Evaluation of forward osmosis and low-pressure reverse osmosis with a tubular membrane for the concentration of municipal lwastewater and the production of biogas

Producción CientíficaCurrently, freshwater scarcity is one of the main issues that the world population has to face. To address this issue, new wastewater treatment technologies have been developed such as membrane processes. Among them, due to the energy disadvantages of pressure-driven membrane processes, Forward Osmosis (FO) and Low-Pressure Reverse Osmosis (LPRO) have been introduced as promising alternatives. In this study, the behavior of a 2.3 m2 tubular membrane TFO-D90 when working with municipal wastewater has been studied. Its performances have been evaluated and compared in two operating modes such as FO and LPRO. Parameters such as fouling, flow rates, water flux, draw solution concentration, organic matter concentration, as well as its recovery have been studied. In addition, the biogas production capacity has been evaluated with the concentrated municipal wastewater obtained from each process. The results of this study indicate that the membrane can work in both processes (FO and LPRO) but, from the energy and productivity point of view, FO is considered more appropriate mainly due to its lower fouling level. This research may offer a new point of view on low-energy and energy recovery wastewater treatment and the applicability of FO and LPRO for wastewater concentration.Junta de Castilla y León y Fondo Europeo de Desarrollo Regional (FEDER) - (grant CLU 2017-09, CL-EI-2021-07, VA088G19, and UIC 082 and UIC 334)Ministerio de Ciencia e Innovación - (project PID2019-109403RB-C21/AEI/10.13039/501100011033

Analysis of the energy flow in a municipal wastewater treatment plant based on a supercritical water oxidation reactor coupled to a gas turbine

Producción CientíficaBiological municipal wastewater treatments lead to high sludge generation and long retention times, and the possibilities for recovery of the energy content of the input waste stream are very limited due to the low operating temperature. As an alternative, we propose a sequence of exclusively physicochemical, non-biological stages that avoid sludge production, while producing high-grade energy outflows favoring recovery, all in shorter times. Ultrafiltration and evaporation units provide a front-end concentration block, while a supercritical water oxidation reactor serves as the main treatment unit. A new approach for energy recovery from the effluent of the reactor is proposed, based on its injection in a gas turbine, which presents advantages over simpler direct utilization methods from operational and efficiency points of view. A process layout and a numerical simulation to assess this proposal have been developed. Results show that the model process, characterized with proven operating parameters, found a range of feasible solutions to the treatment problem with similar energy costs, at a fast speed, without sludge production, while co-generating the municipality’s average electricity consumption.Ministerio de Ciencia e Innovación - (Grant RTI2018- 097456-B-100

Ecological risk evaluation and removal of emerging pollutants in urban wastewater by a hollow fiber forward osmosis membrane

Producción CientíficaForward osmosis (FO) is a promising technology for the treatment of urban wastewater. FO can produce high-quality effluents and preconcentrate urban wastewater for subsequent anaerobic treatment. This membrane technology makes it possible to eliminate the pollutants present in urban wastewater, which can cause adverse effects in the ecosystem even at low concentrations. In this study, a 0.6 m2 hollow fiber aquaporin forward osmosis membrane was used for the treatment of urban wastewater from the Valladolid wastewater treatment plant (WWTP). A total of 51 Contaminants of Emerging Concern (CECs) were investigated, of which 18 were found in the target urban wastewater. They were quantified, and their ecotoxicological risk impact was evaluated. Different salts with different concentrations were tested as draw solutions to evaluate the membrane performances when working with pretreated urban wastewater. NaCl was found to be the most appropriate salt since it leads to higher permeate fluxes and lower reverse saline fluxes. The membrane can eliminate or significantly reduce the pollutants present in the studied urban wastewater, producing water without ecotoxicological risk or essentially free of pollutants. In all cases, good recovery was achieved, which increased with molecular weight, although chemical and electrostatic interactions also played a role.Ministerio de Ciencia e Innovación/Agencia Estatal de Investigación (AEI)/10.13039/501100011033 - (project PID2019-109403RBC21

Ectoines production from biogas in pilot bubble column bioreactors and their subsequent extraction via bio-milking

Producción CientíficaDespite the potential of biogas from waste/wastewater treatment as a renewable energy source, the presence of pollutants and the rapid decrease in the levelized cost of solar and wind power constrain the use of biogas for energy generation. Biogas conversion into ectoine, one of the most valuable bioproducts (1000 €/kg), constitutes a new strategy to promote a competitive biogas market. The potential for a stand-alone 20 L bubble column bioreactor operating at 6% NaCl and two 10 L interconnected bioreactors (at 0 and 6% NaCl, respectively) for ectoine production from biogas was comparatively assessed. The stand-alone reactor supported the best process performance due to its highest robustness and efficiency for ectoine accumulation (20–52 mgectoine/gVSS) and CH4 degradation (up to 84%). The increase in N availability and internal gas recirculation did not enhance ectoine synthesis. However, a 2-fold increase in the internal gas recirculation resulted in an approximately 1.3-fold increase in CH4 removal efficiency. Finally, the recovery of ectoine through bacterial bio-milking resulted in efficiencies of >70% without any negative impact of methanotrophic cell recycling to the bioreactors on CH4 biodegradation or ectoine synthesis.European Union's Horizon 2020 research and innovation program under grant agreement No 837998European Union's Horizon 2020 research and innovation program and the Bio-based Industries ConsortiumJunta de Castilla y León y EU-FEDER (CLU 2017–09, CL-EI-2021–07, UIC 315

