scholarly journals Performance monitoring of a vertical flow constructed wetland treating municipal wastewater

2013 ◽  
Vol 9 (3) ◽  
pp. 277-285
Keyword(s):  
Water Quality ◽  
Constructed Wetland ◽  
Performance Monitoring ◽  
Municipal Wastewater ◽  
Monitoring Program ◽  
Vertical Flow ◽  
Total Coliforms ◽  
Vertical Flow Constructed Wetland ◽  
Reliable Performance ◽  
Removal Efficiencies

A two-year monitoring program was undertaken in a vertical flow constructed wetland treating wastewater from Gomati, a village in Chalkidiki, North Greece. This constructed wetland operates since 2003. The monitoring campaigns were organized every 15 days. Water quality samples were collected at the inlet, at intermediate points (i.e., at the end of each treatment stage) and at the outlet of the system. Measured mean removal efficiencies were as follows: 92.3% for BOD, 91.7% for COD, 80.3% for TKN, 87.5% for ΝΗ4 +, 61.3% for TP, 45.7% for ortho-phosphates, 93.2% for TSS and 99.9% for total coliforms, which suggests a satisfactory and reliable performance of such systems in Greece. The paper presents facility description, study details and monitoring results.

Treatment of olive mill and municipal wastewater mixture by pilot scale vertical flow constructed wetland

2020 ◽  
Vol 198 ◽  
pp. 126-139
Author(s):  
Ayoub El Ghadraoui ◽  
Naaila Ouazzani ◽  
Abdelaali Ahmali ◽  
Tawfiq El Hakim El Mansour ◽  
Faissal Aziz ◽  
...  
Keyword(s):  
Constructed Wetland ◽  
Municipal Wastewater ◽  
Pilot Scale ◽  
Vertical Flow ◽  
Vertical Flow Constructed Wetland ◽  
Olive Mill

Vertical flow constructed wetland for textile effluent treatment

2007 ◽  
Vol 55 (7) ◽  
pp. 127-134 ◽  
Author(s):  
L.C. Davies ◽  
A. Vacas ◽  
J.M. Novais ◽  
F.G. Freire ◽  
S. Martins-Dias
Keyword(s):  
Constructed Wetland ◽  
Effluent Treatment ◽  
Textile Effluent ◽  
Model Parameters ◽  
Vertical Flow ◽  
Mass Load ◽  
Vertical Flow Constructed Wetland ◽  
Pulse Feed ◽  
In Series ◽  
Removal Efficiencies

A pulse feed vertical flow constructed wetland (VFCW) proved to be efficient in the treatment of a textile effluent being able to buffer, dilute and treat an Acid Orange (AO7) accidental discharge. The influence of the flooding level (FL) and pulse feed (PF) duration on the removal efficiencies of a VFCW was examined. Average AO7 removal efficiencies of 70% were achieved for an AO7 Inlet concentration of 700 mg l−1 applied during 15 min cycle−1 (every three hours) at a hydraulic load of 13 l m−2 cycle−1 and an FL of 21%. The VFCW was modelled by analogy with a combination of ideal reactors. The simplest combination that best reproduced the experimental results was an association of 2 reactors in series plus 1 reactor accounting the dead volumes. The model parameters helped to understand the hydrological and kinetic processes occurring in VFCW. Through the model simulation it was shown that 3 VFCW in series were enough to efficiently treat an organic mass load of 76 gAO7 m−2 day−1 in 9 hours and fulfil the discharge legislation. In this work it was possible to establish that the overall degradation kinetics was of first order.

Removal of indicator bacteria from municipal wastewater in an experimental two-stage vertical flow constructed wetland system

2003 ◽  
Vol 48 (5) ◽  
pp. 35-41 ◽  
Author(s):  
C.A. Arias ◽  
A. Cabello ◽  
H. Brix ◽  
N.-H. Johansen
Keyword(s):  
Constructed Wetland ◽  
Rate Constants ◽  
Indicator Bacteria ◽  
Vertical Flow ◽  
Faecal Coliforms ◽  
Total Coliforms ◽  
Sedimentation Tank ◽  
Vertical Flow Constructed Wetland ◽  
Wetland System ◽  
Faecal Streptococci

