Influence of application of manganese ore in constructed wetlands on the mechanisms and improvement of nitrogen and phosphorus removal.
Ecotoxicol Environ Saf
; 170: 446-452, 2019 Apr 15.
Article
em En
| MEDLINE
| ID: mdl-30553922
ABSTRACT
Vertical up-flow constructed wetlands (CWs) with manganese ore (Mn ore) as media (M-CWs) were developed to treat simulated polluted river water. The results showed that the average removal efficiencies for NH4-N, NO3-N, TN and TP were 91.74%, 83.29%, 87.47% and 65.12% in M-CWs, respectively, which were only 79.12%, 72.90%, 75.85% and 43.23% in the CWs without Mn ore (C-CWs). Nutrient mass balance showed that nitrogen (N) removal was improved by enhanced microbial processes, media storage and plant uptake in M-CWs. Moreover, almost 50% of phosphorus (P) was retained by media storage because of the adsorption processes on Mn ore. It was found that addition of Mn ore enhanced denitrification as the relative abundance of denitrifying bacteria increased. The produced Mn(II) and more abundant Gammaproteobacteria confirmed alternative N removal pathways including anoxic nitrification coupled to Mn ore reduction and denitrification using Mn(II) as electron donor. Mn(II) concentration in the effluent of M-CWs was below the drinking water limit of 0.1â¯mg/L, which makes them environmentally-friendly.
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Texto completo:
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Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Fósforo
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Poluentes Químicos da Água
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Áreas Alagadas
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Manganês
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Nitrogênio
Idioma:
En
Ano de publicação:
2019
Tipo de documento:
Article