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.

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.

scholarly journals TREATMENT OF SEPTIC TANK SLUDGE IN A VERTICAL FLOW CONSTRUCTED WETLAND SYSTEM

2017 ◽  
Vol 37 (4) ◽  
pp. 811-819 ◽  
Author(s):  
Cynthia F. Andrade ◽  
Marcos Von Sperling ◽  
Elias S. Manjate
Keyword(s):  
Constructed Wetland ◽  
Septic Tank ◽  
Vertical Flow ◽  
Vertical Flow Constructed Wetland ◽  
Wetland System

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.

Effects of clogging on hydraulic behavior in a vertical-flow constructed wetland system: A modelling approach

2017 ◽  
Vol 109 ◽  
pp. 41-47 ◽  
Author(s):  
Mengyao Yang ◽  
Mingzhi Lu ◽  
Hongfeng Bian ◽  
Lianxi Sheng ◽  
Chunguang He
Keyword(s):  
Constructed Wetland ◽  
Vertical Flow ◽  
Hydraulic Behavior ◽  
System A ◽  
Vertical Flow Constructed Wetland ◽  
Wetland System ◽  
Modelling Approach
Sign in / Sign up

Export Citation Format

Share Document