AbstractShanghu ecological lake wetland is mostly made up of woody plants. So far, its removal effects on nitrogen and phosphorus are unknown. The removal effects on TN, TP, AmmN and COD in wastewater of Shanghu lake wetland were studied from July, 2008 to May, 2009. The relationship between removal effects on pollutants and temperatures of water body was studied too.192 samples were collected from input point, output point, and 6 points in water body. The results show that the wetland has always a good removal effect on TN, TP and AmmN under different water temperature, the water temperature has influence on removal effects to various extents. First report to removal effects on nitrogen and phosphorus of Shanghu lake wetland and woody plants wetland in China

GuoSheng, Ma

Juan, Chen

Elsevier - Publisher Connector 

Removal Effects on Nitrogen, Phosphorus and COD in Water Body of Shanghu Lake Ecological Wetland in Taihu Lake Watershed 

 Procedia Environmental Sciences  10 ( 2011 )  2665 – 2670 
1878-0296 © 2011 Published by Elsevier Ltd. Selection and/or peer-review under responsibility of Conference ESIAT2011 Organization Committee.
doi: 10.1016/j.proenv.2011.09.414 
Available online at www.sciencedirect.com
 
 
Removal Effects on Nitrogen, Phosphorus and COD in Water 
Body of Shanghu Lake Ecological Wetland in Taihu Lake 
Watershed 
MA GuoSheng1ˈa, CHEN Juan1ˈ 
1 Institute of Eco-environment Protection ˈ, Suzhou Polytechnic College of Agriculture Suzhou, Jiangsu Province, P.R. China 215008 
a email: banail@foxmail.com 
 
Abstract 
Shanghu ecological lake wetland is mostly made up of woody plants. So far, its removal effects on nitrogen and 
phosphorus are unknown. The removal effects on TN, TP, AmmN and COD in wastewater of Shanghu lake wetland 
were studied from July, 2008 to May, 2009. The relationship between removal effects on pollutants and temperatures 
of water body was studied too.192 samples were collected from input point, output point, and 6 points in water body. 
The results show that the wetland has always a good removal effect on TN, TP and AmmN under different water 
temperature, the water temperature has influence on removal effects to various extents. First report to removal effects 
on nitrogen and phosphorus of Shanghu lake wetland and woody plants wetland in China. 
 
© 2011 Published by Elsevier Ltd. Selection and/or peer-review under responsibility of [name organizer] 
 
Keywords: Taihu Lake Watershed, Shanghu Lake Ecological Wetland, Nitrogen and Phosphorus, COD, Removal Effects 
Introduction 
With the acceleration of industrial growth and the increasing population, the natural environment is 
constantly deteriorating. The water pollution is becoming increasingly severe. Over 90 percent of the 
water body in ponds and lakes of city’s parks in China is polluted to some degree, and most of the indexes 
of total nitrogen (TN), total phosphorus˄TP˅ and ammonia nitrogen˄NH3-N˅ are beyond the 
environmental quality standards of level 4 for surface water˷1,2˹. Since 1970s, aquatic plants were given 
attention for searching high effect and low cost wastewater disposal technology. Aquatic plants not only 
have high ornamental value, but also provide purification to eutrophication water body via initiative 
absorption from the water body. So, the wastewater disposal function of aquatic plants and ecological 
wetland has been used and paid attention more and more.  
The Shanghu lake ecological wetland is located at suburban district of Changshu city in Taihu lake 
© 2011 Published by Elsevier Ltd. Selection and/or peer-review under responsibility of Conference ESIAT2011 
Organization Committee.
2011 3rd International Conference on Environmental 
Science and Information Application Technology (ESIAT 2011)
Open access under CC BY-NC-ND license.
Open access under CC BY-NC-ND license.
2666   MA GuoSheng and CHEN Juan /  Procedia Environmental Sciences  10 ( 2011 )  2665 – 2670 
watershed. It is important to local climate, such as temperature and humidity, for improving the city’s 
ecological environment, and for purifying wastewater of Taihu lake watershed. There are no reports about 
the removal effects on non-point source wastewater of the Shanghu lake wetland and the wetland 
constructed by woody plants according to documentary sources until now. It is significance to study on 
removing nitrogen and phosphorus, which have been one of the key factors leading to the eutrophication 
of water bodies, of the Shanghu lake wetland. 
Material and Methods 
Testing location. The Shanghu lake ecological wetland, which is located at suburban district of Changshu 
city in Taihu lake watershed in East China, is one of the top ten city ecological parks and one of the most 
important ecological wetlands in Taihu lake watershed. Its territorial waters area is 800 ha. It has over 
300000 woody plants of 173 families, mostly Pond Cypress (Taxodium ascendens Brongn.), Phragmites 
communis Trin. (Phragmites Trin.) and Cattall Pollen ˄Typhaang ustifolia˅ˈ which formed a kind of 
particular Pond Cypress community forest wetland landscape. 
Testing time. It lasted for nearly one whole year from July 2008 to May 2009; including every period 
when water temperature varies. 
Sampling methods. The 192 samples were taken from water inlet, water outlet, and 6 fixed sampling 
points of lake body individually (Table 1). 
 
