.1016/j.jclepro.2016.11.116Cornel, P., & Schaum, C. (2009). Phosphorus recovery from wastewater: needs, technologies and costs. Water Science and Technology, 59(6), 1069-1076. doi:10.2166/wst.2009.045Cullen, N., Baur, R., & Schauer, P. (2013). Three years of operation of North America’s first nutrient recovery facility. Water Science and Technology, 68(4), 763-768. doi:10.2166/wst.2013.260Egle, L., Rechberger, H., Krampe, J., & Zessner, M. (2016). Phosphorus recovery from municipal wastewater: An integrated comparative technological, environmental and economic assessment of P recovery technologies. Science of The Total Environment, 571, 522-542. doi:10.1016/j.scitotenv.2016.07.019Ferrer, J., Pretel, R., Durán, F., Giménez, J. B., Robles, A., Ruano, M. V., … Seco, A. (2015). Design methodology for submerged anaerobic membrane bioreactors (AnMBR): A case study. Separation and Purification Technology, 141, 378-386. doi:10.1016/j.seppur.2014.12.018Ferrer, J., Seco, A., Serralta, J., Ribes, J., Manga, J., Asensi, E., … Llavador, F. (2008). DESASS: A software tool for designing, simulating and optimising WWTPs. Environmental Modelling & Software, 23(1), 19-26. doi:10.1016/j.envsoft.2007.04.005Guedes, P., Couto, N., Ottosen, L. M., & Ribeiro, A. B. (2014). Phosphorus recovery from sewage sludge ash through an electrodialytic process. Waste Management, 34(5), 886-892. doi:10.1016/j.wasman.2014.02.021Guérin-Schneider, L., Tsanga-Tabi, M., Roux, P., Catel, L., & Biard, Y. (2018). How to better include environmental assessment in public decision-making: Lessons from the use of an LCA-calculator for wastewater systems. Journal of Cleaner Production, 187, 1057-1068. doi:10.1016/j.jclepro.2018.03.168Harrison, E. Z., Oakes, S. R., Hysell, M., & Hay, A. (2006). Organic chemicals in sewage sludges. Science of The Total Environment, 367(2-3), 481-497. doi:10.1016/j.scitotenv.2006.04.002Le Corre, K. S., Valsami-Jones, E., Hobbs, P., & Parsons, S. A. (2009). Phosphorus Recovery from Wastewater by Struvite Crystallization: A Review. Critical Reviews in Environmental Science and Technology, 39(6), 433-477. doi:10.1080/10643380701640573Lizarralde, I., Fernández-Arévalo, T., Manas, A., Ayesa, E., & Grau, P. (2019). Model-based opti mization of phosphorus management strategies in Sur WWTP, Madrid. Water Research, 153, 39-52. doi:10.1016/j.watres.2018.12.056Marti, N., Bouzas, A., Seco, A., & Ferrer, J. (2008). Struvite precipitation assessment in anaerobic digestion processes. Chemical Engineering Journal, 141(1-3), 67-74. doi:10.1016/j.cej.2007.10.023Nättorp, A., Remmen, K., & Remy, C. (2017). Cost assessment of different routes for phosphorus recovery from wastewater using data from pilot and production plants. Water Science and Technology, 76(2), 413-424. doi:10.2166/wst.2017.212Neethling, J. B., & Benisch, M. (2004). Struvite control through process and facility design as well as operation strategy. Water Science and Technology, 49(2), 191-199. doi:10.2166/wst.2004.0122Pastor, L., Marti, N., Bouzas, A., & Seco, A. (2008). Sewage sludge management for phosphorus recovery as struvite in EBPR wastewater treatment plants. Bioresource Technology, 99(11), 4817-4824. doi:10.1016/j.biortech.2007.09.054Peng, L., Dai, H., Wu, Y., Peng, Y., & Lu, X. (2018). A comprehensive review of phosphorus recovery from wastewater by crystallization processes. Chemosphere, 197, 768-781. doi:10.1016/j.chemosphere.2018.01.098Robles, Á., Aguado, D., Barat, R., Borrás, L., Bouzas, A., Giménez, J. B., … Seco, A. (2020). New frontiers from removal to recycling of nitrogen and phosphorus from wastewater in the Circular Economy. Bioresource Technology, 300, 122673. doi:10.1016/j.biortech.2019.122673Rodriguez-Garcia, G., Frison, N., Vázquez-Padín, J. R., Hospido, A., Garrido, J. M., Fatone, F., … Feijoo, G. (2014). Life cycle assessment of nutrient removal technologies for the treatment of anaerobic digestion supernatant and its integration in a wastewater treatment plant. Science of The Total Environment, 490, 871-879. doi:10.1016/j.scitotenv.2014.05.077Sena, M., & Hicks, A. (2018). Life cycle assessment review of struvite precipitation in wastewater treatment. Resources, Conservation and Recycling, 139, 194-204. doi:10.1016/j.resconrec.2018.08.009Shih, Y.-J., Abarca, R. R. M., de Luna, M. D. G., Huang, Y.-H., & Lu, M.-C. (2017). Recovery of phosphorus from synthetic wastewaters by struvite crystallization in a fluidized-bed reactor: Effects of pH, phosphate concentration and coexisting ions. Chemosphere, 173, 466-473. doi:10.1016/j.chemosphere.2017.01.088Van Dijk, K. C., Lesschen, J. P., & Oenema, O. (2016). Phosphorus flows and balances of the European Union Member States. Science of The Total Environment, 542, 1078-1093. doi:10.1016/j.scitotenv.2015.08.048Wang, J., You, S., Zong, Y., Træholt, C., Dong, Z. Y., & Zhou, Y. (2019). Flexibility of combined heat and power plants: A review of technologies and operation strategies. Applied Energy, 252, 113445. doi:10.1016/j.apenergy.2019.11344

