Pathogen Removal in Constructed Wetlands

2020 ◽  
pp. 431-445
Author(s):  
Richard M. Gersberg ◽  
R. A. Gearheart ◽  
Mike Ives
Keyword(s):  
Constructed Wetlands ◽  
Pathogen Removal

Mechanisms of pathogen removal by macrophytes in constructed wetlands

2017 ◽  
Vol 6 (1) ◽  
pp. 135-144 ◽  
Author(s):  
Richwell Alufasi ◽  
Jephris Gere ◽  
Ereck Chakauya ◽  
Phiyani Lebea ◽  
Wilson Parawira ◽  
...  
Keyword(s):  
Constructed Wetlands ◽  
Pathogen Removal

scholarly journals Disinfection of constructed wetland effluent by in situ electrochemical chlorine production for water reuse

2021 ◽  
Author(s):  
Suanny Sophia Mosquera Romero ◽  
Antonin Prévoteau ◽  
Jan B.A. Arends ◽  
Diederick Rousseau ◽  
Luis Dominguez-Granda ◽  
...  
Keyword(s):  
Constructed Wetlands ◽  
Constructed Wetland ◽  
Water Reuse ◽  
Additional Treatment ◽  
Pathogen Removal

Constructed wetlands (CW) are globally used for the treatment of wastewater. Due to various causes, often the water is not fully treated in terms of pathogen removal requiring additional treatment....

scholarly journals Quantifying the Log Reduction of Pathogenic Microorganisms by Constructed Wetlands: A Review

Proceedings ◽  
2019 ◽  
Vol 48 (1) ◽  
pp. 9
Author(s):  
Sotirios Paraskevopoulos ◽  
Patrick Smeets
Keyword(s):  
Wastewater Treatment ◽  
Case Studies ◽  
Constructed Wetlands ◽  
Water Reuse ◽  
Fecal Coliforms ◽  
Operational Parameters ◽  
Pathogen Removal ◽  
Knowledge Gaps ◽  
Climatic Zones ◽  
Conventional Wastewater Treatment

Over the last 30 years, constructed wetlands (CWs) have been used as an alternative, cost-efficient way of treating wastewater, often in combination with conventional wastewater technologies. When CWs are attached at the end of conventional wastewater treatment plants, they treat the effluent and thus provide a polishing step. However, recent studies have shown that when CWs are used as the main wastewater treatment method for the agricultural reuse of effluents, they perform poorly on meeting the accepted limit of microbial contamination. Moreover, CWs are increasingly used within the scope of the circular economy and water reuse applications. Therefore, there is a need for a comprehensive exploration of the performance of CWs on pathogen removal. This paper explores relevant case studies regarding pathogen removal from constructed wetlands to create a comprehensive dataset that provides a complete overview of CWs performance under various conditions. After a systematic literature review, a total of 48 case studies were qualified for both qualitative and quantitative analyses. From the dataset, the general performance, optimal conditions, and knowledge gaps were identified. The review confirmed that constructed wetlands (as a standalone treatment) cannot meet the accepted limits of pathogen removal. However, they can be a credible choice for wastewater polishing when they are combined with conventional wastewater treatment systems. Regarding the most common indicators that were recorded, the removal of Escherichia coli ranged between 0.01–5.6 log; the removal of total and fecal coliforms was 0.2–5.32 log and 0.07–6.08 log, respectively; while the removal of fecal streptococci was 0.2–5.2 log. The great variability of pathogen removal indicates that the complexity of CWs makes it difficult to draw robust conclusions regarding their removal efficiency. Potential correlations were identified between influent and effluent concentrations, as well as between log removal and hydraulic characteristics. Additionally, no correlations between pathogen removal and temperature/climatic zones were found since average pathogen removal per country showed high variation throughout the various climatic zones. The dataset can be used as a benchmark of CWs’ performance as a barrier against the spreading of pathogens in the environment. The knowledge gaps identified in this review can provide direction for further research. Finally, a potential meta-analysis of the dataset using statistical analysis can pave the way for a better understanding of the design and operational parameters of CWs in order to fine-tune and quantify the factors that influence the performance of these systems.

