Effect of Submerged and Floating Plants on Dissolved Oxygen Dynamics and Nitrogen Removal in Constructed Wetlands
<p>Dissolved oxygen (DO) concentration affects the treatment processes in constructed wetlands. This study examined the dissolved oxygen dynamics and total nitrogen removal in constructed wetlands with submerged and floating plants. Four constructed wetland units each with the surface area of...
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| Format: | Article |
| Language: | English |
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Postgraduate Institute of Agriculture, University of Peradeniya
2011-08-01
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| Series: | Tropical Agricultural Research |
| Subjects: | |
| Online Access: | https://tar.sljol.info/articles/3311 |
| _version_ | 1818981431065444352 |
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| author | BGN Sewwandi SK Weragoda MIM Mowjood N Tanaka S Sasikala |
| author_facet | BGN Sewwandi SK Weragoda MIM Mowjood N Tanaka S Sasikala |
| author_sort | BGN Sewwandi |
| collection | DOAJ |
| description | <p>Dissolved oxygen (DO) concentration affects the treatment processes in constructed wetlands. This study examined the dissolved oxygen dynamics and total nitrogen removal in constructed wetlands with submerged and floating plants. Four constructed wetland units each with the surface area of 3 x 1 m<sup>2</sup> were constructed at University of Peradeniya. Two of those with the depths of 0.3 m (A) and 0.6 m (B) were planted separately with <em>Hydrilla verticillata</em> (submerged) and <em>Lemna minor</em> (floating), respectively. Other two (C and D) were constructed with two sections of 0.3 and 0.6 m depths and planted with <em>H. verticillata</em> and <em>L. minor</em>, respectively in each section. Secondary effluent from student hostel was fed with hydraulic retention time of 6 days. DO was measured at different depths of water, 0.0, 0.1, 0.2, 0.4 and 0.5 m from the water surface and along the longitudinal axis of the wetland at 6 hours interval. The total nitrogen was measured for water samples at inlet and outlets. The average dissolved oxygen concentrations of A and B were 17.7 and 0.4 mg L<sup>-1</sup> respectively. Oxic condition was maintained in the submerged plant units. Anoxic condition resulted throughout the day in floating plant system. DO varied significantly with depths in oxic condition. DO dynamics in these wetlands can be explained by photosynthesis, respiration, deaeration and reaeration processes. The highest total nitrogen removal was achieved in unit D where combined anoxic and oxic conditions were maintained together <em>H. verticillata</em> and <em>L. minor</em> could effectively be used to maintain required dissolved oxygen in constructed wetlands for nitrate removal.</p><p>DOI: http://dx.doi.org/10.4038/tar.v21i4.3311</p><p><em>TAR </em>2010; 21(3): 353-360</p> |
| first_indexed | 2024-12-20T17:31:12Z |
| format | Article |
| id | doaj.art-0fdc0ee690e9499681737ba87df0ee0f |
| institution | Directory Open Access Journal |
| issn | 1016-1422 |
| language | English |
| last_indexed | 2024-12-20T17:31:12Z |
| publishDate | 2011-08-01 |
| publisher | Postgraduate Institute of Agriculture, University of Peradeniya |
| record_format | Article |
| series | Tropical Agricultural Research |
| spelling | doaj.art-0fdc0ee690e9499681737ba87df0ee0f2022-12-21T19:31:23ZengPostgraduate Institute of Agriculture, University of PeradeniyaTropical Agricultural Research1016-14222011-08-0121435336010.4038/tar.v21i4.33112769Effect of Submerged and Floating Plants on Dissolved Oxygen Dynamics and Nitrogen Removal in Constructed WetlandsBGN Sewwandi0SK Weragoda1MIM Mowjood2N Tanaka3S Sasikala4Postgraduate Institute of Agriculture, University of Peradeniya, PeradeniyaGraduate School of Science and Engineering, Saitama UniversityDepartment of Agricultural Engineering, Faculty of Agriculture, University of PeradeniyaGraduate School of Science and Engineering, Saitama UniversityDepartment of Agricultural Engineering, Faculty of Agriculture, University of Peradeniya<p>Dissolved oxygen (DO) concentration affects the treatment processes in constructed wetlands. This study examined the dissolved oxygen dynamics and total nitrogen removal in constructed wetlands with submerged and floating plants. Four constructed wetland units each with the surface area of 3 x 1 m<sup>2</sup> were constructed at University of Peradeniya. Two of those with the depths of 0.3 m (A) and 0.6 m (B) were planted separately with <em>Hydrilla verticillata</em> (submerged) and <em>Lemna minor</em> (floating), respectively. Other two (C and D) were constructed with two sections of 0.3 and 0.6 m depths and planted with <em>H. verticillata</em> and <em>L. minor</em>, respectively in each section. Secondary effluent from student hostel was fed with hydraulic retention time of 6 days. DO was measured at different depths of water, 0.0, 0.1, 0.2, 0.4 and 0.5 m from the water surface and along the longitudinal axis of the wetland at 6 hours interval. The total nitrogen was measured for water samples at inlet and outlets. The average dissolved oxygen concentrations of A and B were 17.7 and 0.4 mg L<sup>-1</sup> respectively. Oxic condition was maintained in the submerged plant units. Anoxic condition resulted throughout the day in floating plant system. DO varied significantly with depths in oxic condition. DO dynamics in these wetlands can be explained by photosynthesis, respiration, deaeration and reaeration processes. The highest total nitrogen removal was achieved in unit D where combined anoxic and oxic conditions were maintained together <em>H. verticillata</em> and <em>L. minor</em> could effectively be used to maintain required dissolved oxygen in constructed wetlands for nitrate removal.</p><p>DOI: http://dx.doi.org/10.4038/tar.v21i4.3311</p><p><em>TAR </em>2010; 21(3): 353-360</p>https://tar.sljol.info/articles/3311submerged and floating plantsdissolved oxygen dynamicsnitrogen removalconstructed wetlands |
| spellingShingle | BGN Sewwandi SK Weragoda MIM Mowjood N Tanaka S Sasikala Effect of Submerged and Floating Plants on Dissolved Oxygen Dynamics and Nitrogen Removal in Constructed Wetlands Tropical Agricultural Research submerged and floating plants dissolved oxygen dynamics nitrogen removal constructed wetlands |
| title | Effect of Submerged and Floating Plants on Dissolved Oxygen Dynamics and Nitrogen Removal in Constructed Wetlands |
| title_full | Effect of Submerged and Floating Plants on Dissolved Oxygen Dynamics and Nitrogen Removal in Constructed Wetlands |
| title_fullStr | Effect of Submerged and Floating Plants on Dissolved Oxygen Dynamics and Nitrogen Removal in Constructed Wetlands |
| title_full_unstemmed | Effect of Submerged and Floating Plants on Dissolved Oxygen Dynamics and Nitrogen Removal in Constructed Wetlands |
| title_short | Effect of Submerged and Floating Plants on Dissolved Oxygen Dynamics and Nitrogen Removal in Constructed Wetlands |
| title_sort | effect of submerged and floating plants on dissolved oxygen dynamics and nitrogen removal in constructed wetlands |
| topic | submerged and floating plants dissolved oxygen dynamics nitrogen removal constructed wetlands |
| url | https://tar.sljol.info/articles/3311 |
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