The removal of sanitary indicator bacteria (total coliforms, faecal coliforms, and faecal streptococci) was studied in an experimental constructed wetland system consisting of (1) a 2-m3 three-chamber sedimentation tank, (2) a 5 m2 vertical flow constructed wetland, (3) a filter-unit with calcite aimed at removing phosphorus, and (4) a 10 m2 vertical flow constructed wetland. The indicator bacteria were enumerated before and after each unit of the wetland system during four monitoring episodes with different loading conditions. At a hydraulic loading rate of 520-1,370 mm/d, the first-stage vertical flow beds removed about 1.5 log-units of total coliforms, 1.7 log-units of faecal coliforms and 0.8 log-units of faecal streptococci. In the second stage bed receiving lower loadings both in term of concentration and quantity (260-690 mm/day), the eliminations were lower. It was not possible in the present study to identify any seasonal effects, but no measurements were done during summer. Recycling of treated effluent back to the sedimentation tank did not affect elimination. Area-based rate constants for the vertical flow wetland receiving effluent from the sedimentation tank averaged 3.2 m/d for total coliforms, 3.3 m/d for faecal coliforms and 2.1 m/d for faecal streptococci. The rate constants depended on loading rates. It is suggested that filtration is a major removal mechanism for bacterial indicator organisms in vertical flow constructed wetland systems.

Phosphorus removal from municipal wastewater in an experimental two-stage vertical flow constructed wetland system equipped with a calcite filter

2003 ◽  
Vol 48 (5) ◽  
pp. 51-58 ◽  
Author(s):  
C.A. Arias ◽  
H. Brix ◽  
N.-H. Johansen
Keyword(s):  
Constructed Wetland ◽  
Phosphorus Removal ◽  
Municipal Wastewater ◽  
Unsaturated Flow ◽  
Loading Rate ◽  
Real Life ◽  
Vertical Flow ◽  
First Order ◽  
Sedimentation Tank ◽  
Vertical Flow Constructed Wetland

Laboratory studies have indicated that calcite may be used in separate, exchangeable filter units in constructed wetland systems to remove phosphorus. Based on these studies we built a full-scale experimental constructed wetland with a calcite-based filter unit to study its performance, under real-life conditions. The system consists of a 2-m3 sedimentation tank and two vertical flow constructed wetlands. The system has three 0.09 m3 calcite filter-units to study phosphorus removal. The hydraulic loading rate varied between 1.7 and 6.2 m3/d. The residence time in filters ranged from 28 to 99 minutes. Overall the system removed 62 ± 18% of phosphorus. The removal in the calcite filter was initially good, but after three months all P-filters were saturated. The calcite increased pH by approximately half a unit and released calcium. A total of about 2.2 kg P/m3 calcite was removed by the filter. The first-stage bed receiving effluent from the sedimentation tank consistently removed phosphorus, whereas the second bed sometimes released phosphorus. The first order area-based removal rate constant for total-P in the vertical bed averaged 0.24 ± 0.20 m/d and was highly dependent on the loading rate. This shows that first order removal kinetics do not satisfactorily describe removal of phosphorus in vertical flow constructed wetland systems with unsaturated flow.

First stage of the French vertical flow constructed wetland system: experiments with the reduction of surface area and number of units

2014 ◽  
Vol 5 (1) ◽  
pp. 50-55 ◽  
Author(s):  
E. S. Manjate ◽  
L. C. O. Lana ◽  
D. C. Moraes ◽  
G. R. Vasconcellos ◽  
G. R. M. Maciel ◽  
...  
Keyword(s):  
Constructed Wetland ◽  
Oxygen Demand ◽  
Feeding Strategies ◽  
Attractive Alternative ◽  
Second Phase ◽  
Vertical Flow ◽  
Full System ◽  
Mean Values ◽  
Vertical Flow Constructed Wetland ◽  
Removal Efficiencies

Small vertical-flow constructed wetland units comprising the first stage of the French system were studied in Brazil for the treatment of raw sewage. Planted and unplanted units and different feeding strategies were tested. In the first phase, hourly batches of a daily flow of 13 m3 d−1 were applied over three alternating units, resulting in an average hydraulic loading rate (HLR) on the full system of 0.15 m3 m−2 d−1. A second phase, aimed at reducing land requirements, kept the same daily flow and batch frequency, but used two alternating units, resulting in a HLR on the full system of 0.22 m3 m−2 d−1. Removal efficiencies were very good when the system operated with three units, with mean values of 82% for biochemical oxygen demand (BOD), 81% for chemical oxygen demand (COD), 85% for total suspended solids (TSS) and 59% for NH4+-N. With two units, the equivalent values were 74% for BOD, 59% for COD, 67% for TSS and 51% for NH4+-N. There were significant differences in the median removal efficiencies of COD and TSS. No significant differences were found between planted and unplanted units for most constituents. In both phases, the overall good performance and the simplicity of the system make this treatment process a very attractive alternative for developing countries.

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