En los últimos años, el concepto de Soluciones basadas en la Naturaleza (SbN) ha ganado reconocimiento internacional como herramienta para contribuir al desarrollo sostenible. Esto ha venido motivado por una mayor concreción y definición del concepto y una serie de acuerdos internacionales. No obstante, su aplicación en los países sigue siendo escasa. Concretamente, en el sector hídrico siguen siendo preferidas otras soluciones de infraestructura gris consideradas más eficientes para hacer frente a los retos de la gestión de la cantidad, calidad y variabilidad del agua. Así, las SbN para la gestión del agua todavía se enfrentan a varios desafíos que limitan su implementación. La Unión Europea ha puesto en marcha una serie de actuaciones para tratar de resolver estos desafíos: estrategias de acción, normativa y una serie de programas de financiación enfocados en la investigación e innovación mediante el diseño e implementación de proyectos de SbN. | In recent years, the concept of Nature-based Solutions (NBS) seems to have gained international recognition as a potential tool to contribute to sustainable development. This has been motivated by a further specification and concretion of the concept and the creation of several international agreements. However, its implementation at country level remains weak. In the water sector in particular, other grey infrastructure solutions that are considered more efficient in addressing the challenges of managing water quantity, quality and variability are still preferred. Thus, NBS for water management still face several challenges that limit their implementation. The European Union has launched numerous actions to address these challenges: action strategies, regulations and a series of funding programmes focused on research and innovation through the design and implementation of NBS projects.

Soluções baseadas na natureza (SBN), especialmente associadas a esquemas de pagamentos por serviços ambientais (PSA), são uma temática emergente no planejamento de recursos hídricos. Assim, a presente pesquisa objetivou contribuir para melhorar o entendimento de como SBN podem ser desenvolvidas no planejamento de longo prazo dos sistemas hídricos que abastecem cidades. Buscou-se responder (1) como identificar a melhor estratégia para expandir um conjunto de SBN em um dado sistema hídrico e (2) como estimar a relação de custo e benefício do desenvolvimento de um conjunto de SBN. A pesquisa obteve êxito em seus objetivos pois foi desenvolvido um metamodelo que integra modelos de simulação com otimização por programação dinâmica. Esses modelos foram concebidos, assim como seus parâmetros, com base no que sugerem estudos de caso, estudos experimentais e estudos observacionais encontrados na literatura. A função objetivo da otimização consistiu em identificar a rota de expansão que minimiza, ao longo do horizonte de planejamento, o custo total do sistema hídrico, que foi considerado a soma do custo da escassez, custo de tratamento e custo de expansão de SBN. O benefício da expansão de SBN foi concebido como a redução no custo total em relação ao cenário de inação. A melhor estratégia de expansão foi entendida por aquela que otimiza temporalmente as vantagens de cada SBN em relação às pressões apresentadas pelo cenário de futuro. que pastagens com terraços consistiriam na SBN mais indicada para a melhoria da disponibilidade de água, enquanto que o reflorestamento seria mais adequado para a melhoria da qualidade de água. Ainda assim, os resultados apontaram que a expansão de SBN em larga escala sobre os sistemas hídricos responsáveis pelo abastecimento de metrópoles seria inviável economicamente quando avaliado os custos e benefícios diretos. Tais resultados deixaram evidente que os programas de PSA e similares observados na prática no Brasil atuam sobre áreas pelo menos dez vezes menores que as necessárias para produzir impactos perceptíveis sobre a diponibilidade de água de grandes sistemas hídricos, que em geral ocupam centenas de quilômetros quadrados. | Nature-based solutions (NBS), especially associated with payment schemes for environmental services (PES), are an emerging issue in water resource planning. Thus, this research aimed to contribute to improving the understanding of how NBS can be developed in the long-term planning of water systems that supply cities. We sought to answer (1) how to identify the best strategy to expand a set of NBS in a given water system and (2) how to estimate the cost and benefit ratio of developing a set of NBS. The research was successful in its objectives because a metamodel was developed that integrates simulation models with optimization by dynamic programming. These models were conceived, as well as their parameters, based on what case studies, experimental studies and observational studies found in the literature suggest. The objective function of the optimization was to identify the expansion path that minimizes, over the planning horizon, the total cost of the water system, which was considered the sum of the scarcity cost, treatment cost and cost of NBS expansion. The benefit of the NBS expansion was conceived as the reduction in the total cost compared to the inaction scenario. The best expansion strategy was understood by the one that temporarily optimizes the advantages of each NBS in relation to the pressures presented by the future scenario. The application of the research problem to the Rio dos Sinos watershed suggested that terraced grasslands would consist of the NBS most suitable for improving water availability, while reforestation would be more suitable for improving water quality. Even so, the results pointed out that the large-scale expansion of NBS over the water systems responsible for supplying big cities would be economically unfeasible when assessing the direct costs and benefits. These results made it evident that the PES and similar programs observed in practice in Brazil operate in areas at least ten times smaller than those necessary to produce noticeable impacts on the water availability of large water systems, which generally occupy hundreds of square kilometers.

