Avaliação do desempenho das zonas húmidas construídas: estudo de caso Barroca d'Alva

• Author(s): Botequilha, José Ricardo Martins
• Date: 2013
• Persistent ID: http://hdl.handle.net/10400.5/6700
• Origin: Repositório da UTL
• Subject(s): constructed wetlands; seasonal variations; domestic wastewater treatment; concentration peaks
• Document Type: Master thesis
• Language: Portuguese
• Advisor(s): Oliveira, Maria Margarida da Costa Ferreira Correia de; Duarte, Elizabeth Fernandes de Almeida; Caldas, Cristina Maria Gameiro
• Contributor(s): Repositório da Universidade de Lisboa

Description

Mestrado em Engenharia do Ambiente - Instituto Superior de Agronomia

Constructed Wetlands (CW) are suitable for rural areas with high environmental and cost-benefits compared with conventional treatment systems for wastewater due to its high construction cost and need for continuously technical supervision. This alternative technology consists on man-made system that reproduces the processes that occur during the water purification in natural wetlands. The wastewater flows through the porous medium under the surface of the beds which are planted with macrophytes ensuring the removal of pollutants. The present work aimed to study the effect of seasonal variation on the removal of pollutants during spring and summer in CW of Barroca D’Alva. This work also studies the buffering capacity of the wetland after a series of increment of organic loading rate at Barroca D’Alva. In spring the removal efficiencies obtained were 40% for total suspended solids (TSS), 97% for biochemical oxygen demand in 5 days (BOD5), 60% for soluble phosphorus, more than 90% for nitrogen and 99% for pathogen. The summer season showed better results (66.6% for SST, 98% for BOD5, 80% for soluble phosphorus, more than 90% for nitrogen and 99% for pathogen). Despite the over sizing of CW it showed high efficiency in removing pollutants. The concentrations of pollutants in the discharge site were below the Portuguese standards.