Horizontal sub-surface flow constructed wetland with pulsing water level

2003 ◽  
Vol 48 (5) ◽  
pp. 143-148 ◽  
Author(s):  
J. Vymazal ◽  
M. Masa
Keyword(s):  
Water Level ◽  
Constructed Wetland ◽  
Municipal Wastewater ◽  
Water Discharge ◽  
Experimental Period ◽  
Surface Flow ◽  
Treatment Efficiency ◽  
Outflow Velocity ◽  
In Series ◽  
Positive Effect

A constructed wetland with horizontal sub-surface flow at Dolni Mesto (Czech Republic) was put into operation in 1999 and treats municipal wastewater from 522 PE. The total area of vegetated beds of 2,646 m2 is divided into two parallel sections of equal size, each with two beds in series. Between two periods of water discharge there is no outflow from the bed. During the period of September 1999-September 2000 one bed was operated with a pulsing water level while the other one was not pulsing, i.e., was operated as regular sub-surface flow in order to evaluate the effect of pulsing on treatment efficiency, especially on removal of NH4-N. Between September 1999 and February 2000 the pulse was 8 cm, for the rest of the experimental period the pulse was 15 cm. The results indicate a positive effect of pulsing on removal of BOD5 (annual average of 53%), COD (30%) and NH4-N (27%) as compared to non-pulsing beds. For SS, a decrease in removal effect by 30% was observed. This is probably due to the higher outflow velocity of discharged water from pulsing beds which can flush out settled particles. The results also indicate that a pulsing level of 15 cm was more efficient than 8 cm.

Nutrient Reduction in an In-Series Constructed Wetland System Treating Landfill Leachate

1994 ◽  
Vol 29 (4) ◽  
pp. 267-272 ◽  
Author(s):  
Craig D. Martin ◽  
Gerald A. Moshiri
Keyword(s):  
Constructed Wetland ◽  
Surface Flow ◽  
Pollutant Removal ◽  
Nutrient Reduction ◽  
Loop Design ◽  
In Series ◽  
Waste Facility ◽  
Maximum Water ◽  
Vascular Aquatic Plants

The effectiveness of an in-series surface flow constructed wetland designed to treat landfill leacbate was determined by conducting pollutant removal efficiency studies over a 4 month period. The first step in the study involved the characterization of the leacbate generated within the landfill. At the same time, ten in-series parallel wetlands with a 10:1 length to aspect ratio were constructed, with each cell designed for a maximum water depth of 0.5m. Cells were planted with a variety of vascular aquatic plants including Sagittaria spp., Pontedaria sp., Scirpus spp., Phragmities sp., Typha sp., Juncus spp., and Zizaniopsis sp.. This system is a component of a solid waste facility of a closed-loop design incorporating recycling, composting and constructed wetlands to treat leacbate mixed with septage on site. The system is characterized by a varying hydraulic loading rate and retention time.

Removal of persistent organic pollutants from landfill leachates treated in three constructed wetland systems

2013 ◽  
Vol 68 (5) ◽  
pp. 1164-1172 ◽  
Author(s):  
Ewa Wojciechowska
Keyword(s):  
Organic Pollutants ◽  
Persistent Organic Pollutants ◽  
Constructed Wetland ◽  
Subsequent Treatment ◽  
Surface Flow ◽  
Horizontal Flow ◽  
Major Mechanism ◽  
Flow Systems ◽  
Polycyclic Aromatic ◽  
In Series

The objective of the study was assessment of occurrence and removal of two groups of persistent organic pollutants: polycyclic aromatic hydrocarbons (PAHs) and polychlorinated biphenyls (PCBs) in landfill leachate (LL) treated in three constructed wetland systems (CWs) of different construction and flow regime. Two subsurface flow systems (SSF) were analyzed: one with horizontal flow and the second one consisting of two vertical flow beds followed by a horizontal flow bed. The third CW was a surface flow (SF) system, consisting of 10 ponds connected in series. The concentrations of 12 PAHs and 7 PCBs were measured in the samples of LL after subsequent treatment stages and in the sediment samples from the SF system as well as in the substrate samples from the SSF flow systems. It was confirmed that the major mechanism of PCB and PAH removal in CW systems was adsorption to the bottom sediments (in the SF system) or substrate of the beds (in the SSF systems) as well as adsorption to suspended solids, followed by sedimentation. The compounds characterized by higher octanol/water partition coefficient were more effectively retained in the sediments. Also removal of these substances occurred in the earlier stages of treatment.

