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

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

PLS-based soft-sensor to predict ammonium concentration evolution in hollow fibre membrane contactors for nitrogen recovery

[EN] Hollow fibre membrane contactors (HFMC) have emerged as a promising technology for nitrogen-recovery that can be implemented in wastewater treatment plants (WWTPs) to promote circular economy. In this process, a hydrophobic membrane allows the transference of free-ammonia across the hollow fibres. During its operation, the ammonium concentration decreases, and real-time measurements would be of great value for process monitoring, optimization and control. Ammonium probes exist, but they are expensive and present noticeably maintenance costs. In this work, results from eight N-recovery experiments performed at different pH values using real supernatant of a full-scale anaerobic digester were analysed in terms of the time-evolution profiles of pH and total ammonium nitrogen (TAN). The pH revealed to carry relevant information related to the TAN concentration, as it decreased in the feed solution due to free ammonia stripping. The pH is an inexpensive-to measure process variable that can be routinely acquired in any WWTP. Therefore, a data-driven soft-sensor has been developed. It uses the pH, its derivative, and the pH increments after each reagent dosing as input signals, to estimate the TAN concentration via PLS. An extended PLS-model incorporating interaction terms, quadratic and cubic forms of the three input variables improved the TAN concentration estimation. The developed soft-sensor was able to accurately reproduce the evolution of TAN concentration (in the range 0-1000 mgNH(4)(+)-N/L with R-2 > 0.97 and RMSE < 40 mg/L) during the HFMC process operation, thus making it possible to monitor the process as well as enabling future development of different control and optimization strategies.This research was financially supported by the Spanish Ministry of Economy and Competitiveness (MINECO projects CTM2014-54980-C2-1/2-R and CTM2017-86751-C2-1/2-R) with the European Regional Development Fund (ERDF) as well as the Universitat Polite`cnica de Vale`ncia via a pre-doctoral FPI fellowship to Guillermo Noriega.Aguado García, D.; Noriega-Hevia, G.; Ferrer, J.; Seco, A.; Serralta Sevilla, J. (2022). PLS-based soft-sensor to predict ammonium concentration evolution in hollow fibre membrane contactors for nitrogen recovery. Journal of Water Process Engineering. 47:1-7. https://doi.org/10.1016/j.jwpe.2022.102735174

Use of rumen microorganisms to boost the anaerobic biodegradability of microalgae

[EN] A laboratory bioreactor using rumen microorganisms to treat Scenedesmus spp. biomass was operated for 190 days. At first the bioreactor operated as a Rumen-like Fermenter (RF) with a Sludge Retention Time (SRT) of 7 days. The RF was subsequently transformed into an anaerobic digestion system including two configurations: continuously-stirred tank reactor and anaerobic membrane bioreactor in which different SRT values of up to 100 days were assessed. Methane production peaked at 214 mL CH4 g&#8722;1 CODIn with a SRT of 100 days. COD removal and BDP peaked at above 70% and 60%, respectively, at the highest SRT, with no pre-treatment prior to microalgae digestion. The waste sludge production dropped to 0.133 mg VSS mg&#8722;1 CODIn after a SRT of 100 days.This work was funded by the Spanish Ministry of Economy and Competitiveness with the support from the European Commission through the European Regional Development Funds (MINECO, CTM2011-28595-C02-01 and CTM2011-28595-C02-02), which are gratefully acknowledged. The authors would also express their gratitude to the Education, Invetigation, Culture and Sports Council from the Valencian Generality for the Post-Doctoral fellowship awarded to Juan Bautista Gimenez Garcia (APOSTD/2016/104). The authors are thankful to Ion Perez Baena (Universitat Politecnica de Valencia, Institut de Ciencia i Tecnologia Animal) for kindly providing the ruminal fluid used in this study.Gimenez, JB.; Aguado García, D.; Bouzas, A.; Ferrer, J.; Seco Torrecillas, A. (2017). Use of rumen microorganisms to boost the anaerobic biodegradability of microalgae. Algal Research. 24:309-316. https://doi.org/10.1016/j.algal.2017.04.0033093162