Table 1 The sample points distribution in Shanghu lake 
Number 1 2 3 4 5 6 7 8 
Sample 
points Inlet 
lake body 
Outlet 
East lake Dazhai gate 
West 
lake Lajidui 
Tanchun 
bridge 
North 
lake 
Determining methods. COD˄chemical oxygen demand˅, pH, TN, NH3-N and TP were determined 
according to water and wastewater monitor analysis methods (the 4th edition) [2]. COD: used 
Permanganate Index method to determine; pH: used pH meter method to determine; TN, NH3-N and TP˖
used flow injection analysis method to determine; TN, NH3-N, TP and COD removal rate statistical 
methods: TN( NH3-N, TP or COD˅ removal rate =[ inlet TN( NH3-N, TP or COD˅- outlet TN( NH3-N, 
TP or COD˅] /outlet TN( NH3-N, TP or COD˅×100%. 
Results and Analysis 
The removal rate under the different water temperature variables. TN, NH3-N, TP, and water 
temperature were sampled and determined one time individually in July 2008, November 2008, and 
January 2009. The results are shown in Table-2, Table-3 and Table-4. 
Tab. 2 The values of nitrogen and phosphorus from Shanghu lake wetland under 30  water temperatureć  
Sample 
points 
Water  
Temperature [ ]ć  pH NH3-N[mg.m
-3] TN[mg.m-3] TP[mg.m-3] 
Water inlet 30.5 7.87 0.56 2.63 0.10 
Average of 
water body 29.7 8.49 0.33 0.58 0.02 
Water outlet 30.2 8.41 0.06 0.86 0.05 
2667 MA GuoSheng and CHEN Juan /  Procedia Environmental Sciences  10 ( 2011 )  2665 – 2670 
Tab. 3 The values of nitrogen and phosphorus from Shanghu lake wetland under 13  water temperatureć  
Sample points Water  temperature [ ]ć  pH NH3-N[mg.m
-3] TN[mg.m-3] TP[mg.m-3] 
Water inlet 16.4 7.54 1.38 2.63 0.10 
Average of 
water body 13.5 8.40 0.04 0.33 0.05 
Water outlet  13.8 8.24 0.10 0.66 0.04 
Tab. 4 The values of nitrogen and phosphorus from Shanghu lake wetland under 5  water temperatureć  
Sample points Water  temperature [ ]ć  pH NH3-N[mg.m
-3] TN[mg.m-3] TP[mg.m-3] 
Water inlet 5.2 7.71 1.35 2.56 0.19 
Average of 
water body 5.0 8.19 0.06 1.01 0.06 
Water outlet 5.2 8.05 0.08 0.82 0.04 
According to Table 2, Table 3, and Table 4, the removal rates of nitrogen and phosphorus of Shanghu 
lake wetland under varying water temperatures were statistically analyzed. The results are shown in Table 
5 and Figure 1. 
Shanghu lake ecological wetland has always a good effect on removal of the nitrogen and 
phosphorus in water body under different water temperatures (Table 5). There is an obvious purification 
effect when the surface runoff contained nitrogen and phosphorus into Shanghu lake ecological wetland, 
via contrast the water inlet indicators of TN, NH3-N, and TP with water outlet, the removal rates of TN, 
NH3-N, and TP are all beyond 50%.  
Tab. 5 The removal rates of nitrogen and phosphorus of Shanghu lake wetland under different water temperature 
Date of sample  Water  temperature [ ]ć  
Removal rate [%] 
NH3-N TN TP 
July 2008 29.7 89.3% 67.3% 50.0% 
November 2008 13.5 92.8% 74.9% 60.0% 
January 2009 5.0 94.1% 68.0% 78.9% 
The removal rate of NH3-N is the highest, which is always beyond 89.3% under any water 
temperature, with the maximum removal rate 94.1%. The removal rate of TN is closest under different 
temperatures, which is between 67.3% and 74.9%. And the removal rate of TP is the lowest, which is 
between 50.0% and 78.9%, with the minimum removal rate50.0%. 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
The variation tendency can be seen from Figure 1 as follows: (1) the removal rate of TN, NH3-N, 
and TP is different in the water body of Shanghu lake wetland, with the overall tendency of NH3-N > 
 
