Estudo de biodegradabilidade de efluentes agropecu?rios e agroindustriais em processos de co-digest?o anaer?bia

Disserta??o de mestrado em Gest?o Ambiental e Ordenamento do Territ?rio, apresentada ? Escola Superior Agr?ria do Instituto Polit?cnico de Viana do CasteloPerante as crescentes preocupa??es com o aumento da procura energ?tica e as altera??es clim?ticas, aliadas ? grande quantidade de res?duos org?nicos gerados por atividades antropog?nicas, que ainda carecem de tratamento adequado devido ao seu impacte no meio ambiente, torna-se necess?rio o desenvolvimento de tecnologias limpas para tratamento de res?duos tendo em vista a sua valoriza??o energ?tica. Neste contexto, a digest?o anaer?bia para a produ??o de biog?s mostra-se como uma alternativa vantajosa para o tratamento de res?duos e efluentes agropecu?rios e agroindustriais. O objetivo deste estudo consiste em contribuir para o desenvolvimento e otimiza??o de uma solu??o integrada para tratamento de ?guas residuais e res?duos agr?colas e agroindustriais com vistas a valoriza??o energ?tica. Assim, a codigest?o anaer?bia de diferentes substratos, chorume de bovinos, efluentes vin?colas e lamas de esta??o de tratamento de ?guas residuais foi investigada. Este estudo permitiu concluir que a co-digest?o anaer?bia de res?duos e efluentes agro-pecu?rios e agroindustriais, com vistas a valoriza??o energ?tica, afigura-se como uma tecnologia vi?vel visto que os resultados demonstraram a melhoria do processo em termos de: i) equil?brio entre carbono e azoto; ii) da CQOt removida; iii) da produ??o te?rica de biog?s e iv) das taxas de biodegradabilidade da mat?ria org?nica. Em suma, pretende-se, com os resultados obtidos no presente estudo, contribuir para aumentar o conhecimento t?cnico e cient?fico no dom?nio da (co)digest?o anaer?bia de res?duos e efluentes agropecu?rios e agroindustriais que, pela sua complexidade e potencial impacte ambiental, carecem de maior controlo, tendo em vista o desenvolvimento de uma solu??o integrada que possa responder, por um lado, ? valoriza??o deste tipo de res?duos e, por outro lado, ao quadro legal e ?s pol?ticas de ordenamento do territ?rio.In addiction to the growing concern with increasing energy demand and climate change, combined with the large amount of organic waste generated by anthropogenic activities, which still lack proper treatment due to their impact on the environment, it becomes necessary to develop clean technologies for treating waste with a view to energy recovery. In this context, anaerobic digestion for biogas production proves to be an advantageous alternative for the treatment of agricultural and agro-industrial wastes and wastewater. The aim of this study is to contribute to the development and optimization of an integrated solution for wastewater treatment and agricultural and agro-industrial waste with a view to energy recovery. Thus, the anaerobic codigestion of different substrates, cattle manure, sewage wineries and municipal sewage sludge was investigated. This study found that anaerobic co-digestion of agricultural and agroindustrial wastes and wastewater, for the purposes of the energy recovery, it appears as a viable technology since the results demonstrated the efficiency of the process in terms of: i) balance carbon and nitrogen; ii) the removed CQOt; iii) the theoretical production of biogas i) the organic matter degradation rates. In short, it is intended, with the results obtained in this study contribute to increasing the scientific and technical knowledge in the field of (co) anaerobic digestion of agricultural and agro-industrial wastes and wastewater, that due to the complexity and potential environmental impact, lack greater control, with a view to developing an integrated solution that can respond, on the one hand, the appreciation of this type of waste and, on the other hand, the legal framework and regional planning policies

Extração de taninos de Acacia sp. com potencial uso na coagulação: um contributo para a bioeconomia

Coagulation-flocculation is one of the most important steps in water treatment. In Water Treatment Plants, pre-polymerized inorganic coagulants are traditionally used; however, recent studies have shown the potential of condensed tannins for the production of natural coagulants as an alternative to chemical coagulants. In this context, the present work intends to highlight the importance of the development of nature-based solutions that can be alternative to conventional processes, due to the environmental, social and economic benefits they can provide. The study focused on optimizing condensed tannin extraction process from Acacia dealbata barks, as a strategy for valuing forest residues, promoting the territory bioeconomy and sustainability. In the tested extraction conditions, the best yield was obtained at a temperature of 40 oC, using 50% ethanol (v/v) as the solvent, without stirring and an extraction time of 30 min. The highest concentrations of condensed tannins and phenolic compounds were observed in samples of Acacia sp. with higher vegetative development (trunk perimeter of 20 cm), corresponding to 246,2 ± 9,4 miligrams per gram of dry extract (mg ges-1) and 706,2 ± 27,2 mg ges-1, respectively.Este trabalho foi desenvolvido no âmbito do projeto TECH - Tecnologia, Ambiente, Criatividade e Saúde, Norte-01-0145-FEDER-000043, cofinanciado pelo Programa Operacional Regional do Norte (NORTE 2020), através do Portugal 2020 e do Fundo Europeu de Desenvolvimento Regional (FEDER). Leonel Nunes foi apoiado pela proMetheus - Unidade de Investigação & Desenvolvimento em Materiais, Energia e Ambiente para a Sustentabilidade- UIDP/05975/2020, financiado por fundos nacionais através de FCT — Fundação para a Ciência e Tecnologia.info:eu-repo/semantics/publishedVersio