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

Uso de ingeniería inversa para hacer frente al malware

Este artículo es producto del proyecto de investigación “Cyber Security Architecture for Incident Management” desarrollado en la Escuela Colombiana de Ingeniería Julio Garavito en el año 2018.Introducción: La ingeniería inversa permite deconstruir y extraer conocimiento de objetos. El uso de la inge-niería inversa en el análisis de malware es extremadamente útil para comprender las funcionalidades y los propósitos de una muestra sospechosa.Métodos: Este artículo utiliza Radare, la cual es una de las herramientas de código abierto más populares para ingeniería inversa con el objetivo de hacer frente a las amenazas de malware.Resultados: Se presenta un caso de uso relacionado al análisis de malware anti-sandbox, de forma que sea posible analizar el comportamiento de la muestra utilizando una sandbox. Además, se presenta otro caso de uso en el que se desarrolla un análisis en profundidad de una aplicación maliciosa de Android dirigida a la audiencia de un evento popular (Copa Mundial de la FIFA 2018), que permite demostrar la relevancia de las técnicas de ingeniería inversa en las estrategias de protección al usuario final.Conclusiones: Este artículo muestra cómo los resultados de un proceso de ingeniería inversa se pueden inte-grar con reglas Yara, lo que permite detectar malware, y también muestra una alternativa para generar auto-máticamente reglas Yara a través del generador yarGen.Originalidad: El uso de soluciones de ingeniería inversa de código abierto por parte de las agencias de seguri-dad del estado no ha sido discutido anteriormente, lo que hace de este artículo un elemento notable de apoyo hacia la modernización de las fuerzas militares.Limitación: Se comparten diferentes enfoques y perspectivas sobre las limitaciones en el uso de ingeniería inversa por parte de las agencias de seguridad del estado.This paper is a product of the research Project “Cyber Security Architecture for Incident Management” develo-ped in the Colombian School of Engineering Julio Garavito in the year 2018.Introduction: Reverse engineering involves deconstructing and extracting knowledge about objects. The use of reverse engineering in malware analysis is extremely useful in understanding the functionalities and purposes of a suspicious sample.Methods: This paper makes use of Radare which is one of the most popular open source tools for reverse engineering, with the aim of dealing with malware. Results: A use case related to hacking of anti-sandbox malware is presented, in such a way that it is possible to analyze the behavior of the sample using a sandbox. Additionally, another use case is presented, where an in-depth analysis of a malicious Android application aimed to the audience of a popular event (FIFA World Cup 2018) is developed, making it possible to demonstrate the relevance of reverse engineering techniques in end-user protection strategies. Conclusions: This paper shows how the results of a reverse engineering process can be integrated with Yara rules, allowing for the detection of malware on the fly, and it also shows an alternative to automatically gene-rating Yara rules through the yarGen generator. Originality: Use of Open Source reversing solutions by Colombian Law Enforcement Agencies has not been discussed previously, making this paper a notable element toward the modernization of the military forces.Limitation: Different approaches and perspectives about the limitations in the use of reverse engineering by Law Enforcement Agencies are also shared.Este artigo é produto do projeto de pesquisa “Cyber Security Architecture for Incident Management” desenvol-vido na Escuela Colombiana de Ingeniería Julio Garavito em 2018.Introdução: a engenharia reversa permite desconstruir e extrair conhecimento de objetos. O uso da engenharia reversa na análise de malware é extremamente útil para compreender as funcionalidades e os propósitos de uma amostra suspeita.Métodos: para isso, utiliza-se Radare, que é uma das ferramentas de código aberto mais populares para en-genharia reversa com o objetivo de enfrentar as ameaças de malware.Resultados: apresenta-se um caso de uso relacionado à análise de malware anti-sandbox, de forma que seja possível analisar o comportamento da amostra utilizando uma sandbox. Além disso, apresenta-se outro caso de uso em que se desenvolve uma análise em profundidade de uma aplicação maliciosa de Android dirigida à audiência de um evento popular (Copa do Mundo da FIFA 2018), que permite demonstrar a relevância das técnicas de engenharia reversa nas estratégias de proteção do usuário final.Conclusões: este artigo mostra como os resultados de um processo de engenharia reversa podem ser integra-dos com regras Yara, o que permite detectar malware, e também mostra uma alternativa para gerar automati-camente regras Yara por meio do gerador yarGen.Originalidade: o uso de soluções de engenharia reversa de código aberto por parte das agências de segurança do Estado não tem sido discutido anteriormente, o que torna este estudo um elemento notável de apoio à modernização das forças militares.Limitação: compartilham-se diferentes abordagens e perspectivas sobre as limitações no uso de engenharia reversa por parte das agências de segurança do Estad

Thermophilic anaerobic conversion of raw microalgae: Microbial community diversity in high solids retention systems

[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.This research work has been supported by the Spanish Ministry of Economy and Competitiveness (MINECO, Project CTM2011-28595-C02-02) jointly with the European Regional Development Fund (ERDF), which are gratefully acknowledged. The authors are thankful to Fernando Fdz-Polanco research team (University of Valladolid, Spain) for providing the thermophilic sludge from their pilot plant to inoculate the bioreactor and Llúcia Martínez and Giusseppe D'Aria from FISABIO sequencing service (Valencia, Spain) for their technical support during the Illumina sequencing design.Zamorano-López, N.; Greses-Huerta, S.; Aguado García, D.; Seco Torrecillas, A.; Borrás Falomir, L. (2019). Thermophilic anaerobic conversion of raw microalgae: Microbial community diversity in high solids retention systems. Algal Research. 41:1-9. https://doi.org/10.1016/j.algal.2019.101533S194

