|
|
|
African Journal of Agricultural Research Vol. 1 (2), pp.
027-037, September 2006
© 2006 Academic Journals
Full Length Research Paper
Effects of hydraulic retention time and
media of constructed wetland for treatment of domestic wastewater
Suntud Sirianuntapiboon1*,
Manoch Kongchum2 and Worawut Jitmaikasem1
1Department
of Environmental Technology, School of Energy and Materials, King
Mongkut’s University of Technology Thonburi (KMUTT), Bangkok 10140,
Thailand.
2Department
of Agronomyand Environmental Management, Louisiana State University, Botan
Rouge, LA 70803, USA.
Corresponding author.E-mail:
suntud.sir@kmutt.ac.th.
Abbreviations: BOD5, Biochemical Oxygen demand; COD, chemical oxygen demand;
HRT, hydraulic retention time; NH4+, ammonium; NO2-, nitrite; NO3-, nitrate nitrogen;
SRT, solids retention time; SS, suspended solids; TKN, total kjeldahl nitrogen;
TP, total phosphate; and UFCW, up-flow constructed wetland.
Accepted
26 August, 2006 |
|
|
|
A
greenhouse experiment was conducted to investigate the effect of varying
soil-to-sand ratios of constructed wetland on wastewater treating
efficiency. Wetland beds were prepared with locally available plants,
specifically cattail (Typha sp.). Treatment efficiency was
evaluated for parameters such as BOD5, COD, SS, TKN and TP. The
results indicated that the nutrient reduction corresponds to a longer
retention time in wetland beds. Under the longest hydraulic retention time
(HRT) of 3 days, the system with media containing a soil-to-sand ratio of
75:25 illustrated the highest removal efficiencies of BOD5,
COD, SS, TKN and TP by 92±5, 91±%, 76±9, 90±3 and
95±3%, respectively. The infiltration rate was also decreased after
operation, particularly in the treatment with lower sand content. However,
the highest growth rate of cattail was found under the shortest HRT (0.75
day) condition.
Key
words:
Hydraulic retention time (HRT), Media, Typha sp., constructed
wetland. |
|
.gif){kind=small}