P-recovery in a pilot-scale struvite crystallisation reactor for source separated urine systems using seawater and magnesium chloride as magnesium sources

[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.This research work was possible thanks to FCC Aqualia participation in INNPRONTA 2011 IISIS IPT-20111023 project (partially funded by The Centre for Industrial Technological Development (CDTI) and supported by the Spanish Ministry of Economy and Competitiveness).Aguado García, D.; Barat, R.; Bouzas Blanco, A.; Seco Torrecillas, A.; Ferrer, J. (2019). P-recovery in a pilot-scale struvite crystallisation reactor for source separated urine systems using seawater and magnesium chloride as magnesium sources. The Science of The Total Environment. 672:88-96. https://doi.org/10.1016/j.scitotenv.2019.03.485S889667

Mesoporous Silica-Based Supports for the Controlled and Targeted Release of Bioactive Molecules in the Gastrointestinal Tract

JFS Special Issue: 75 Years of Advancing Food Science, and Preparing for the Next 75Mesoporous silica particles (MSPs) have attracted increasing interest as supports in the design of controlled delivery materials. Besides their excellent properties as loading supports (that is, large surface area and pore volume), the modification of their external surface with molecular/supramolecular ensembles allows the design of gated MSPs. Delivery systems based on gated MSPs show zero delivery until an adequate stimulus is present and triggers gate opening and the cargo is released. Encapsulation of bioactive molecules in gated MSPs may improve biological stability, facilitate component handling, mask unpleasant sensorial properties, and modulate the bioaccessibility of target molecules along the gastrointestinal tract. These properties make gated MSPs excellent candidates for encapsulating bioactive molecules and their subsequent utilization in the formulation of functional foods. This text highlights the most significant endogenous triggering stimuli that might be applied to design these site-specific delivery systems, as well as the strategies to develop them. Given the novelty of using MSPs in the food sector, the benefits and current potential limitations of employing MSPs in human food have been identified and discussed.Authors gratefully acknowledge the financial support from the Ministerio de Economia y Competitividad (Projects AGL2012-39597-C02-01, AGL2012-39597-C02-02, and MAT2012-38429-C04-01) and the Generalitat Valenciana (project PROME-TEO/2009/016). E.P. and M.R. are grateful to the Ministerio de Ciencia e Innovacion for their grants (AP2008-00620, AP2010-4369).Pérez-Esteve, É.; Ruiz Rico, M.; Martínez-Máñez, R.; Barat Baviera, JM. (2015). Mesoporous Silica-Based Supports for the Controlled and Targeted Release of Bioactive Molecules in the Gastrointestinal Tract. Journal of Food Science. 80(11):E2504-E2516. doi:10.1111/1750-3841.13095SE2504E2516801

