River water quality improvement by natural and constructed wetland systems in the tropical semi-arid region of northeastern Brazil.
Water Sci Technol
; 44(11-12): 599-605, 2001.
Article
em En
| MEDLINE
| ID: mdl-11804156
ABSTRACT
The efficiencies of a natural Typha spp wetland (Wn) formed on a river bed and its effluent treatment in a constructed wetland (Wc, subsurface horizontal flow) were investigated in northeastern Brazil (Paraiba State). The Wc system (12 tanks with stone gravel, 4.13 m2, 0.22 m3, 20 Typha spp rhizomes, m(-2) each, with 38, 29, and 19 mm x d(-1) hydraulic loadings, and 5, 7, and 10 days HRT) was fed daily with effluent from a Wn. Wn removal presented the highest values after Typha spp were cut during the 5th week. Removal values were (1st and 2nd periods or before and after cutting) 75% and 81% BOD5; 10-53% total phosphorus; 13%-55% ammonia; 89%-91% FC; 90-96% coliphages and bacteriophages. Wc removals increased with time with best results on 10 d HRT. Removals were also higher in the 2nd period 74%-78% BOD5; 58%-82% ammonia; 90% FC; 94-98% FS; and 92%-96% coliphages and bacteriophages. Despite the high remaining values of FC (1.4 x 10(4) CFU/100 ml) and FX (4 x 10(3) CFU/100 ml), the removals were satisfactory and HRT dependent, suggesting a gradual optimization of the system with time. The Wc exhibited good efficiency for improving water quality from polluted river.
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Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Microbiologia da Água
/
Poluição da Água
/
Ecossistema
País/Região como assunto:
America do sul
/
Brasil
Idioma:
En
Revista:
Water Sci Technol
Assunto da revista:
SAUDE AMBIENTAL
/
TOXICOLOGIA
Ano de publicação:
2001
Tipo de documento:
Article
País de afiliação:
Brasil