scholarly journals Performance assessment of a vertical flow constructed wetland treating unsettled combined sewer overflow

2017 ◽  
Vol 75 (11) ◽  
pp. 2586-2597 ◽  
Author(s):  
T. G. Pálfy ◽  
M. Gerodolle ◽  
R. Gourdon ◽  
D. Meyer ◽  
S. Troesch ◽  
...  
Keyword(s):  
Removal Efficiency ◽  
Constructed Wetland ◽  
Cod Removal ◽  
Vertical Flow ◽  
Combined Sewer Overflow ◽  
Similar Treatment ◽  
Cod Removal Efficiency ◽  
Vertical Flow Constructed Wetland ◽  
Combined Sewer ◽  
Sewer Overflow

The performance of a vertical flow constructed wetland for combined sewer overflow treatment (CSO CW) has been evaluated. The full-scale site has been monitored for 3 years for major pollutants and for two load events for a range of micropollutants (metals, metalloids and polycyclic aromatic hydrocarbons (PAHs)). Performance were predominantly high (97% for total suspended solids (TSS), 80% for chemical oxygen demand (COD), 72% for NH4-N), even if several loads were extremely voluminous, pushing the filter to its limits. Two different filter materials (a 4:1 mixture of sand and zeolite and natural pozzolana) showed similar treatment performance. Furthermore, environmental factors were correlated with COD removal efficiency. The greatest influencers of COD removal efficiency were the inlet dissolved COD concentrations and the duration and potential evapotranspiration during inter-event periods. Furthermore, sludge was analysed for quality and a sludge depth map was created. The map, and calculating the changes in sludge volume, helped to understand solid accumulation dynamics.

Performance of horizontal subsurface flow constructed wetland in the removal of tanninsA paper submitted to the Journal of Environmental Engineering and Science.

2010 ◽  
Vol 37 (3) ◽  
pp. 496-501 ◽  
Author(s):  
K.N. Njau ◽  
M. Renalda
Keyword(s):  
Removal Efficiency ◽  
Constructed Wetland ◽  
Control Cell ◽  
Subsurface Flow ◽  
Oxygen Demand ◽  
Cod Removal ◽  
Outlet Concentration ◽  
Cod Removal Efficiency ◽  
Subsurface Flow Constructed Wetland ◽  
Horizontal Subsurface Flow

A horizontal subsurface flow constructed wetland (HSSFCW) was employed to remove tannins from the effluent of a tannins extracting company. Two HSSFCW cells with hydraulic retention time (HRT) of 9 d and packed with limestone were used. One cell without macrophytes was used as a control, while the second cell was planted with Phragmites mauritianus . Results indicated that HSSFCW was capable of treating tannin wastewater that has been seeded with primary facultative pond sludge. Tannins and chemical oxygen demand (COD) removal efficiency of 95.9% and 90.6% with outlet concentration of 27 mg/L and 86 mg/L, respectively, were obtained in the planted cell; while the tannins and COD removal efficiency of 91.1% and 89.5% with outlet concentration of 57 mg/L and 96 mg/L, respectively, were obtained in the control cell.

Treatment of domestic wastewater by vertical flow constructed wetland planted with umbrella sedge and Vetiver grass

2013 ◽  
Vol 68 (6) ◽  
pp. 1345-1351 ◽  
Author(s):  
Suwasa Kantawanichkul ◽  
Somsiri Sattayapanich ◽  
Frank van Dien
Keyword(s):  
Removal Efficiency ◽  
Constructed Wetland ◽  
Plant Biomass ◽  
Oxygen Demand ◽  
Domestic Wastewater ◽  
Nitrogen Accumulation ◽  
Vertical Flow ◽  
Vetiver Grass ◽  
Vetiveria Zizanioides ◽  
Vertical Flow Constructed Wetland

The aim of this study was to investigate the efficiency of wastewater treatment by vertical flow constructed wetland systems under different hydraulic loading rates (HLR). The comparison of two types of plants, Cyperus alternifolius (Umbrella sedge) and Vetiveria zizanioides (Vetiver grass), was also conducted. In this study, six circular concrete tanks (diameter 0.8 m) were filled with fine sand and gravel to the depth of 1.23 m. Three tanks were planted with Umbrella sedge and the other three tanks were planted with Vetiver grass. Settled domestic wastewater from Chiang Mai University (chemical oxygen demand (COD), NH4+-N and suspended solids (SS) of 127.1, 27.4 and 29.5 mg/L on average, respectively) was intermittently applied for 45 min and rested for 3 h 15 min. The HLR of each tank was controlled at 20, 29 and 40 cm/d. It was found that the removal efficiency of the Umbrella sedge systems was higher than the Vetiver grass systems for every parameter, and the lowest HLR provided the maximum treatment efficiency. The removal efficiency of COD and nitrogen in terms of total Kjeldahl nitrogen (TKN) was 76 and 65% at 20 cm/d HLR for Umbrella sedge compared to only 67 and 56% for Vetiver grass. Nitrogen accumulation in plant biomass was also higher in Umbrella sedge than in Vetiver grass in every HLR. Umbrella sedge was thus proved to be a suitable constructed wetland plant in tropical climates.

Reduction of micropollutants and bacteria in a constructed wetland for combined sewer overflow treatment after 7 and 10 years of operation

2019 ◽  
Vol 651 ◽  
pp. 917-927 ◽  
Author(s):  
Katharina Tondera ◽  
Jan P. Ruppelt ◽  
Johannes Pinnekamp ◽  
Thomas Kistemann ◽  
Christiane Schreiber
Keyword(s):  
Constructed Wetland ◽  
Combined Sewer Overflow ◽  
Combined Sewer ◽  
Sewer Overflow

Experience with Vortex Separators for Combined Sewer Overflow Control

1993 ◽  
Vol 27 (5-6) ◽  
pp. 93-104 ◽  
Author(s):  
H. Brombach ◽  
C. Xanthopoulos ◽  
H. H. Hahn ◽  
W. C. Pisano
Keyword(s):  
Separation Efficiency ◽  
Operational Reliability ◽  
Second Phase ◽  
Combined Sewer Overflow ◽  
Specific Storage ◽  
Impervious Area ◽  
Evaluation Phase ◽  
Combined Sewer ◽  
Sewer Overflow ◽  
Overflow Control

In 1987 the first vortex solids separator facility in Germany was installed for combined sewer overflow (CSO) control. The separation efficiency was optimized in the hydraulic laboratory using scaled down models with artificial tracers to simulate typical sewage particulates. The station has two parallel operating vortex separators and serves a connected and impervious area of about 11 hectares (ha) and 1,500 people. The specific storage volume of the station is 7.2 m3 per ha. Two evaluation programs were conducted. The first evaluation phase noted the operational reliability, hydraulic loads, overflow frequencies and water mass balances. The second phase monitored separation efficiencies. The evaluation showed that vortex solids separators are now ready for use in CSO control.

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