Las aguas residuales municipales en zonas rurales representan un peligro de contaminación ambiental y de salud pública. Muchas de las aguas residuales municipales no tienen un tratamiento adecuado para reducir sus niveles de contaminación. A partir de esta problemática se busca una solución que se pueda implementar en zonas rurales sin una gran inversión económica y con bajos requerimientos técnicos para su operación y mantenimiento. En este trabajo se estudia el comportamiento de los humedales artificiales en el tratamiento del agua residual proveniente de la Universidad Autónoma de Occidente (UAO), el comportamiento se analizó en términos de la reducción de materia orgánica y nutrientes (nitrógeno y fosforo) en el agua residual. Este trabajo se llevó a cabo en la estación experimental de humedales artificiales ubicada en la planta de tratamiento de agua residual en la UAO (PTAR-UAO). Se utilizaron dos humedales artificiales de flujo subsuperficial vertical (HV1 y HV2) y un humedal artificial de flujo subsuperficial horizontal (HH), plantados con 2 tipos de macrófitas; lengua de suegra (Sansevieria trifasciata) y heliconia ave del paraíso (Heliconia latispatha). Los humedales fueron operados durante 2 meses y se midieron variables de materia orgánica, nutrientes, sólidos y patógenos. Para seleccionar el humedal con mejor rendimiento se enfocó en la reducción de la DQO, nitritos, nitratos, nitrógeno amoniacal (NA) y fosforo. Los resultados obtenidos en términos de la eficiencia de reducción; de la demanda química de oxígeno (DQO) fueron del 47,8%; 28,2% y 32,1% para el HV1, HV2 y HH respectivamente. Para los nitritos solo se alcanzaron eficiencias de reducción en el HV2 con un valor de 9,2%. Los nitratos presentaron eficiencias de reducción de 48,2%, 9,6% y 53,9% en el HV1, HV2 y HH respectivamente. El nitrógeno amoniacal tuvo eficiencias en el HV1, HV2 y HH de 67,5%, 46,1% y 65,1% respectivamente. En términos de fosforo se obtuvieron eficiencias de reducción superiores al 98% en los 3 humedales. El análisis comparativo realizado a partir del software estadístico Minitab22® permitió establecer que en términos de comportamiento en reducción de DQO, nitritos, nitratos, nitrógeno amoniacal y fosforo los tres humedales presentaron desempeños similares, a diferencia en el contenido de fósforo, donde se encontró que el HV1 presento la eficiencia de reducción más alta de 99,4% con relación a los otros humedales | Municipal wastewater in rural areas represents an environmental and public health pollution hazard. Many of the municipal wastewaters do not have an adequate treatment to reduce their contamination levels. Based on this problem, a solution is sought that can be implemented in rural areas without a large economic investment and with low technical requirements for its operation and maintenance. In this work the behavior of artificial wetlands in the treatment of wastewater from the Universidad Autónoma de Occidente (UAO) is studied, the behavior was analyzed in terms of the reduction of organic matter and nutrients (nitrogen and phosphorus) in the wastewater. This work was carried out in the experimental station of artificial wetlands located in the wastewater treatment plant at the UAO (PTAR-UAO). Two vertical subsurface flow artificial wetlands (HV1 and HV2) and one horizontal subsurface flow artificial wetland (HH) were used, planted with two types of macrophytes; mother-in-law's tongue (Sansevieria trifasciata) and bird-of-paradise heliconia (Heliconia latispatha). The wetlands were operated for 2 months and variables of organic matter, nutrients, solids and pathogens were measured. To select the wetland with the best performance, the focus was on the reduction of COD, nitrites, nitrates, ammonia nitrogen (AN) and phosphorus. The results obtained in terms of chemical oxygen demand (COD) reduction efficiency were 47.8%, 28.2% and 32.1% for HV1, HV2 and HH, respectively. For nitrites, reduction efficiencies were only achieved in HV2 with a value of 9.2%. Nitrates had reduction efficiencies of 48.2%, 9.6% and 53.9% for HV1, HV2 and HH, respectively. Ammonia nitrogen had efficiencies in HV1, HV2 and HH of 67.5%, 46.1% and 65.1%, respectively. In terms of phosphorus, reduction efficiencies of more than 98% were obtained in the 3 wetlands. The comparative analysis carried out using Minitab22® statistical software established that in terms of COD, nitrite, nitrate, ammonia nitrogen and phosphorus reduction performance, the three wetlands presented similar performances, unlike the phosphorus content, where HV1 presented the highest reduction efficiency of 99.4% in relation to the other wetlands | Pasantía de investigación (Ingeniero Ambiental)-- Universidad Autónoma de Occidente, 2024 | Pregrado | Ingeniero(a) Ambiental