Kinetics of the anaerobic purification of aerobically prebiotreated olive mill wastewater

Se ha efectuado un estudio cinético del proceso de depuración anaerobia de un alpechín previamente tratado vía aerobia con objeto de eliminar la mayor parte de los compuestos fenólicos responsables de su poder inhibidor. Se utilizan dos reactores anaerobios, uno con soporte Pansil y un Testigo sin relleno, para estudiar la influencia del soporte de inmovilización tanto sobre las constantes biocinéticas como sobre la eficiencia del proceso de digestión anaerobia o biometanización de este alpechín pretratado. A diferencia de lo que ocurre con el alpechín natural, se observa sólo una pequeñísima disminución de las constantes aparentes de velocidad del proceso anaerobio al aumentar la densidad de carga. Por otra parte, no se aprecian fenómenos de inhibición en el proceso de biometanización de este agua residual previamente tratada de forma aerobiaA kinetic study has been carried out on the process of anaerobic purification of an olive mill wastewater pre-treated aerobically to eliminate the greater part of the phenolic compounds responsible for inhibition. Two anaerobic digesters were used, one with Pansil support, and the other a Reference without filling. The aim was to study the influence of the immobilization support both on the biokinetic constants and on the efficiency of the anaerobic digestion process or biomethanization of this pre-treated olive mill wastewater. In contrast to what takes place with natural olive mill wastewater, only a very small decrease in the apparent rate constants of the anaerobic process was observed on increasing load density. At the same time, no inhibition was found in the biomethanization of this aerobically pre-treated wastewate

Biodegradation of phenolic compounds present in oil-mill wastewater

Las aguas residuales de la obtención del aceite de oliva o alpechines son responsables de la mayor contaminación medioambiental de Andalucía por su elevada carga de materia orgánica. Su depuración por biometanización es difícil debido a la actividad antimicrobiana de los compuestos fenólícos. Este tipo de sustancias puede eliminarse en gran parte tratando previamente el alpechín por vía aerobia con microorganismos específicos, después de lo cual la depuración anaerobia tiene lugar sin inhibiciones, siendo la constante de velocidad cinco veces superior a la de antes del pretratamiento. En este trabajo se hace un estudio cualitativo de los fenoles por cromatografía en capa fina y cuantitativo de los fenoles totales, orto- y meta-difenoles, así como de la Demanda Química de Oxígeno del alpechín antes del tratamiento, después del pretratamiento y después de la biometanización. Se ha comprobado también la ausencia de leucoantocianinas que pudieran dar origen a fenoles polimerizadosOil-mill wastewater is the main responsible of the pollution in Andalusian due to high content of organic substances. Its depuration by methanization is difficult because of the antimicrobial activity of phenolic derivatives. These compounds can be drastically reduced by a previous aerobic treatment of the oilmill wastewater with specific microorganisms. After this pretreatment, anaerobic depuration takes place without inhibition, the velocity of the reaction being 5 times higher than before the pretreatment. In this paper a qualitative study of the phenols present in oil-mill wastewater by thin layer chromatography has been done. Beside that, quantitative determination of total phenols, ortoand meta-diphenols as well as Chemical Oxigen Demand (COD) before the treatment, after the pretreatment and after biomethanization have been carried out. Finally, leucoanthocyanins that could originate polymerized phenols have not been foun

Mesophilic anaerobic co-digestion of the organic fraction of municipal solid waste with the liquid fraction from hydrothermal carbonization of sewage sludge