Wastewater treatment performance efficiency of constructed wetlands in African countries: a review

2014 ◽  
Vol 71 (1) ◽  
pp. 1-8 ◽  
Author(s):  
Andualem Mekonnen ◽  
Seyoum Leta ◽  
Karoli Nicholas Njau
Keyword(s):  
Wastewater Treatment ◽  
Constructed Wetland ◽  
Oxygen Demand ◽  
Surface Flow ◽  
Operational Parameters ◽  
Treatment Efficiency ◽  
African Countries ◽  
Wetland Type ◽  
Treatment Performance ◽  
Nutrient Removal Efficiency

In Africa, different studies have been conducted at different scales to evaluate wastewater treatment efficiency of constructed wetland. This paper aims to review the treatment performance efficiency of constructed wetland used in African countries. In the reviewed papers, the operational parameters, size and type of wetland used and the treatment efficiency are assessed. The results are organized and presented in six tables based on the type of wetland and wastewater used in the study. The results of the review papers indicated that most of the studies were conducted in Tanzania, Egypt and Kenya. In Kenya and Tanzania, different full-scale wetlands are widely used in treating wastewater. Among wetland type, horizontal subsurface flow wetlands were widely studied followed by surface flow and hybrid wetlands. Most of the reported hybrid wetlands were in Kenya. The results of the review papers indicated that wetlands are efficient in removing organic matter (biochemical oxygen demand and chemical oxygen demand) and suspended solids. On the other hand, nutrient removal efficiency appeared to be low.

Gravel Media Filtration as a Constructed Wetland Component for the Reduction of Suspended Solids from Maturation Pond Effluent

1994 ◽  
Vol 29 (4) ◽  
pp. 55-66 ◽  
Author(s):  
D. P. Sapkota ◽  
H. J. Bavor
Keyword(s):  
Constructed Wetland ◽  
Suspended Solids ◽  
Experimental Period ◽  
Pilot Scale ◽  
Application Rate ◽  
Surface Flow ◽  
Laboratory Scale ◽  
Application Rates ◽  
Media Component ◽  
Scale Experiment

Experiments were carried out in a horizontal gravel media filter (GMF) with media size ranging from 5-40 mm. Such gravel-based, sub-surface flow units have been used in both planted and unplanted formats in a range of constructed wetland systems. This GMF was subjected to various hydraulic application rates ranging from 1 m3/(m2.d) to 36 m3/(m2.d) over a twc-year period. The range of suspended solids (SS) concentration was 2-36 mg/l and that of turbidity (NTU) was 3-44 during the experimental period. The average removal of suspended solids varied from 30-86%. It was observed that SS was reduced by a maximum of 86% at an application rate of 13m3/(m2.d), within the above noted SS range. An additional laboratory scale experiment was carried out with artificially grown algae in a vertical perspex tube of 190 mm inner diameter (I.D.) in upward flow condition. Results from the laboratory scale and pilot scale experiments are presented and discussed. The study demonstrates that a constructed wetland format with a subsurface flow and horizontal gravel media component could be used as an alternative method for reducing suspended solids from maturation pond effluent

Nitrogen and phosphate mass balance in a sub-surface flow constructed wetland for treating municipal wastewater

2008 ◽  
Vol 32 (1) ◽  
pp. 81-89 ◽  
Author(s):  
A.K.C. Chung ◽  
Y. Wu ◽  
N.F.Y. Tam ◽  
M.H. Wong
Keyword(s):  
Mass Balance ◽  
Constructed Wetland ◽  
Municipal Wastewater ◽  
Surface Flow

Treatment efficiency of a hybrid constructed wetland system for municipal wastewater and its suitability for crop irrigation

2018 ◽  
Vol 20 (11) ◽  
pp. 1152-1161 ◽  
Author(s):  
Zeshan Ali ◽  
Ashiq Mohammad ◽  
Yousaf Riaz ◽  
Umar Masood Quraishi ◽  
Riffat Naseem Malik
Keyword(s):  
Constructed Wetland ◽  
Municipal Wastewater ◽  
Treatment Efficiency ◽  
Wetland System ◽  
Crop Irrigation

Seasonal treatment efficiency of surface flow constructed wetland receiving high nitrogen content wastewater

2012 ◽  
Vol 48 (1-3) ◽  
pp. 9-16 ◽  
Author(s):  
Soyoung Lee ◽  
Marla C. Maniquiz ◽  
Jiyeon Choi ◽  
Joo-Hyon Kang ◽  
Sangman Jeong ◽  
...  
Keyword(s):  
Nitrogen Content ◽  
Constructed Wetland ◽  
Surface Flow ◽  
High Nitrogen Content ◽  
Treatment Efficiency ◽  
High Nitrogen

Municipal wastewater treatment with pond–constructed wetland system: a case study

2005 ◽  
Vol 51 (12) ◽  
pp. 325-329 ◽  
Author(s):  
X. Wang ◽  
X. Bai ◽  
J. Qiu ◽  
B. Wang
Keyword(s):  
Constructed Wetland ◽  
Municipal Wastewater ◽  
Municipal Wastewater Treatment ◽  
Oxidation Pond ◽  
System A ◽  
Treated Effluent ◽  
Wetland System ◽  
Oxidation Ponds ◽  
Better Than

The performance of a pond–constructed wetland system in the treatment of municipal wastewater in Kiaochow city was studied; and comparison with oxidation ponds system was conducted. In the post-constructed wetland, the removal of COD, TN and TP is 24%, 58.5% and 24.8% respectively. The treated effluent from the constructed wetland can meet the Chinese National Agricultural and Irrigation Standard. The comparison between pond–constructed wetland system and oxidation pond system shows that total nitrogen removal in a constructed wetland is better than that in an oxidation pond and the TP removal is inferior. A possible reason is the low dissolved oxygen concentration in the wetland. Constructed wetlands can restrain the growth of algae effectively, and can produce obvious ecological and economical benefits.

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