scholarly journals Integrating MFT-qPCR techniques in constructed wetland faecal bacterial purification monitoring; a case of a typical tropical hybrid constructed wetland system

2018 ◽  
Vol 78 (9) ◽  
pp. 2008-2018 ◽  
Author(s):  
Donde Oscar Omondi ◽  
Muia Anastasia Wairimu ◽  
Makindi Stanley Maingi ◽  
Onyango Godfrey Otieno ◽  
Kibet Caroline Jepkorir ◽  
...  
Keyword(s):  
Wastewater Treatment ◽  
Constructed Wetlands ◽  
Constructed Wetland ◽  
Membrane Filtration ◽  
Pathogenic Bacteria ◽  
Quantitative Polymerase Chain Reaction ◽  
Health Concern ◽  
Human Pathogens ◽  
Purification Efficiency ◽  
Wetland System

Abstract The sanitation control of pathogens in the tropical effluents needs much more attention to ensure ecosystem health integrity and the safety of human health. The common use of chemicals in achieving this in wastewater treatment has remained unsustainable due to much health concern. Indeed, based on the numerous challenges associated with faecal pathogenic bacteria in wastewaters, the focus is now on achieving higher purification efficiencies in the elimination of the human pathogens from wastewater through eco-sustainable systems such as constructed wetlands (CWs). Hence, the need to explore the application of constructed wetlands in wastewater treatment under specific local environmental conditions for accurate understanding and improved treatment efficiency. This study therefore aimed at monitoring constructed wetlands faecal bacteria purification efficiency through integrated non-molecular membrane filtration technique and molecular quantitative polymerase chain reaction (MFT-qPCR) technique. The results showed some shortfall in the treatment system and also proved that integrating MFT-qPCR in faecal bacterial purification monitoring within a constructed wetland system provides a more accurate and reliable outcome. Additionally, the wetland purification efficiency was low (<80%) with the dissolved oxygen posing the strongest influence on faecal pathogenic bacterial purification trend across the wetland. Hence, the need to regularly carry out dredging and macrophyte harvesting as well as the use of holistic and more integrative approaches such as MFT-qPCR in managing and monitoring the performance of CWs in faecal pathogen eradication for improved CWs purification efficiency.

Constructed wetland for water quality improvement: a case study from Taiwan

2010 ◽  
Vol 62 (10) ◽  
pp. 2408-2418 ◽  
Author(s):  
C. Y. Wu ◽  
J. K. Liu ◽  
S. H. Cheng ◽  
D. E. Surampalli ◽  
C. W. Chen ◽  
...  
Keyword(s):  
Water Quality ◽  
Wastewater Treatment ◽  
Constructed Wetlands ◽  
Constructed Wetland ◽  
Water Reuse ◽  
Oxygen Demand ◽  
Sediment Oxygen Demand ◽  
Nucleotide Sequence Analysis ◽  
Sediment Samples ◽  
Wetland System

In Taiwan, more than 20% of the major rivers are mildly to heavily polluted by domestic, industrial, and agricultural wastewaters due to the low percentage of sewers connected to wastewater treatment plants. Thus, constructed or engineered wetlands have been adopted as the major alternatives to clean up polluted rivers. Constructed wetlands are also applied as the tertiary wastewater treatment systems for the wastewater polishment to meet water reuse standards with lower operational costs. The studied Kaoping River Rail Bridge Constructed Wetland (KRRBCW) is the largest constructed wetland in Taiwan. It is a multi-function wetland and is used for polluted creek water purification and secondary wastewater polishment before it is discharged into the Kaoping River. Although constructed wetlands are feasible for contaminated water treatment, wetland sediments are usually the sinks for organics and metals. In this study, water and sediment samples were collected from the major wetland basins in KRRBCW. The investigation results show that more than 97% of total coliforms (TC), 55% of biochemical oxygen demand (BOD), and 30% of nutrients [e.g. total nitrogen (TN), total phosphorus (TP)] were removed via the constructed wetland system. However, results from the sediment analyses show that wetland sediments contained high concentrations of metals (e.g. Cu, Fe, Zn, Cr, and Mn), organic contents (sediment oxygen demand = 1.7 to 7.6 g O2/m2 d), and nutrients (up to 18.7 g/kg of TN and 1.22 g/kg of TN). Thus, sediments should be excavated periodically to prevent the release the pollutants into the wetland system and causing the deterioration of wetland water quality. Results of polymerase chain reaction (PCR), denaturing gradient gel electrophoresis (DGGE), and nucleotide sequence analysis reveal that a variation in microbial diversity in the wetland systems was observed. Results from the DGGE analysis indicate that all sediment samples contained significant amounts of microbial ribospecies, which might contribute to the carbon degradation and nitrogen removal. Gradual disappearance of E. coli was also observed along the flow courses through natural attenuation mechanisms.