Understanding the performance of an AnMBR treating urban wastewater and food waste via model simulation and characterization of the microbial population dynamics

[EN] An anaerobic membrane bioreactor (AnMBR) pilot plant treating kitchen food waste (FW) jointly with urban wastewater was run for 536 days. Different operational conditions were tested varying the sludge retention time (SRT), the hydraulic retention time (HRT) and the penetration factor (PF) of food waste disposers. COD removal efficiency exceeded 90% in all tested conditions. The joint treatment resulted in an almost 3-fold increase in methane production (at 70 days of SRT, 24 h HRT and 80% PF) in comparison with the treatment of urban wastewater only. Mathematical model simulations and Illumina technology were used to obtain in-depth information of this outstanding process performance. Both the PF and SRT factors increased influent biodegradability. The experimental results were accurately reproduced via model simulations modifying only the influent biodegradability. The high SRT and the presence of ground FW in the influent resulted in higher hydrolytic activity. Not only did the Archaea population increase 3-fold but Levilinea genera was also significantly raised. Three new genera characterised by anaerobic fermentation of amino acids (Leptolinea, Aminomonas and Aminobacterium) were among the ten most abundant of the total sequences identified during the joint treatment, indicating an improvement in the hydrolysis step of anaerobic degradation. Influent biodegradability remained at high values when FW addition stopped.This research work has been financially supported by the Generalitat Valenciana (PROMETEO/2012/029 PROJECT), which is gratefully acknowledged.Durán Pinzón, F.; Zamorano -López, N.; Barat, R.; Ferrer, J.; Aguado García, D. (2018). Understanding the performance of an AnMBR treating urban wastewater and food waste via model simulation and characterization of the microbial population dynamics. Process Biochemistry. 67:139-146. https://doi.org/10.1016/j.procbio.2018.02.010S1391466

Nanotechnology in the Development of Novel Functional Foods or their Package. An Overview Based in Patent Analysis

[EN] In recent years nanotechnology has become a significant component in food industry. It is present in all food chain steps, from the design of new ingredients or additives, to the most modern systems of food quality methods or packaging, demonstrating the great potential of this new technology in a sector as traditional as food. However, while interest by industry in nanotechnology increases, the rejection by consumers, concerned about the potential risk, does too. The aim of this review is to evaluate the development of food nanotechnology by means of a patent analysis, highlighting current applications of nanotechnology along the whole food chain and contextualizing this evolution in the social scene.Financial support from the Spanish Government (project MAT2009-14564-C04-01 and AGL2010-20539) and the Generalitat Valencia (project PROMETEO/2009/016) are gratefully acknowledged. E.P. thanks the Ministerio de Educación for a fellowshipPérez-Esteve, É.; Bernardos Bau, A.; Martínez-Máñez, R.; Barat Baviera, JM. (2013). Nanotechnology in the Development of Novel Functional Foods or their Package. An Overview Based in Patent Analysis. Recent Patents on Food, Nutrition and Agriculture. 5(1):35-43. https://doi.org/10.2174/2212798411305010006S35435

Sludge management modeling to enhance P-recovery as struvite in wastewater treatment plants

[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.This work was co-financed by the European Financial Instrument for the Environment (LIFE +) as part of the PHORWater Project (LIFE12 ENV/ES/000441).Martí Ortega, N.; Barat, R.; Seco Torrecillas, A.; Pastor Alcañiz, L.; Bouzas Blanco, A. (2017). Sludge management modeling to enhance P-recovery as struvite in wastewater treatment plants. Journal of Environmental Management. 196:340-346. https://doi.org/10.1016/j.jenvman.2016.12.074S34034619

