Effect on Treating Urban Wastewater Process by Constructed Wetland Method

2013 ◽  
Vol 726-731 ◽  
pp. 1778-1781
Author(s):  
Jian She Yang ◽  
Xiao Dan Ke

Constructed wetland conduct technology is a kind of artificialgovernable and engineered wetland system. A multiplied technology combination of "Hydrolysis precipitation, Contact oxidation and Constructed wetland" has been applied to conduct the domestic sewage of the towns, and the combination of that, the treatment effect and the working cost have been discussed here. The testing results of outlet water quality indexes showed as following, the removal rate of the CODCr was reach to 77.8%, the removal rate of the BOD5 was reach to 83.3%, the removal rate of the T-P was reach to 87%, the removal rate of the SS was reach 80% and the removal rate of the NH3-N was reach 67%.

2005 ◽  
Vol 51 (12) ◽  
pp. 325-329 ◽  
Author(s):  
X. Wang ◽  
X. Bai ◽  
J. Qiu ◽  
B. Wang

The performance of a pond–constructed wetland system in the treatment of municipal wastewater in Kiaochow city was studied; and comparison with oxidation ponds system was conducted. In the post-constructed wetland, the removal of COD, TN and TP is 24%, 58.5% and 24.8% respectively. The treated effluent from the constructed wetland can meet the Chinese National Agricultural and Irrigation Standard. The comparison between pond–constructed wetland system and oxidation pond system shows that total nitrogen removal in a constructed wetland is better than that in an oxidation pond and the TP removal is inferior. A possible reason is the low dissolved oxygen concentration in the wetland. Constructed wetlands can restrain the growth of algae effectively, and can produce obvious ecological and economical benefits.


2013 ◽  
Vol 295-298 ◽  
pp. 1057-1061 ◽  
Author(s):  
Chang Bing Ye ◽  
Zhi Ming Zhou ◽  
Ke Zhao ◽  
Qin Liu

To solve the problem of short-circuit of individual current constructed wetland, a baffled constructed wetland was designed and applied to treat domestic sewage by our research group. The wetland plants were composed of Eichhormia crassipes, Oenanthe javanica, Cyperusalternifolius, Phragmites communis and Aquatic. The results of 18 month indicated that the optimal hydraulic load of baffled constructed wetland was 2.0~2.2 m3/(m2•d). At the hydraulic load of 2.0m3/(m2•d), the COD, TN and TP removal rates of baffled constructed wetland could be over 76.40%, 76.12%, 65.37%, respectively, at 24°C. When the temperature decreased to 12°C, the COD, TN, TP removal rates of system decreased to 67.56%、62.75% and 61.33%, respectively; The SS removal rate of the first 6 compartments was about 79.5% and that of system could maintain 87.18% during the operation of system. Based on the results of trial, the mechanisms of extending the baffled constructed wetland's operational life was owed to high efficient SS removal rate of the first 6 compartments which was used as constructed wetland and anaerobic baffled reactor (ABR). As a result, the long-term stable operation of system in treatment of domestic sewage was explained with extending about 5 times service life than that of individual current constructed wetland. The mechanisms of higher efficiency of baffled constructed wetland in treatment of domestic sewage were owed to the longer flow line of system and the up-down flow of domestic sewage makes pollutant more intimate contact with roots of wetland plants.


Author(s):  
Shalini Saxena

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.


2010 ◽  
Vol 62 (10) ◽  
pp. 2408-2418 ◽  
Author(s):  
C. Y. Wu ◽  
J. K. Liu ◽  
S. H. Cheng ◽  
D. E. Surampalli ◽  
C. W. Chen ◽  
...  

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.


2012 ◽  
Vol 518-523 ◽  
pp. 1969-1972
Author(s):  
Xiao Fang Yue ◽  
Bo Liu ◽  
Lin Fang ◽  
Chang Kun Liu

In this paper, the performance of the constructed rapid infiltration system ( CRI ) for removal of organic pollutants of domestic sewage was investigated. The results showed that the system had higher efficiency of CODCr removal. The removal rate of CODCr was 86.1% by constructed rapid infiltration system without carbonized sludge , 91.8% with carbonized sludge. The system overcomes the disadvantage of traditional wastewater rapid infiltration land treatment system ( RI ) that the hydraulic load is low, but retains the advantages that the solution process are the low cost, the ease of processing, less energy consumption and good water quality.


2019 ◽  
pp. 297-305
Author(s):  
Hanna Obarska-Pempkowiak ◽  
Katarzyna Klimkowska

In the last decade constructed wetlands have become a very popular technology for removal of contaminants from domestic sewage. They are also assesed from the point of view of their capacity for removal of toxic heavy metals and organic substances resistant to degradation. Constructed wetland in Przywidz localized about 60 km from Gdansk is a pilot wastewater treatment plant (WWTP) designed for 150 PE (person equivalent). The system consists of two sections: vegetated submerged bed (VSB) with horizontal flow of sewage and a cascade filter situated on a slope of a hill. Domestic sewage after a conventional pretreatment ( consists of an Imhoff tank and a trickling filter) is pumped to the VSB filter located on slope of the hill. Total area of constructed wetland is about 870 m2. In the period 1995-98 the measurments of several heavy metals (Cd, Cu, Pb) were carried out. These measurments were carried out in inflowing and outflowing sewage and as well in samples collected from each section of constructed wetland system. In particular analysis of sediment collected in ditches of the cascade filter, filling material of the dykes, VSB filter and plants were carried out. It was found out that content of heavy metals in suspended soil decreased along the course of treatment, starting from VSB filter, through the first ditch to the last ditch. Measurable concentration of dissolved heavy metals were found in sewage collected from several subsequent ditches. The main mechanism of removal on particular matter in subsequent ditches was sorption.


2013 ◽  
Vol 295-298 ◽  
pp. 1303-1306
Author(s):  
Min Lu ◽  
Shun Teng Liu ◽  
Wen Feng Kang ◽  
Ke Ke Li ◽  
Jie Zhao ◽  
...  

By adopting the constructed wetland system of surface flow, the purification effects of different residence time of wastewater, different constructed wetland plants and their synergistic effect are studied in DO disposal in living wastewater. The results show that the best plant combination in purifying DO is that of Phragmites communis and Typha oriental,followed by that of Phragmites communis, and that of Arundo donax and Typha oriental is lowest.


Sign in / Sign up

Export Citation Format

Share Document