Using a constructed wetland for non-point source pollution control and river water quality purification: a case study in Taiwan

2010 ◽  
Vol 61 (10) ◽  
pp. 2549-2555 ◽  
Author(s):  
C. Y. Wu ◽  
C. M. Kao ◽  
C. E. Lin ◽  
C. W. Chen ◽  
Y. C. Lai
Keyword(s):  
Water Quality ◽  
Wastewater Treatment ◽  
Quality Improvement ◽  
Point Source ◽  
River Water ◽  
Constructed Wetlands ◽  
Constructed Wetland ◽  
River Water Quality ◽  
Water Quality Improvement ◽  
Wetland System

The Kaoping River Rail Bridge Constructed Wetland, which was commissioned in 2004, is one of the largest constructed wetlands in Taiwan. This multi-function wetland has been designed for the purposes of non-point source (NPS) pollutant removal, wastewater treatment, wildlife habitat, recreation, and education. The major influents of this wetland came from the local drainage trench containing domestic, agricultural, and industrial wastewaters, and effluents from the wastewater treatment plant of a paper mill. Based on the quarterly investigation results from 2007 to 2009, more than 96% of total coliforms (TC), 48% of biochemical oxygen demand (BOD), and 40% of nutrients (e.g. total nitrogen, total phosphorus) were removed via the constructed wetland system. Thus, the wetland system has a significant effect on water quality improvement and is capable of removing most of the pollutants from the local drainage system before they are discharged into the downgradient water body. Other accomplishments of this constructed wetland system include the following: providing more green areas along the riversides, offering more water assessable eco-ponds and eco-gardens for the public, and rehabilitating the natural ecosystem. The Kaoping River Rail Bridge Constructed Wetland has become one of the most successful multi-function constructed wetlands in Taiwan. The experience obtained from this study will be helpful in designing similar natural treatment systems for river water quality improvement and wastewater treatment.

Construction and maintenance cost analyzing of constructed wetland systems

2011 ◽  
Vol 6 (3) ◽  
Author(s):  
K. Gunes ◽  
B. Tuncsiper ◽  
F. Masi ◽  
S. Ayaz ◽  
D. Leszczynska ◽  
...  
Keyword(s):  
Wastewater Treatment ◽  
Constructed Wetlands ◽  
Constructed Wetland ◽  
Rural Areas ◽  
Subsurface Flow ◽  
Maintenance Cost ◽  
Operational Costs ◽  
Subsurface Flow Constructed Wetland ◽  
Wetland System ◽  
Horizontal Subsurface Flow

Nowadays, use of constructed wetlands for wastewater treatment especially in rural areas has become increasingly preferable. The most important reason behind this fact is its relatively low investment cost over other treatment options depending on economical conditions of the country. Nonetheless, due to lower operational costs of constructed wetlands than other conventional wastewater treatment systems, investment costs could be regarded secondary as of importance. Investment costs could show differences even at regional scale in a country. Choosing a constructed wetland system among “Subsurface Horizontal Flow”, “Subsurface Vertical Flow” or “Free Water Surface Flow”; or designing a hybrid system using concurrent systems plays important role when defining costs of the constructed wetland systems. Due to increasing interest for constructed wetlands since 2003, so many constructed wetland systems have been built in rural parts of Turkey and most of these systems have been designed as horizontal subsurface flow constructed wetland system. As a fact, the cost of horizontal subsurface flow constructed wetlands is comparatively higher than other wetland systems. When different applications in the world are examined, it is observed that mostly horizontal subsurface flow constructed wetland systems are preferred in rural areas. According to the studies within the extent of this work, different constructed wetland types which are built in different regions of Turkey and their expected and realized costs are analyzed and compared with other countries. Moreover, operational costs have been calculated. Consequently, a work to be taken as reference for further scientific studies has been prepared with presented wetland analyses which could be used by especially decision makers and researchers.

scholarly journals Community Wastewater Treatment with Attached Growth Assisted Constructed Wetland Reactor

2017 ◽  
Vol 7 (2 (S)) ◽  
pp. 327
Author(s):  
Nitin Ingole ◽  
Mangesh Gulhane
Keyword(s):  
Wastewater Treatment ◽  
Constructed Wetlands ◽  
Constructed Wetland ◽  
Operating Conditions ◽  
Laboratory Scale ◽  
Scale Model ◽  
Reactor Model ◽  
Attached Growth ◽  
Growth System ◽  
Wetland System