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2668   MA GuoSheng and CHEN Juan /  Procedia Environmental Sciences  10 ( 2011 )  2665 – 2670 
TN > TP; (2) when water temperature is reduced, the removal rate of NH3-N and TP in the water body of 
Shanghu lake wetland is in a rising trend, which means that when the water temperature is lower, the 
removal rate of NH3-N and TP in the water body of Shanghu lake wetland is higher, and the removal 
effects of NH3-N and TP in the water body of Shanghu lake wetland is better, especially TP; (3) the 
removal rate of NH3-N is always higher under any temperature comparing to TN and TP; (4) the removal 
rate of TP is related with water temperature to a certain extent, the moderate water temperature of a little 
more than 13ć is optimal for the TP removal. 
The relationship between the COD removal rate and the water temperatures. The results show 
that the COD value is reduced to varying extent through the purification of Shanghu lake wetland. The 
aquatic trees in Shanghu lake wetland have certain removal effects on COD (Table 6). 
Tab. 6 The COD content in Shanghu lake ecological wetland under different water temperature 
Sample 
points 
Jan-09 Feb-09 Mar-09 Apr-09 May-09 Jul-08 Nov-08 
w.t. COD w.t. COD w.t. COD w.t. COD w.t. COD w.t. COD w.t. COD
Water 
inlet 5.2 19 5.2 18 9.2 19 14.1 20 19.1 19 30.5 21 16.4 22 
Average 
of water 
body 
5.0 15 5.1 15 9.2 15 14.6 19 19.6 18 29.7 13 13.5 20 
Water 
outlet 5.2 11 5.0 10 9.4 11 14.3 16 19.5 14 30.2 13 13.8 18 
Note: w.t. is short for water temperature; the COD unit is mg.m-3; the water temperature unit is ć. 
The COD removal rate of Shanghu lake wetland under vary water temperature is statistically 
analyzed according to Table 6 (Table 7). 
Tab. 7 The removal rate of COD in Shanghu lake wetland under vary water temperature  
Projects Date and results Jan-09 Feb-09 Mar-09 Apr-09 May-09 Jul-08 Nov-08 
w.t. [ć]  5.0 5.1 9.2 14.6 19.6 29.7 13.5 
COD removal rate[%] 42.1 44.4 42.1 20.0 26.3 38.1 18.2 
Note: w.t. is short for water temperature; the date is sample date. 
The relationship of the removal rate of COD with water temperature is shown in Figure 2. 
The research results show the significant correlation between the water temperature of Shanghu lake 
wetland and the removal rate of COD, shown in Table 7 and Figure 2. 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
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2669 MA GuoSheng and CHEN Juan /  Procedia Environmental Sciences  10 ( 2011 )  2665 – 2670 
    As far as the date and the water temperature is concerned, the COD removal rate shows a declining 
tendency along with the water temperature declined from July to November (5~13.5ć). But the COD 
removal rate showed an ascending tendency along with the water temperature decline further from 
November to February for next year. The COD removal rate is at its maximum when the water 
temperature is at its minimum in February (5.1ć), but the rate is at its minimum when the water 
temperature is at its maximum in November (13.5ć). The COD removal rate shows an ascending 
tendency again along with the water temperature ascending from April to July (13.5~29.7ć).  
Discussion 
The Shanghu lake ecological wetland has improved the water quality of Shanghu lake effectively. The 
removal rates of TN, TP and AmmN are significance. The outlet water quality is continuously better than 
the National Level 2 or Level 3[2]. And the TN, TP and AmmN values in outlet water quality are lower 
than the treatment effect of wastewater plant in the same period. The aquatic woody plants in Shanghu 
lake ecological wetland had good purification effects on nitrogen and phosphorus in water body. And the 
Shanghu lake ecological wetland is a kind of economical and effective method. First report to removal 