In the present study, the influence of substrate pre-treatment (grinding and sieving) on batch anaerobic digestion of the organic fraction of municipal solid waste (OFMSW) was first assessed, then followed by co-digestion experiments with the liquid fraction from hydrothermal carbonization (LFHTC) of dewatered sewage sludge (DSS). The methane yield of batch anaerobic digestion after grinding and sieving (20 mm diameter) the OFMSW was considerably higher (453 mL CH4 STP g−1 VSadded) than that of untreated OFMSW (285 mL CH4 STP g−1 VSadded). The modified Gompertz model adequately predicted process performance. The maximum methane production rate, Rm, for ground and sieved OFMSW was 2.4 times higher than that of untreated OFMSW. The anaerobic co-digestion of different mixtures of OFMSW and LFHTC of DSS did not increase the methane yield above that of the anaerobic digestion of OFMSW alone, and no synergistic effects were observed. However, the co-digestion of both wastes at a ratio of 75% OFMSW-25% LFHTC provides a practical waste management option. The experimental results were adequately fitted to a first-order kinetic model showing a kinetic constant virtually independent of the percentage of LFHTC (0.52–0.56 d−1) and decreasing slightly for 100% LFHTC (0.44 d−1)The authors wish to express their gratitude to the Spanish MINECO (CTM2016-76564-R) for providing financial support. M. A. de la Rubia received financial support from the Spanish Ministry of Economy and Competitiveness (RYC-2013-12549

Enhancing methane production from the invasive macroalga Rugulopteryx okamurae through anaerobic co-digestion with olive mill solid waste: process performance and kinetic analysis

The biomass valorisation of the invasive brown alga Rugulopteryx okamurae (Dictyotales, Phaeophyceae) is key to curbing the expansion of this invasive macroalga which is generating tonnes of biomass on southern Spain beaches. As a feasible alternative for the biomass management, anaerobic co-digestion is proposed in this study. Although the anaerobic digestion of macroalgae barely produced 177 mL of CH4 g−1 VS, the co-digestion with a C-rich substrate, such as the olive mill solid waste (OMSW, the main waste derived from the two-phase olive oil manufacturing process), improved the anaerobic digestion process. The mixture improved not only the methane yield, but also its biodegradability. The highest biodegradability was found in the mixture 1 R. okamurae—1 OMSW, which improved the biodegradability of the macroalgae by 12.9% and 38.1% for the OMSW. The highest methane yield was observed for the mixture 1 R. okamurae—3 OMSW, improving the methane production of macroalgae alone by 157% and the OMSW methane production by 8.6%. Two mathematical models were used to fit the experimental data of methane production time with the aim of assessing the processes and obtaining the kinetic constants of the anaerobic co-digestion of different combination of R. okamurae and OMSW and both substrates independently. First-order kinetic and the transference function models allowed for appropriately fitting the experimental results of methane production with digestion time. The specific rate constant, k (first-order model) for the mixture 1 R. okamurae- 1.5 OMSW, was 5.1 and 1.3 times higher than that obtained for the mono-digestion of single OMSW and the macroalga, respectively. In the same way, the transference function model revealed that the maximum methane production rate (Rmax) was also found for the mixture 1 R. okamurae—1.5 OMSW (30.4 mL CH4 g−1 VS day−1), which was 1.6 and 2.2 times higher than the corresponding to the mono-digestions of the single OMSW and sole R. okamurae (18.9 and 13.6 mL CH4 g−1 VS day−1), respectively.Ministerio de Ciencia e Innovación PID2020-114975RB-10

Revisiting the Simplicity Constraints and Coherent Intertwiners

In the context of loop quantum gravity and spinfoam models, the simplicity constraints are essential in that they allow to write general relativity as a constrained topological BF theory. In this work, we apply the recently developed U(N) framework for SU(2) intertwiners to the issue of imposing the simplicity constraints to spin network states. More particularly, we focus on solving them on individual intertwiners in the 4d Euclidean theory. We review the standard way of solving the simplicity constraints using coherent intertwiners and we explain how these fit within the U(N) framework. Then we show how these constraints can be written as a closed u(N) algebra and we propose a set of U(N) coherent states that solves all the simplicity constraints weakly for an arbitrary Immirzi parameter.Comment: 28 page

Consumo de nutriente em cordeiros alimentados com torta de dendê.

