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.

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.

Using Multi-Function Constructed Wetland for Urban Stream Restoration

2011 ◽  
Vol 121-126 ◽  
pp. 3072-3076
Author(s):  
Chun Yi Wu ◽  
Yu Tung Fu ◽  
Zong Han Yang ◽  
Chih Ming Kao ◽  
Yao Ting Tu
Keyword(s):  
Water Quality ◽  
Quality Improvement ◽  
Constructed Wetland ◽  
Stream Water ◽  
Urban Stream ◽  
Natural Ecosystem ◽  
Stream Water Quality ◽  
Water Quality Improvement ◽  
The Mean ◽  
Wetland System

In 2007, a 2.8-ha multi-function constructed wetland was successfully built in Pingtung County, Taiwan to improve the water quality of local stream and ecosystem of the surrounding environment. The mean inflow rate was approximately 1,350 m3/day. The major influents of the wetland come from the local drainage ditches and streams mainly containing returned water from upstream farmlands and secondary wastewater from hog farms located in the upper catchment of the wetland. Thus, the influents contain moderate to high concentrations of organics and nutrients. The mean measured hydraulic loading rate, hydraulic retention time, water depth, and total volume of wetland system were 0.1 m/day, 5.5 days, 0.7 m, and 7,800 m3, respectively. In this study, water, sediment, and plant samples were collected and analyzed quarterly for each wetland basin during the two-year investigation period. Results show that more than 77% of total coliforms (TC), 78% of biochemical oxygen demand (BOD), 88% of total nitrogen (TN), and 96% of ammonia nitrogen were removed via the constructed wetland system. Thus, the wetland system has a significant effect on water quality improvement and is able to remove most of the pollutants from the local stream through natural attenuation mechanisms. Except for stream water quality improvement and rehabilitating the natural ecosystem, this wetland also offers more water assessable eco-ponds and eco-gardens for public. This constructed wetland has become one of the most successful multi-function constructed wetlands in Taiwan.

scholarly journals Artificial floating islands for water quality improvement

2017 ◽  
Vol 25 (3) ◽  
pp. 350-357 ◽  
Author(s):  
Yueya Chang ◽  
He Cui ◽  
Minsheng Huang ◽  
Yan He
Keyword(s):  
Water Quality ◽  
Quality Improvement ◽  
Constructed Wetlands ◽  
Oxygen Demand ◽  
Key Factors ◽  
Water Quality Improvement ◽  
Factors Influencing ◽  
Wetland Treatment ◽  
Improve Water Quality

Artificial floating islands (AFIs) are a variation of wetland treatment systems for water quality improvement. This paper provides a review concerning AFIs in terms of their development, classification, and applications in the removal of nutrients, heavy metals, and chemical oxygen demand on waterways. The role of microorganisms, aquatic plants, and aquatic animals in AFIs for water decontamination and purification was also discussed. Additionally, some key factors influencing the AFIs’ performances were discussed and comparisons between AFIs and constructed wetlands were reviewed. Finally, further perspectives of artificial floating islands were identified to possibly improve their performances. The understanding of the mechanisms in AFIs that drive removal of various contaminants to improve water quality is crucial, and is also highlighted in this paper.

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.

Designing a Constructed Wetland for the Detention of Agricultural Runoff for Water Quality Improvement

2009 ◽  
Vol 38 (6) ◽  
pp. 2458-2467 ◽  
Author(s):  
Eddie P. Millhollon ◽  
Paul B. Rodrigue ◽  
James L. Rabb ◽  
Danny F. Martin ◽  
Russell A. Anderson ◽  
...  
Keyword(s):  
Water Quality ◽  
Quality Improvement ◽  
Constructed Wetland ◽  
Agricultural Runoff ◽  
Water Quality Improvement

scholarly journals General trends in freshwater ecological restoration practice in China over the past two decades: the driving factors and the evaluation of restoration outcome

2020 ◽  
Author(s):  
Juan Wu ◽  
Yanran Dai ◽  
Shuiping Cheng
Keyword(s):  
Water Quality ◽  
Quality Improvement ◽  
Ecosystem Services ◽  
Ecological Restoration ◽  
Land Reclamation ◽  
Outcome Evaluation ◽  
Driving Factors ◽  
Freshwater Ecosystem ◽  
Water Quality Improvement ◽  
The Past

Abstract Background Although freshwater ecological restoration (FER) has undergone an immense development in China either in the number of projects or in the spatial scale of implementations, a dearth of clear and comprehensive trends in this field is still a particular concern. We conducted a literature survey through searching the database of Web of Science between 1998-2017.Results A total of 2047 publications were hit and 198 of them were finally retained after manual screening. The number of studies in this field has been steadily increasing in recent years and their provincial distribution is positively correlated with GDP growth and the investment to pollution control and protection, suggesting that economic development is a key driving factor of FER practice. Among the remained articles, nearly half (46.5%) focus on lake ecosystems, and 34.8% and 32.8% of the studies believe that land reclamation and eutrophication are the top two causes of freshwater ecosystem degradation. The overarching target of the restoration is biodiversity increase (31.4%), followed by water quality improvement (24.7%) and ecosystem services (23.9%). Revegetation is the dominant restoration approach (40.9%). Reference sites for assessment of restoration projects are normally control areas or locations without intervention (60%), or the status of the targeted sites before the interventions. For the restoration outcome evaluation, 86% of the studies present positive outcomes in terms of water quality improvement, and 79% have improvement in biological features. The most frequently monitored organisms are macrophytes (31%), then followed by benthos as indicators of ecological condition.Conclusions The literature research indicated that economic growth, water pollution and investment into environmental protection are the main driving factors of FER practice in China. Additionally, the effort of restoration and evaluation over the past two decades has not been limited to improving hydrological function and water quality, but also pay increasingly more attention to biological processes and ecological integrity, and further the ecosystem services in recent years. However, the lack of long-term monitoring and socioeconomic attributes considered in restoration success assessments are still particular issues needed to be addressed in the future FER researches and projects.

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