Study of the rejection of contaminants of emerging concern by a biomimetic aquaporin hollow fiber forward osmosis membrane

Producción CientíficaForward osmosis (FO) plays an increasingly important role in membrane processes because of its advantages compared to traditional pressure-driven membrane processes. There are different types of water-selective FO membranes. In this study, a biomimetic hollow fiber module comprising an active layer of polyamide thin film composite (TFC) with integrated aquaporin proteins and an effective area of 0.6 m2 is used to study the rejection of 24 Contaminants of Emerging Concern (CECs). The rejections obtained for all the contaminants studied were higher than 93 % and for 19 of them rejections of up to 99 % were reached. It was observed that although all the tested compounds showed rejections very close to 100 %, they were not completely recovered in the feed solution which makes the retention within the membrane an important factor to be considered. Hence, two membrane rinses were necessary after each membrane operation to completely recover each contaminant. The results were analyzed considering the physicochemical properties (molecular weight, charge and hydrophobicity) of the contaminants.Junta de Castilla y León - Fondo Europeo de Desarrollo Regional (projects NFRARED-2018-UVA3, CLU 2017-09, VA088G19, UIC 071 and UIC 0829)Ministerio de Ciencia, Innovación y Universidades (project PID2019-109403RB-C21

XII reunión de la Mesa Española de Tratamiento de Aguas Residuales

Desde 1980 el Grupo de Tecnología Ambiental del Departamento de Ingeniería Química y Tecnología del Medio Ambiente de la Universidad de Valladolid trabaja en el desarrollo de tecnologías eficientes, económicas y sostenibles de tratamiento, gestión y valorización de contaminantes, tanto para aguas residuales como para gases y residuos sólidos. La investigación del grupo se ha dirigido principalmente al desarrollo de procesos biológicos, empleando técnicas de biología molecular para su caracterización y seguimiento. Actualmente, el grupo está formado por 10 investigadores senior, 6 post-docs y 17 doctorandos. En los últimos diez años, ha participado en 40 proyectos con financiación pública y 51 con financiación privada, con una producción científica de 27 Tesis Doctorales defendidas, 207 publicaciones JCR, 222 congresos Internacionales y 6 patentes, trabajando en diversas líneas de investigación (http://envtech.uva.es/): - Procesos anaerobios de tratamiento, incluyendo la aplicación de tecnologías de membranas, el estudio de procesos microaeróbicos para la eliminación de H2S, o el enriquecimiento de biogás por conversión biológica de CO2 y H2. - Tratamiento de aguas residuales, con estudios microbiológicos de los procesos de eliminación de nutrientes, análisis y tratamiento de microcontaminantes y combinando eliminación de nutrientes, minimización de fangos y optimización energética. - Tratamiento, minimización y valorización de fangos, aplicando pretratamientos como la explosión de vapor o la hidrólisis térmica para incrementar la producción de biogás. - Tratamiento biológico de aguas residuales mediante consorcios de algas y bacterias, acoplando procesos de oxidación de materia orgánica, eliminación de nutrientes, enriquecimiento de biogás o captura de CO2. - Tratamiento biológico de gases de efecto invernadero, olores y compuestos orgánicos volátiles mediante biorreactores de alta transferencia de materia - Valorización de residuos lignocelulósicos y de biomasa algal para producir bioenergía en forma de alcoholes o de biogás, aprovechando la fracción proteica como biofertilizantes o alimentación animal

Vídeos para apoyo al aprendizaje en las áreas de Ingeniería Química y Tecnologías del Medio Ambiente

Elaboración de screencasts/podcasts (vídeos que resultan de la grabación de imagen de pantalla y el sonido de las explicaciones del docente) para substituir a una parte substancial de las explicaciones teóricas que tradicionalmente se llevan a cabo en el aula. Se han elaborado vídeos de apoyo para la docencia teórica y/o práctica de dos asignaturas del Máster de Ingeniería Química, y bloques de clases teóricas de asignaturas de primer y cuarto curso del Grado Ingeniería Química y se han empleado en la docencia. Se han elaborado también numerosos vídeos con temática relacionada con la docencia del Departamento por los participantes no encuadrados en el desarrollo de medios para las asignaturas citadas.Departamento de Ingeniería Química y Tecnología del Medio AmbienteVídeos elaborados en el PROYECTO DE INNOVACIÓN DOCENTE 2020/2021 Ref:089 "Vídeos para apoyo al aprendizaje en las áreas de Ingeniería Química y Tecnologías del Medio Ambiente