Reversing Clogging in Vertical-Flow Constructed Wetlands by Backwashing Treatment

2010 ◽  
Vol 129-131 ◽  
pp. 1064-1068
Author(s):  
Fei Ma ◽  
Li Jiang ◽  
Ting Zeng
Keyword(s):  
Waste Water ◽  
Hydraulic Conductivity ◽  
Constructed Wetlands ◽  
Constructed Wetland ◽  
Removal Rate ◽  
Pollutant Removal ◽  
Vertical Flow ◽  
Vertical Flow Constructed Wetlands ◽  
The World ◽  
Design Guidance

More and more constructed wetland CW) were used to treat waste water in the world for its advantage on cheaper and efficiency. CW would clog for improper design or imperfect management, so application for it was limited. The purpose of this paper is that using backwashing method resolve filter media clogging problem which is an intractable matter in constructed wetlands project. The effects of the backwashing treatment on pollutant removal, as well as the influence on characteristics of hydraulics of wetlands, were studied. The experimental results indicate that CW hydraulic conductivity, hydraulic resistance time and removal rate of COD increased after backwashing. This paper confirmed that backwashing method can reverse clogging in vertical-flow constructed wetlands, and provided design guidance for applying backwashing method to treat clogging vertical-flow constructed wetlands.

Study on Biofortification in Vertical Flow Constructed Wetland

2014 ◽  
Vol 955-959 ◽  
pp. 2570-2573
Author(s):  
Ji Ku Zhang ◽  
Hui Ting Shao ◽  
Yue Ming ◽  
Hui Ye Wang
Keyword(s):  
Constructed Wetlands ◽  
Constructed Wetland ◽  
Loading Rate ◽  
Removal Rate ◽  
Nitrifying Bacteria ◽  
Vertical Flow ◽  
Microbial Inoculants ◽  
Vertical Flow Constructed Wetlands ◽  
Technology And Economy ◽  
Number Of Bacteria

The methods of dosing composite microbial inoculants are used in vertical flow constructed wetlands for biofortification. The removal of the main pollution indicators by substrate microorganisms was studied. The results show that compared with the blank system, the number of bacteria and nitrifying bacteria was higher in the substrate of constructed wetland by biofortification. At the hydraulic loading rate (HLR) of about 0.8 m3/(m2·d), relationship between total number of bacteria and the removal rate of COD was significant in Device A and Device B. Relationship with TP removal rate is not evident. Correlation between the number of nitrifying bacteria and TN removal rate was obvious. The biofortification is feasible on technology and economy.

Installation of a bioelectrochemical system as a pre-cleaner in a constructed wetland with higher pollutant loading under continuous mode

2020 ◽  
Vol 6 (12) ◽  
pp. 3326-3340
Author(s):  
Manoj Kumar ◽  
Rajesh Singh
Keyword(s):  
Constructed Wetlands ◽  
Constructed Wetland ◽  
Municipal Wastewater ◽  
Vertical Flow ◽  
Continuous Mode ◽  
Bioelectrochemical System ◽  
Two Phase ◽  
Pollutant Loading ◽  
Vertical Flow Constructed Wetlands

In this study, two-phase continuous vertical flow constructed wetlands were installed with a pre-cleaner bioelectrochemical system for the removal of NH4+-N (60.41–85.78%), NO3−-N (25.55–35.18%), TN (57.80–84.65%), TKN (37.24–70.08%), PO43−-P (38.89–63.40%), SO42− (49.53–76.06%), and COD (25.83–74.70%) from municipal wastewater.

Correlation Studies of Dissolved Oxygen in the IVCW System Changes and Removal of Nitrogen

2012 ◽  
Vol 610-613 ◽  
pp. 417-421
Author(s):  
Ji Ku Zhang ◽  
Yue Lang ◽  
Ming Jie Li
Keyword(s):  
Dissolved Oxygen ◽  
Constructed Wetlands ◽  
Total Nitrogen ◽  
Constructed Wetland ◽  
Flow Direction ◽  
Vertical Flow ◽  
Correlation Studies ◽  
Vertical Flow Constructed Wetlands ◽  
Vertical Flow Constructed Wetland ◽  
System Changes

Experiment simulates the integrated vertical flow constructed wetland (IVCW) operation of the system, discusses the trend of Dissolved Oxygen (DO) within the system and the relativity of DO and removing nitrogen. The results show that NH4+-N, NO3—-N and DO decrease along the flow direction in the integrated vertical flow constructed wetlands; NO3—-N increased and then decreased along the process; because of the DO of upstream pool is low, so the Total Nitrogen (TN) removing process occurs mainly in the downstream pool.

scholarly journals The Effects of Plants on Pollutant Removal, Clogging, and Bacterial Community Structure in Palm Mulch-Based Vertical Flow Constructed Wetlands

2019 ◽  
Vol 11 (3) ◽  
pp. 632 ◽  
Author(s):  
Marina Carrasco-Acosta ◽  
Pilar Garcia-Jimenez ◽  
José Alberto Herrera-Melián ◽  
Néstor Peñate-Castellano ◽  
Argimiro Rivero-Rosales
Keyword(s):  
Community Structure ◽  
Bacterial Community ◽  
Constructed Wetlands ◽  
Bacterial Community Structure ◽  
Rflp Analysis ◽  
Domestic Wastewater ◽  
Experimental Period ◽  
Pollutant Removal ◽  
Vertical Flow ◽  
Vertical Flow Constructed Wetlands

In this study, the effects of plants on the performance and bacterial community structure of palm mulch-based vertical flow constructed wetlands was studied. The wetlands were built in August 2013; one of them was planted with Canna indica and Xanthosoma sp., and the other one was not planted and used as a control. The experimental period started in September 2014 and finished in June 2015. The influent was domestic wastewater, and the average hydraulic surface loading was 208 L/m2d, and those of COD, BOD, and TSS were 77, 57, and 19 g/m2d, respectively. Although the bed without plants initially performed better, the first symptoms of clogging appeared in December 2014, and then, its performance started to fail. Afterwards, the wetland with plants provided better removals. The terminal restriction fragment length polymorphism (T-RFLP) analysis of Enterococci and Escherichia coli in the effluents suggests that a reduction in their biodiversity was caused by the presence of the plants. Thus, it can be concluded that the plants helped achieve better removals, delay clogging, and reduce Enterococci and E. coli biodiversity in the effluents.

scholarly journals How to treat raw sewage with constructed wetlands: an overview of the French systems

2005 ◽  
Vol 51 (9) ◽  
pp. 11-21 ◽  
Author(s):  
P. Molle ◽  
A. Liénard ◽  
C. Boutin ◽  
G. Merlin ◽  
A. Iwema
Keyword(s):  
Constructed Wetlands ◽  
Pollutant Removal ◽  
Vertical Flow ◽  
Low Level ◽  
Vertical Flow Constructed Wetlands ◽  
And Performance ◽  
Raw Wastewater

The development of vertical flow constructed wetlands treating raw wastewater in France has proved to be very successful over the last 20 years. In view of this a survey was carried out on more than 80 plants in order to study their performance and correct the design if necessary. This study shows that such systems perform well in terms of respecting the goals of both low level outlet COD and SS and nitrification. Pollutant removal performance in relation to the loads handled and the specific characteristics of the plants were investigated. Nitrification is shown to be the most sensitive process in such systems and performance in relation to sizing is discussed. Such systems, if well designed, can achieve an outlet level of 60 mg L−1 in COD, 15 mg L−1 in SS and 8 mg L−1 in TKN with an area of 2–2.5 m2.PE−1. The sludge deposit on the first stage must be removed after about 10–15 years.

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