Objetivou-se determinar o nível ideal da torta de dendê na dieta, por intermédio de consumo. O experimento foi conduzido no aprisco da Escola de Medicina Veterinária da UFBA, Salvador-BA, com duração de 80 dias. Foram utilizados trinta e dois cordeiros de raça Santa Inês, com peso vivo inicial de aproximadamente 22 kg, entre quatro a seis meses de idade. Os tratamentos consistiram de quatro níveis (0; 6,5; 13,0 e 19,5%) de inclusão de torta de dendê na matéria seca da dieta. As dietas foram fornecidas duas vezes ao dia (ás 9 e 16 h), na forma de ração total, em quantidade ajustada para ocorrer 10 a 20% das sobras. Os consumos de matéria seca, de matéria orgânica, de proteína bruta e de carboidratos nãofibrosos seguiram comportamento linear decrescente com adição dos níveis de torta de dendê na dieta (p0,05)

Utilización y tratamiento del alpechín: situación actual y perspectivas en España

The characteristics of olive mill wastewater are set out the viewpoint of their pollutant capacity and the problems arising from their tipping in olive-growing areas. The national administration's solutions for preventing pollutions of surface waters are also stated. Special detail is given to the action taken within a research and development program financed by the Spanish Government and the EEC through the Commission MEDSPA 89 for the technical-economic evaluation of different systems for eliminating and treating olive mill wastewater, in order to determine the feasibility of their introduction at industrial level. At the same time the systems currently under evaluation are described: - Intensification of natural evaporation from olive mill wastewater stored in ponds (two systems). - Physical processes using forced evaporation to eliminate the olive mill wastewater, followed by aerobic biological processes or systems of ultrafiltration and inverse osmosis for final treatment of the condensate (two systems). - Application of physico-chemical processes to eliminate the greater part of the organic components of the olive mill wastewaters and the use of aerobic biological processes or systems of ultrafiltration and inverse osmosis for final treatment of the clarified fraction (three systems). - Biological process for the complete treatment of the olive mill wastewaters by the successive application of processes: bioconversion, biomethanisation, aerobic treatment, and physico-chemical treatment. Treatment yields of the order of 99,6% are achieved, at the same time obtaining by-products of commercial interest (one system).Las características de los alpechines se establecen desde el punto de vista de su capacidad contaminante y de los problemas típicos que surgen en las zonas de cultivo del olivo. También están descritas las soluciones de la administración del Estado para la prevención de la contaminación de aguas de superficie. Se detallan especialmente los puntos de acción incluidos dentro de un programa de Investigación y Desarrollo financiado por el Gobierno Español y la CEE a través de la comisión MEDSPA 89, para la evaluación técnica y económica de diferentes sistemas de eliminación y tratamiento de alpechines, con el fin de determinar la conveniencia de su introducción a nivel industrial. Al mismo tiempo se describen los sistemas actuales sometidos a evaluación: - Intensificación de la evaporación natural de alpechines almacenados en balsas. - Procesos físicos de evaporación forzada para eliminar este agua residual, seguido de procesos biológicos aerobios o sistemas de ultrafiltración y osmosis inversa para el tratamiento final de los condensados (dos sistemas). - Aplicación de procesos físico-químicos para eliminar la mayor parte de la materia orgánica del alpechín, y uso de procesos biológicos aerobios o sistemas de ultrafiltración y osmosis inversa para el tratamiento final de la fracción clarificada (tres sistemas). - Proceso biológico para la depuración integral del alpechín mediante la aplicación sucesiva de los procesos: bioconversión, biometanización, tratamiento aerobio, y tratamiento físico-químico. Se consiguieron rendimientos del orden del 99,6%, con la obtención simultánea de subproductos de interés comercial (un sistema)

Impact of soft-hydrothermal pre-treatments on the olive mill solid waste characteristics and its subsequent amaerobic digestion

The aim of this study was to investigate the effect of a soft-hydrothermal pre-treatment (SHP) on olive mill solid waste (OMSW) and its subsequent anaerobic digestion (AD). OMSW was pre-treated in an autoclave at temperatures of 121 ºC and 133 ºC and excess pressures of 1.1 and 2.1 bars, respectively at heating times of 15, 20 and 30 minutes. The digestibility of pre-treated and untreated OMSW was determined in terms of methane potential through using biochemical methane potentials tests (BMP). An important solubilisation of high valuable compounds such us hydroxytyrosol, and 3,4-dihydroxyphenylglycol was observed after pre-treatments. SHP showed a significant reduction on fiber length and width (p < 0.05). A higher polysaccharides solubilisation was observed in treatment at 121 ºC comparing with that observed at 133 ºC. SHP carried out at 121 ºC, 1.1 bar (30 min) (pre-treatment A1), allowed obtaining the highest methane yield (380 ± 5 mL CH4/g VS), which was 12.3% higher than that obtained for untreated OMSW. Pearson correlation (PEC) and Principal Component Analysis (PCA) were carried out. PEC showed a positive correlation with phenol vanillic acid and PCA grouped pre-treatment A1 with polysaccharides solubilization. The influence of the SHP conditions on the AD of OMSW was assessed through the monitoring of process performance and calculation of kinetic parameters by using the Transference Function model