Constructed wetlands are systems of artificial wastewater treatment which consists of shallow ponds or channels that have been planted with aquatic plants. The treatment is based on the natural, biological, physical and chemical treatment of wastewater. The technique is reported to be cost effective as compared to other methods. The constructed wetlands have impermeable clay or synthetic coatings and artificial structures for controlling the direction of flow, liquid retention time and the water level. However, there are certain limitations of constructed wetland system, which need improvement for its wide adoptability. As such the effort was made to assist the constructed wetland system with attached growth system with the aim to design an economical and user friendly waste water treatment option for the small community. The laboratory scale model was fabricated using GI sheet of thickness 0.5 mm. The overall capacity of the model was 275 L. The laboratory scale reactor model consisted of four compartments out of which first three compartments were based on attached growth system and the fourth compartment acted as constructed wetland reactor. All the three compartments were packed with different types of artificial, semi-artificial and natural media. The fourth compartment consisted of media packed from bottom as aerocon stone layers 03 in numbers followed by snail shell, followed by a soil layer of 80 mm thick which holds the plants in rows. The reactor was operated as continuous flow reactor with varying detention time and change of different type of media packed in the reactor. The performance of Customized Constructed Wetland reactor was observed under various operating conditions for removal of BOD, COD and TS parameters. The paper presents the details regarding the development of the reactor model, operation of the reactor model and results obtained during the course of study. The paper also cover the discussion regarding the improved performance of reactor noted during the study and adoptability of the developed reactor model for community waste treatment.

Enhancement of the performance of constructed wetlands for wastewater treatment in winter: the effect of Tubifex tubifex

RSC Advances ◽  
2016 ◽  
Vol 6 (41) ◽  
pp. 34841-34848 ◽  
Author(s):  
Yan Kang ◽  
Jian Zhang ◽  
Huijun Xie ◽  
Zizhang Guo ◽  
Pengfei Li ◽  
...  
Keyword(s):  
Wastewater Treatment ◽  
Constructed Wetlands ◽  
Constructed Wetland ◽  
Water Purification ◽  
Tubifex Tubifex ◽  
Batch Systems ◽  
Potential Use

An improved constructed wetland (CW) with the addition ofTubifex tubifexin winter was studied in laboratory batch systems. The outcomes of this study indicate that the potential use ofTubifex tubifexcould improve the ecosystem and water purification by CWs in winter.

scholarly journals EFFICACY OF PHRAGMITE KARKA PLANT IN CONSTRUCTED WETLAND SYSTEM

2015 ◽  
Vol 3 (9SE) ◽  
pp. 1-5
Author(s):  
Shalini Saxena
Keyword(s):  
Water Quality ◽  
Wastewater Treatment ◽  
Quality Improvement ◽  
Constructed Wetland ◽  
Flood Control ◽  
Water Quality Improvement ◽  
The Past ◽  
Wetland Treatment ◽  
Natural Wetlands ◽  
Wetland System

Wetlands, either constructed or natural, offer a cheaper and low-cost alternative technology for wastewater treatment. A constructed wetland system that is specifically engineered for water quality improvement as a primary purpose is termed as a ‘Constructed Wetland Treatment System’ (CWTS). In the past, many such systems were constructed to treat low volumes of wastewater loaded with easily degradable organic matter for isolated populations in urban areas. However, widespread demand for improved receiving water quality, and water reclamation and reuse, is currently the driving force for the implementation of CWTS all over the world. Recent concerns over wetland losses have generated a need for the creation of wetlands, which are intended to emulate the functions and values of natural wetlands that have been destroyed. Natural characteristics are applied to CWTS with emergent macrophyte stands that duplicate the physical, chemical and biological processes of natural wetland systems. The number of CWTS in use has very much increased in the past few years. The use of constructed wetlands is gaining rapid interest. Most of these systems cater for tertiary treatment from towns and cities. They are larger in size, usually using surface-flow system to remove low concentration of nutrient (N and P) and suspended solids. However, in some countries, these constructed wetland treatment systems are usually used to provide secondary treatment of domestic sewage for village populations. These constructed wetland systems have been seen as an economically attractive, energy-efficient way of providing high standards of wastewater treatment by the help of Phragmite karka plant. Typically, wetlands are constructed for one or more of four primary purposes: creation of habitat to compensate for natural wetlands converted for agriculture and urban development, water quality improvement, flood control, and production of food and fiber.

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