Spatially explicit model for anaerobic co‐digestion facilities location and pre‐dimensioning considering spatial distribution of resource supply and biogas yield in northwest Portugal

The high volumes of animal manure and sewage sludge, as a consequence of the development of intensive and specialized cattle dairy farms in peri-urban areas, pose challenges to local environmental quality and demands for systems innovation. Besides these negative impacts, energy recovery from biogas produced in anaerobic co-digestion processes should contribute to local sustainable development. This research considers technical data obtained from the optimization of biomethanization processes using sewage sludge and cattle manure liquid fraction, aiming to develop a spatially explicit model including multicriteria evaluation and an analytical hierarchy process to locate biogas production facilities, allocate energy resources and consider biogas unit pre-dimensioning analysis. According to the biophysical conditions and socioeconomic dynamics of the study area (Vila do Conde, Northwest Portugal), a spatially explicit model using multicriteria and multiobjective techniques allowed the definition of suitable locations, as well as the allocation of resources and support pre-dimensioning of biogas facilities. A p-median model allowed us to allocate resources and pre-dimensioning biogas facilities according to distance and accessibility elements. The results indicate: (i) the location of areas with adequate environmental conditions and socioeconomic suitability advantages to install biogas production facilities, and (ii) the ability to compare the options of centralized or distributed location alternatives and associated pre-dimensioning.This research was funded by the Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq Brazil), grant number GDE 201469/2014‐6.info:eu-repo/semantics/publishedVersio

Combined pretreatment by ultrasound and struvite precipitation of raw substrates: a strategy to overcome C/N ratio unbalance in nitrogen-rich anaerobic co-digestion systems

The present study aimed to optimize the struvite chemical precipitation process in nitrogen-rich anaerobic co-digestion systems. Struvite precipitation experiments were carried out using a mixture of cattle slurry liquid fraction and sewage sludge, with and without ultrasound pretreatment. Marine salt or MgCl2 were used as magnesium source in NH4+:Mg2+ stoichiometric proportions of 1:1.5 and 1:3. Under the tested conditions, ammonium nitrogen and orthophosphate were removed from the mixed liquor with a maximum observed efficiency of 43% and 92%, respectively, when the ultrasound treatment was applied prior to struvite precipitation, using MgCl2 as source of magnesium (NH4+:Mg2+ of 1:3). The operating time was 40 min. Different pretreatments were tested prior to the biomethanization experiments, struvite precipitation, ultrasound, or a combination of both pretreatments. The application of ultrasound (with an energy input of 218 kJ L?1) and struvite precipitation (NH4+:Mg2+ of 1:3) increased the methane content in the biogas by 82% and reduced hydraulic retention time by 28%, when compared to the anaerobic co-digestion assays without pretreatment. The hydrolytic pretreatment increased the bioavailability of nitrogen by 5%, thus enhancing the removal efficiency of ammonium nitrogen by 20%. Consequently, an increase in the carbon to nitrogen ratio was observed, favoring the methanogenesis process.This research was funded by the Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq—Brazil) grant number GDE 201469/2014-6, which is gratefully acknowledged.info:eu-repo/semantics/publishedVersio

Spatially explicit model for anaerobic co-digestion facilities location and pre-dimensioning considering spatial distribution of resource supply and biogas yield in Northwest Portugal

The high volumes of animal manure and sewage sludge, as a consequence of the development of intensive and specialized cattle dairy farms in peri-urban areas, pose challenges to local environmental quality and demands for systems innovation. Besides these negative impacts, energy recovery from biogas produced in anaerobic co-digestion processes should contribute to local sustainable development. This research considers technical data obtained from the optimization of biomethanization processes using sewage sludge and cattle manure liquid fraction, aiming to develop a spatially explicit model including multicriteria evaluation and an analytical hierarchy process to locate biogas production facilities, allocate energy resources and consider biogas unit pre-dimensioning analysis. According to the biophysical conditions and socioeconomic dynamics of the study area (Vila do Conde, Northwest Portugal), a spatially explicit model using multicriteria and multiobjective techniques allowed the definition of suitable locations, as well as the allocation of resources and support pre-dimensioning of biogas facilities. A p-median model allowed us to allocate resources and pre-dimensioning biogas facilities according to distance and accessibility elements. The results indicate: (i) the location of areas with adequate environmental conditions and socioeconomic suitability advantages to install biogas production facilities, and (ii) the ability to compare the options of centralized or distributed location alternatives and associated pre-dimensioninginfo:eu-repo/semantics/publishedVersio