Internalisation of Salmonella spp. by Typha latifolia and Cyperus papyrus in vitro and implications for pathogen removal in Constructed Wetlands

2020 ◽  
pp. 1-13 ◽  
Author(s):  
Richwell Alufasi ◽  
Wilson Parawira ◽  
Alexandros I. Stefanakis ◽  
Phiyani Lebea ◽  
Ereck Chakauya ◽  
...  
Keyword(s):  
Constructed Wetlands ◽  
Typha Latifolia ◽  
Cyperus Papyrus ◽  
Pathogen Removal ◽  
Salmonella Spp

Constructed Wetlands for Wastewater Treatment: The New Zealand Experience

1991 ◽  
Vol 24 (5) ◽  
pp. 247-253 ◽  
Author(s):  
R. Bhamidimarri ◽  
A. Shilton ◽  
I. Armstrong ◽  
P. Jacobson ◽  
D. Scarlet
Keyword(s):  
Wastewater Treatment ◽  
New Zealand ◽  
Constructed Wetlands ◽  
Reaction Rates ◽  
Surface Flow ◽  
Septic Tank ◽  
Small Scale ◽  
Pathogen Removal ◽  
Small Communities ◽  
Ecological Mechanisms

The use of constructed wetlands which mimic natural marshlands, represents an innovative approach to wastewater treatment. They make use of diverse ecological mechanisms to renovate wastewater. They are inexpensive to construct and operate with minimal energy requirements. Unlike the conventional technologies, wetlands provide low volumetric reaction rates and therefore are suitable for small-scale applications. The majority of constructed wetlands in New Zealand are used for the treatment of domestic wastewaters from small communities for secondary treatment and pathogen removal. There are over 20 constructed wetlands in New Zealand receiving wastewater flow rates ranging from 7.5m3/day to around 4500m3/day. Both surface-flow and subsurface-flow wetlands are used. The performance data from three wetland systems treating septic tank effluents are presented and their treatment efficiences are discussed.

Mineralisation and pathogen removal in gravel bed hydroponic constructed wetlands for wastewater treatment

1995 ◽  
Vol 32 (3) ◽  
pp. 49-58 ◽  
Author(s):  
J. Williams ◽  
M. Bahgat ◽  
E. May ◽  
M. Ford ◽  
J. Butler
Keyword(s):  
Constructed Wetlands ◽  
Suspended Solids ◽  
Significant Contribution ◽  
Sewage Treatment ◽  
Secondary Treatment ◽  
Strongly Correlated ◽  
Pathogen Removal ◽  
Effluent Quality ◽  
Gravel Bed ◽  
The Uk

Gravel Bed Hydroponics (GBH) is a constructed wetland system for sewage treatment which has proved effective for tertiary treatment in the UK and secondary treatment in Egypt. Significant improvements in effluent quality have been observed in 100 m long field scale beds planted with Phragmites australis, resulting in large reductions in BOD, suspended solids and ammoniacal N. For such GBH beds, operating optimally with a residence time of about 6 hours, 2 to 3 log cycle reductions in the counts of indicator bacteria, certain bacterial pathogens and viruses are typically obtained. However, the efficiency of mineralisation was strongly influenced by flow-rate and the prevailing temperature. In addition, in the UK, overloading of the treatment system reduced the efficiency of removal of faecal coliforms, probably due to decreased adsorption to biofilms. Faecal coliform counts were also more strongly correlated to BOD than suspended solids. As a secondary treatment process, pathogen removal was consistently better in Egypt than the UK. Although GBH constructed wetlands do not fully satisfy the WHO guidelines for unrestricted irrigation, they can make a significant contribution to the control of pathogens in developing countries.

Sign in / Sign up

Export Citation Format

Share Document