effects on nitrogen and phosphorus of Shanghu lake wetland and woody plants wetland in China. 
The principle of wetland purifying is the synergetic and interaction of plants, soil and microorganisms in 
wetland [3]. Artificial wetland acts through the optional regrouping of physical, chemical and biological 
action in nature ecosystem, to treat the sewage. Many studies showed[4-6] that it has many merits of using 
the aquatic plants treatment system to control the water pollution, such as low investment, maintenance 
and operating costs, simple management, good treatment effects, improving and restoring 
eco-environment, recycling resource and energy, and harvesting economic plants, etc.. 
As a new type of technology, the ecological wetland has the results of beautifying environment and 
relieving greenhouse effect. It has a good performance in treating sewage and purifying eutrophicated 
water [7]. It has a bright future to use aquatic plants to purify sewage, especially for developing countries 
including China, with their awkward conditions of the environmental pollution and ecological 
deterioration, at the same time, without adequate funds to control pollution. The wetland purification 
gives an alternative treatment technique, and becomes a focus point for study on sewage treatment. The 
aquatic higher plants growing in polluted water body can improve water quality, relieve or eliminate 
pollution through the plants’ life activities to decompose, transpose or enrich the SS and contamination [8].  
The aquatic plants in ecological wetland are susceptible to seasons, both of the cold tolerance plants and 
thermopile plants need to be studied to adapt the varying season for different districts through the optimal 
community assembly of different plants so as to optimize sewage treatment effects. This problem needs 
further research. 
It also needs further research to resolve the difficult problem of the mosquitoes infesting in wetland if the 
aquatic plants grow overstocked or the plants residue salvaged untimely. 
References 
[1] G. Shao, R. Hai, J. Shenmang, C. Shaowei, L.Lifang and C. Xinhui: Effects of Pollution on the Aquatic Ecosystem in South 
China Botanical Garden, Ecologic Science, Vol.19, No.3 (2000), p. 37-40 
[2] State Environmental Protection Administration: Water and Wastewater Monitor Analysis Methods (the 4th edition) (China 
Environmental Science Press, Beijing 2002) 
[3] Y. Xiaozhong: Progress of Artificial Wetland to Nutrient Removal Research. Morden Agricultural Science and Technology, 
No.3 (2007), p. 128-129 
[4] Z. Zhiyong, W. Jianguo, Y. Linzhang and F. Minglei: Contribution of Plant Uptake to Nitrogen and Phosphorus Removal 
of Four Simulated Wastewater Treatment Systems, Soils, Vol.40, No.3 (2008), p. 412-418 
2670   MA GuoSheng and CHEN Juan /  Procedia Environmental Sciences  10 ( 2011 )  2665 – 2670 
[5] S. Gang and S. Lianxi: Ecological Engineering for Eutrophication Control in Lake. Chinese Journal of Applied Ecology, 
Vol.12, No.4 (2001), p.590̚592 
[6] W. Guoxiang, P. Peimin, Z. Shengzhao, L.Wanchun, H. Weiping, H. Chunhua: The Purification of Artificial Complex 
Ecosystem for Local Water in Taihu Lake. China Environmental Science, Vol.18, No.5 (1998), p.410~414 
[7] L. Xiaoli, W. Xao, Q. Yangyang: The Absorbency to Nitrogen and Phosphorus in Domestic Sewage in Wetland, Jiangsu 
Agricultural Science, No.4 (2008), p.296~298 
[8] H. Xiaoyuan, B. Jisheng, S. Zhiwen: Application and Advance of Aquatic Plants in Water Pollution Control, Journal of 
Qingdao Institute of Architecture and Engineering. Vol.26, No.16 (2005), p. 88~90 


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Removal Effects on Nitrogen, Phosphorus and COD in Water Body of Shanghu Lake Ecological Wetland in Taihu Lake Watershed

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