ISOLATION AND IDENTIFICATION OF AEROBIC MICROBIAL COMMUNITY TREATING BENZENE FROM A CONSTRUCTED WETLAND SYSTEM

The main objective of this study was to isolate and identify the aerobic bacteria in bacterial community of constructed wetland in Vietnam, which were spiked with benzene. For this target, four random samples of rhizosphere soil of phragmiteskarkas from constructed wetlands in Vietnam were collected and mixed together. The soil sample was labeled VS. Bacteria in the sample was grown in 80 mg/L benzene liquid media with optimal conditions of temperature and shaken to find out whether bacteria in the sample can remove benzene or not. The result showed that bacteria in the sample can survive and treat benzene well. Strains of bacteria were isolated through incubation in Burk’s medium mixed with benzene. The strain named VS1 from VS sample was obtained. The strain adapted well in agar medium containing benzene as sole carbon source. Through molecular methods, VS1 was identified as PandoraeapnomenusaCM25.

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

Water Science & Technology ◽

10.2166/wst.2010.492 ◽

2010 ◽

Vol 62 (10) ◽

pp. 2408-2418 ◽

Cited By ~ 9

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.

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The Elliot Ditch Constructed Wetlands

Journal of Green Building ◽

10.3992/jgb.2.3.79 ◽

2007 ◽

Vol 2 (3) ◽

pp. 79-87

Author(s):

Aaron A Zambo

Keyword(s):

Constructed Wetlands ◽

Constructed Wetland ◽

Agricultural Runoff ◽

Load Reduction ◽

Nitrogen And Phosphorus ◽

Detention Time ◽

Wetland System ◽

Contaminant Load

The purpose of this experiment was to determine the contaminant load reduction incurred using a constructed wetland with an average hydraulic detention time of five days in treating agricultural runoff. The main contaminants present in the runoff were nitrogen and phosphorus from agricultural fertilizers. The findings of the experiment show that significant contaminant load reduction results can be achieved with a detention time, of as little as five days, in a properly constructed wetland system.

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

Water Science & Technology ◽

10.2166/wst.2010.175 ◽

2010 ◽

Vol 61 (10) ◽

pp. 2549-2555 ◽

Cited By ~ 15

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.

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

Water Science & Technology ◽

10.2166/wst.2018.475 ◽

2018 ◽

Vol 78 (9) ◽

pp. 2008-2018 ◽

Cited By ~ 1

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.

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Application of constructed wetlands to treat some toxic wastewaters under tropical conditions

Water Science & Technology ◽

10.2166/wst.1996.0276 ◽

1996 ◽

Vol 34 (11) ◽

pp. 165-171 ◽

Cited By ~ 14

Author(s):

C. Polprasert ◽

N. P. Dan ◽

N. Thayalakumaran

Keyword(s):

Constructed Wetlands ◽

Constructed Wetland ◽

Free Water ◽

Operating Conditions ◽

Organic Loading ◽

Metal Compounds ◽

Loading Rates ◽

Tropical Conditions ◽

Wetland System ◽

Stems And Leaves

This study evaluated the potential of a free water surface constructed wetland system in treating some toxic wastewaters (i.e. phenolic and heavy metals). In a temperature range of 22–30°C, the constructed wetland units, whose hydraulic retention times (HRT) were 5–7 days, could remove more than 99% of the input phenol when they were operated at or below the organic loading rates (OLR) and influent phenol concentrations of 270 kg COD/(ha.d) and 400 mg/l, respectively. The effluent dissolved oxygen (DO) levels were 4–7 mg/l at OLR of 40–140 kg COD/(ha.d), but these DO levels decreased to 0.2–0.3 mg/l when the OLR were increased to 165–270 kg COD/(ha.d). Under similar operating conditions, the constructed wetland units could remove more than 99% of the applied chromium (Cr) and nickel (Ni), when either the Cr or Ni influent concentrations were 1–50 mg/l. The phenolic and heavy metal compounds were found to accumulate mostly at the roots of Typha, followed by the stems and leaves.

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Application of a constructed wetland for non-point source pollution control

Water Science & Technology ◽

10.2166/wst.2001.0884 ◽

2001 ◽

Vol 44 (11-12) ◽

pp. 585-590 ◽

Cited By ~ 27

Author(s):

C.M. Kao ◽

J.Y. Wang ◽

H.Y. Lee ◽

C.K. Wen

Keyword(s):

Water Quality ◽

Point Source ◽

Constructed Wetlands ◽

Constructed Wetland ◽

Pollution Control ◽

Pistia Stratiotes ◽

Storm Event ◽

Untreated Wastewater ◽

Nps Pollution ◽

Wetland System

In Taiwan, non-point source (NPS) pollution is one of the major causes of impairment of surface waters. The main objective of this study was to evaluate the efficacy of using constructed wetlands on NPS pollutant removal and water quality improvements. A field-scale constructed wetland system was built inside the campus of National Sun Yat-Sen University (located in southern Taiwan) to remove (1) NPS pollutants due to the stormwater runoff, and (2) part of the untreated wastewater from school drains. The constructed wetland was 40 m (L) × 30 m (W) × 1 m (D), which received approximately 85 m3 per day of untreated wastewater from school drainage pipes. The plants grown on the wetland included floating (Pistia stratiotes L.) and emergent (Phragmites communis L.) species. One major storm event and baseline water quality samples were analyzed during the monitoring period. Analytical results indicate that the constructed wetland removed a significant amount of NPS pollutants and wastewater constituents. More than 88% of nitrogen, 81% of chemical oxygen demand (COD), 85% of heavy metals, and 60% of the total suspended solids (TSS) caused by the storm runoff were removed by the wetland system before discharging. Results from this study may be applied to the design of constructed wetlands for NPS pollution control and water quality improvement.

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Construction and maintenance cost analyzing of constructed wetland systems

Water Practice & Technology ◽

10.2166/wpt.2011.043 ◽

2011 ◽

Vol 6 (3) ◽

Cited By ~ 9

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.

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Community Wastewater Treatment with Attached Growth Assisted Constructed Wetland Reactor

IRA-International Journal of Technology & Engineering (ISSN 2455-4480) ◽

10.21013/jte.icsesd201731 ◽

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.

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