A carregar...
Projeto de investigação
Sem título
Financiador
Autores
Publicações
Vertical flow constructed wetland as a green solution for low biodegradable and high nitrogen wastewater: A case study of explosives industry
Publication . Madeira, Luís Miguel; Carvalho, Fatima; Teixeira, Margarida Ribau; Ribeiro, Carlos; Almeida, Adelaide
The removal of nitrogen compounds from a pretreated explosives wastewater in vertical flow constructed wetland planted with Vetiveria zizanioides (0.24 m(2) x 0.70 m), filled with light expanded clay aggregates (Leca (R) NR 10/20), was studied. Experiments under constant hydraulic load, 50 +/- 4 Lm(-2) d(-1) and 83 +/- 5 L m(-2) d(-1) without and with flooding level (25%), respectively, were made at different ammonium (3-48 mg NH4+-N L-1), nitrate (56-160 mg NO3--N L-1) and nitrite (0.3-1.1 mg NO2--N L-1) concentrations. Results indicate that without flooding level (unsaturated) the removal efficiencies obtained were 30 +/- 9, 7 +/- 1 and 96 +/- 2%, respectively to NH4+-N, NO3--N and NO2--N. When using flooding level and an external carbon source (C/N ratio from 1.3 +/- 0.19 to 2.5 +/- 0.20), the organic matter (COD) removal efficiencies were above 90%, 75% for NH4+-N and 55% to NO3--N. Increasing the C/N ratio from 2.9 +/- 0.21 to 4 +/- 0.22 did not contributed to upgrade the efficiencies of COD, NH4+-N and NO3--N removal. The denitrification process was occurred in aerobic conditions and nitrite production have ben occurred, probably due to the presence of aerobic conditions that inhibited partially denitrification. (C) 2021 Elsevier Ltd. All rights reserved.
Unidades organizacionais
Descrição
Palavras-chave
Contribuidores
Financiadores
Entidade financiadora
Fundação para a Ciência e a Tecnologia
Programa de financiamento
OE
Número da atribuição
71415