Effect of ambient temperature variations on an indigenous microalgae-nitrifying bacteria culture dominated by Chlorella

[EN] Two outdoor photobioreactors were operated to evaluate the effect of variable ambient temperature on an indigenous microalgae-nitrifying bacteria culture dominated by Chlorella. Four experiments were carried out in different seasons, maintaining the temperature-controlled PBR at around 25¿°C (by either heating or cooling), while the temperature in the non-temperature-controlled PBR was allowed to vary with the ambient conditions. Temperatures in the range of 15¿30¿°C had no significant effect on the microalgae cultivation performance. However, when the temperature rose to 30¿35¿°C microalgae viability was significantly reduced. Sudden temperature rises triggered AOB growth in the indigenous microalgae culture, which worsened microalgae performance, especially when AOB activity made the system ammonium-limited. Microalgae activity could be recovered after a short temperature peak over 30¿°C once the temperature dropped, but stopped when the temperature was maintained around 28¿30¿°C for several days.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 also received support from the Spanish Ministry of Education, Culture and Sport via a pre-doctoral FPU fellowship to authors J. González-Camejo (FPU14/05082) and S. Aparicio (FPU/15/02595).Gonzalez-Camejo, J.; Aparicio Antón, SE.; Ruano, M.; Borrás, L.; Barat, R.; Ferrer, J. (2019). Effect of ambient temperature variations on an indigenous microalgae-nitrifying bacteria culture dominated by Chlorella. Bioresource Technology. 290:1-10. https://doi.org/10.1016/j.biortech.2019.121788S11029

Implementation of a global P-recovery system in urban wastewater treatment plants

[EN] Current wastewater treatment plants (WWTPs) paradigm is moving towards the so-called water resource recovery facilities in which sewage is considered a source of valuable resources. In particular, urban WWTPs are crucial systems to enhance phosphorus (P) recycling. This paper evaluates the implementation of a P-recovery system in Calahorra WWTP combining the operation of a new sludge line configuration coupled to a struvite crystallisation reactor at demonstration-scale. This new configuration consisted in the elutriation in the gravity thickener of the mixed sludge contained in the mixing chamber in order to reduce the phosphate load to the anaerobic digestion. The results indicated that the P available in the primary sludge overflow was nearly five times more than the obtained for the conventional configuration (1.88 vs. 0.39 gP/kg sludge treated), and the uncontrolled P precipitation inside the anaerobic digester was reduced by 43%. Regarding the total P entering the WWTP, 19% of the total P could be recovered with the new configuration proposed in comparison with 9% in the previous conventional configuration. The average recovery efficiency in the crystallisation plant was 86.9 0.4%, yielding a struvite recovery of 8.0 +/- 0.6 kg/d (0.67 +/- 0.04 kg/m(3) fed to the crystalliser). The potential struvite production with the new configuration would be around 41 kg/d (15 t/y) crystallising the thickener supernatant which could be increased up to around 103 kg/d (38 t/y) treating all the P enriched streams (thickener supernatant and centrate streams). The paper demonstrates that WWTPs can contribute to reduce P scarcity, resulting in environmental and economic benefits. (C) 2019 Elsevier Ltd. All rights reserved.This work was co-financed by the European Financial Instrument for the Environment (LIFE +) as part of the PHORWater Project (LIFE12 ENV/ES/000441). The authors also like to acknowledge the support received from Consorcio de Aguas y Residuos de La Rioja and from EDAR del Cidacos (Calahorra).Bouzas Blanco, A.; Martí Ortega, N.; Grau, S.; Barat, R.; Mangin, D.; Pastor Alcañiz, L. (2019). Implementation of a global P-recovery system in urban wastewater treatment plants. Journal of Cleaner Production. 227:130-140. https://doi.org/10.1016/j.jclepro.2019.04.126S13014022