Acclimatised rumen culture for raw microalgae conversion into biogas: Linking microbial community structure and operational parameters in anaerobic membrane bioreactors (AnMBR)

[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.This research work has been supported by the Spanish Ministry of Economy and Competitiveness (MINECO, Projects CTM2011-28595-C02-01 and CTM2011-28595-C02-02), which is gratefully acknowledged. The Education, Investigation, Culture and sports Council from the Valencian Generality for the Post-Doctoral fellowship of the third co-author is also acknowledged (APOSTD/2016/104). The authors are thankful to Ion Pérez Baena from the Universitat Politècnica de Valencia, Institut de Ciència I Tecnología Animal for gently providing the ruminal fluid use in this work.Zamorano-López, N.; Borrás Falomir, L.; Giménez, JB.; Seco Torrecillas, A.; Aguado García, D. (2019). Acclimatised rumen culture for raw microalgae conversion into biogas: Linking microbial community structure and operational parameters in anaerobic membrane bioreactors (AnMBR). Bioresource Technology. 290:1-9. https://doi.org/10.1016/j.biortech.2019.121787S1929

Sources, Mobility, Reactivity, and Remediation of Heavy Metal(loid) Pollution: A Review

[EN] Heavy metal(loid)s are a group of elements present commonly in the environment, including Cr, Ni, Cu, Zn, Cd, Hg, Pb, and As elements, among others. While these elements could have their origins in natural sources, anthropogenic activities, such as mining, agriculture, industry, etc., are also responsible for enhancing the concentration of these elements in the ecosystems up to undesirable levels. A few of these metal(loid)s serve as necessary micronutrients for life, while the others are extremely harmful and might affect the entire trophic chain upon entering the natural ecosystems due to their mobility and toxicity characteristics. Most of these heavy metal(loid) pollutants are already recognized for their harmful effects; nevertheless, their environmental control encounters obstruction due to various factors. In this context, the present report details the key points regarding the anthropogenic sources of heavy metal(loid) pollution, which are increasing rapidly with time due to the emerging industry practices and processes, the elements causing this kind of pollution, and the physicochemical processes of these elements occurring in the environment¿air interface, soil, and water-air interface. These elements exert a severe impact on the environment, which could be mitigated through the development and application of various remediation techniques. Therefore, the present report concludes with a final discussion on the various remediation treatments currently available for reducing the heavy metal(loid) contamination level in both water and soil.Martínez-Guijarro, MR.; Paches Giner, MAV.; Romero Gil, I.; Aguado García, D. (2021). Sources, Mobility, Reactivity, and Remediation of Heavy Metal(loid) Pollution: A Review. Advances in Environmental and Engineering Research. 2(4):1-30. https://doi.org/10.21926/aeer.2104033S1302

Enrichment and contamination level of trace metals in theMediterranean marine sediments of Spain

[EN] Coastal ecosystems are heavily polluted by human activities. These pollutants reach the aquatic environment and accumulate in the sediment. Among the chemical pollutants, metals represent a notable hazard since they are not biodegradable and have the capability to bioaccumulate, resulting in toxic effects in both the short and long term. In this study, the content of metals and As in marine sediments of the Spanish Mediterranean coast was determined. A total of four annual sampling campaigns were carried out along the Valencian Community coastline, where the presence of eight trace elements (Cr, Cd, Ni, Pb, Cu, Hg, Zn and As) was determined. In this area, the presence of the contaminants is due to both natural and anthropogenic sources. The results obtained allowed, first, to establish nearness Reference Values of the area under study, second, to use several pollution indices (Contamination Factor, Enrichment Factor, Geoaccumulation Factor, Nemerow Pollution Index, and Modified Pollution Index) to determine contamination levels in the area, and finally to select the best index to apply in this coastal zone. The best indices to use in this region are EF and MPI since both take into consideration the natural contributions of the elements studied. The results revealed that according to the index used only two studied zones are classified as Heavily and Severely polluted. The remaining zones (between 25 and 29%) were classified as Moderately or Moderately to Heavily polluted and most of the zones (63% to 100%) were classified as Unpolluted/Low Polluted and Unpolluted/Slightly Polluted. The outcomes obtained with this work indicate that in general, the Valencian coast does not present significant levels of pollution due to the studied trace elements.Martínez-Guijarro, MR.; Paches Giner, MAV.; Romero Gil, I.; Aguado García, D. (2019). Enrichment and contamination level of trace metals in theMediterranean marine sediments of Spain. The Science of The Total Environment. 693. https://doi.org/10.1016/j.scitotenv.2019.07.372S69