“And DPSIR begat DAPSI(W)R(M)!” - A unifying framework for marine environmental management

The marine environment is a complex system formed by interactions between ecological structure and functioning, physico-chemical processes and socio-economic systems. An increase in competing marine uses and users requires a holistic approach to marine management which considers the environmental, economic and societal impacts of all activities. If managed sustainably, the marine environment will deliver a range of ecosystem services which lead to benefits for society. In order to understand the complexity of the system, the DPSIR (Driver-Pressure-State-Impact-Response) approach has long been a valuable problem-structuring framework used to assess the causes, consequences and responses to change in a holistic way. Despite DPSIR being used for a long time, there is still confusion over the definition of its terms and so to be appropriate for current marine management, we contend that this confusion needs to be addressed. Our viewpoint advocates that DPSIR should be extended to DAPSI(W)R(M) (pronounced dap-see-worm) in which Drivers of basic human needs require Activities which lead to Pressures. The Pressures are the mechanisms of State change on the natural system which then leads to Impacts (on human Welfare). Those then require Responses (as Measures). Furthermore, because of the complexity of any managed sea area in terms of multiple Activities, there is the need for a linked-DAPSI(W)R(M) framework, and then the connectivity between marine ecosystems and ecosystems in the catchment and further at sea, requires an interlinked, nested-DAPSI(W)R(M) framework to reflect the continuum between adjacent ecosystems. Finally, the unifying framework for integrated marine management is completed by encompassing ecosystem structure and functioning, ecosystem services and societal benefits. Hence, DAPSI(W)R(M) links the socio-ecological system of the effects of changes to the natural system on the human uses and benefits of the marine system. However, to deliver these sustainably in the light of human activities requires a Risk Assessment and Risk Management framework; the ISO-compliant Bow-Tie method is used here as an example. Finally, to secure ecosystem health and economic benefits such as Blue Growth, successful, adaptive and sustainable marine management Responses (as Measures) are delivered using the 10-tenets, a set of facets covering all management disciplines and approaches

Influencia de la concentración de sustrato sobre la cinética del proceso de biometanización del alpechín, en biorreactores de lecho fluidizado con microorganismos inmovilizados

A kinetic study has been made of the anaerobic olive mill wastewater fermentation process in fluid bed bioreactors containing clay supports in suspension, on which the microorganisms responsible for the process have been immobilized. Four concentrations of wastewater have been used (10%, 20%, 40% and 80%) to study the influence of the substrate concentration, and at the same time, of the immobilization support, on the biokinetic constants of the continuous process. The Chen-Hashimoto model of methane production has been applied, obtaining the values of the kinetic parameters μmax and K for each case studied. The values of these parameters decreased considerably with increasing concentration of influent wastewater, though this decrease varied depending on the support used.Se ha efectuado un estudio cinético del proceso de fermentación anaerobia del alpechín en biorreactores de lecho fluidizado que contienen en suspensión soportes de tipo arcilloso sobre los que se han inmovilizado los microorganismos responsables del proceso. Se utilizan cuatro concentraciones de alpechín (10%, 20%, 40% y 80%) para estudiar la influencia de la concentración de sustrato sobre las constantes biocinéticas del proceso en régimen continuo, estudiándose al mismo tiempo la influencia del soporte de inmovilización sobre las mismas. Para ello, se aplica el modelo de Chen-Hashimoto de producción de metano, obteniéndose los valores de los parámetros cinéticos μmax y K, para cada uno de los casos estudiados. Se obtiene una disminución considerable de los valores de estos parámetros al aumentar la concentración de alpechín utilizada como influente, si bien este descenso de las constantes cinéticas varia según el soporte considerado