Wetlands verticais: desempenho de diferentes meios filtrantes e níveis de saturação no tratamento de efluentes em um residencial universitário

• Ano de defesa: 2025
• Autor(a) principal: Rodrigues, Gabriela Anzanello
• Tipo de documento: Dissertação
• Tipo de acesso: Acesso aberto
• Idioma: por
• Instituição de defesa: Universidade Federal de Santa Maria; Brasil; Ciências Ambientais; UFSM; Programa de Pós-Graduação em Ciência e Tecnologia Ambiental; UFSM Frederico Westphalen
• Palavras-chave em Português: Wetland vertical; Saturação parcial; Tratamento descentralizado; Influência do clima; Eficiência de remoção; Vertical wetland; Partial saturation; Decentralized treatment; Climate Influence; Removal efficiency; CNPQ::OUTROS::CIENCIAS
• Link de acesso: http://repositorio.ufsm.br/handle/1/34540

The universalization of sanitation represents an urgent demand for wastewater treatment systems that are resilient, efficient, and aligned with the principles of the circular economy. Vertical Flow Constructed Wetlands (VFCWs) stand out as an alternative, including for isolated and/or rural communities. This technology has been improved over time, incorporating strategies such as partial saturation, which aims to enhance pollutant removal performance. This study evaluated the performance of a Partially Saturated Vertical Flow Constructed Wetlands (PS-VFCW) system installed to serve a university residence. The system consists of four PS-VFCW units (23.8 m² each) planted with Canna x generalis, two filled with sand and two with gravel, named WS-15, WS-25, WG-15, and WG-25, according to their saturation level (0.15 m and 0.25 m, respectively) and filling material (S for sand and G for gravel). The sand units operate intermittently, while the gravel units operate without resting periods. Physicochemical parameters were monitored, as well as the influence of climatic elements on the removal efficiency of nitrogen, carbonaceous organic matter, and other compounds. The results indicate that the sand-filled units showed better performance, especially WS-25, which achieved removal efficiencies of 64% for NH4 + - N and 77% for COD. Among the gravel units, WG-25, with a higher saturation level, also demonstrated superior performance, with removal rates of 40% for NH4 + -N and 66% for COD. The results refer to the first nine months of operation, during which the system faced adverse conditions for biofilm and plant development, such as low organic load and drastic flow fluctuations. Although the gravel units showed lower efficiencies, WG-25 stands out for operational advantages compared to the sand units, such as reduced required area (as it operates continuously), longer lifespan (due to lower clogging tendency), reduced maintenance needs, and lower installation and operational costs. The climatic elements that most influenced system performance were precipitation and solar radiation. The results suggest that prolonged periods of heavy rainfall tend to hinder treatment, while higher temperatures and greater solar radiation exposure enhance pollutant removal. However, the observed correlations can indicate that the measured removal rates may be influenced by pollutant dilution or concentration in the effluent, potentially overestimating or underestimating the actual efficiency of the units. PS-VFCWs demonstrate potential as an efficient and sustainable solution for decentralized domestic wastewater treatment, contributing to the expansion of sanitation in rural and remote areas, especially the gravel-filled units with a higher saturation level.