Nitrogen and Phosphorus Removal from Nutrient Pollution by Cyperus Alternifolius and Eichhornia Crassipes in A Lab Scale Constructed Wetland



In recent years, aquaculture activities such as shrimp farming are sources of solid waste and liquid waste causing environmental pollution and make people living around shrimp farms worried. Phytoremediation technology with aquatic plants in wetlands is a potential solution to pollution from aquaculture activities. This study is to evaluate the potential and effectiveness of Cyperus alternifolius and Eichhornia crassipes in a lab-scaled constructed wetland in removing nutrients including nitrogen (N) and phosphorus (P) from wastewater of shrimp farms with 3-day, 10-day and 14-day experiments. The study’s result shows that the survival rates (SVR) of both studied aquatic plants is high (100%) during the 14-day experiment. By the end of the 14-day experiment, the concentrations of Ammonium-Nitrogen (NH4-N), Nitrate-Nitrogen (NO3-N) and Phosphate-Phosphorus (PO4-P) were significantly reduce by 89.3%, 94% and 89.3%, respectively.

Keywords: Nitrogen, phosphorus, Cyperus Alternifolius, Eichhornia Crassipes.

I. Introduction

Vietnam is the leading producer of shrimp in the world with a high production per year, there are many kind of shrimp as black tiger shrimp (Called Tôm Sú in Vietnam), Litopenaeus vannamei (Called Tôm thẻ chân trắng in Vietnam) and Giant freshwater Shrimp (Called Tôm càng xanh in Vietnam) in Vietnam, shrimp farming has rapidly expanded in recent years. Consequentially, the uneaten feed and excreted waste caused a number of water quality problems. The wastewater from shrimp farming is responsible for nutrient enrichment in receiving waters surrounding shrimp farm. Conventional wastewater treatment systems are costly to install and operate for treating the the wastewater from shrimp farming. And therefore, using bioremediation is an interesting alternative to solve this issue.

The principles of phytoremediation systems for cleaning up stormwater include: (a) identification and implementation of efficient aquatic plant systems; (b) uptake of dissolved nutrients including N, P, and metals by the growing plant; and (c) harvest and beneficial use of the plant biomass produced from the remediation system[1].

Macrophytes are commonly used in artificial wetland constructed for treatment of wastewater domestic sewage treatment in many countries. This plant is capable of removing organic matter, suspended solids and nutrients such as nitrogen and phosphorus from water. There are many species of Macrophytes as Cyperus Alternifolius and Eichhornia crassipes. First of all, Umbrella sedge or umbrella palm whose scientific name is Cyperus alternifolius, being rooted plants growing in wetlands. It is a multi-year-old and grow in humid soil and marshy areas. The plant has strong underground root, can be easily multiplied using seeds or pieces of the plant. Cyperus alternifolius’ advantage is that it eliminates nutrients of the wastewater [2]. Take an example, Cyperus alternifolius was assessed the treatment of municipal wastewater fromYazd city (center of Iran) by constructed wetland vegetated. Also Cyperus Alternifolius can grow well on any form of nitrogen and as they can develop a deep and dense root system [3]. This plant is selected as part of the wetland flora to reduce metal pollution in water resource, affected industrial activities[4]. Water hyacinth can grow well in water with concentration phosphate (P) levels above 20 ppm [5]. Water hyacinth (Eichhornia crassipes) have the optimal temperature for plant 's growth  from 200C to 300C, Water hyacinth produces new seedlings at higher temperatures and the reproductive mechanism of water hyacinth is not affected by plant size [6]. Water hyacinth can change its living state based on water characteristics or with low salinity [7]. Especially at low salinity of 0.2% will limit the ability of hyacinth development [8]. Water hyacinth can remove toxic heavy metals such as cadmium (Cd), lead (Pb), mercury (Hg) in a metal-containing solution without nutrients in the winter [9]. The values of the concentration factors in the roots tended to decrease, and the root concentration was higher at the leaf tips [10]. Results of [11] show that water hyacinth can reduce COD and BOD5 by 79% and 86%, respectively. Research [12] illustrates that water hyacinth is a good absorption of Cd and Zn. In Malaysia, water hyacinth is used to treat copper (Cu), cadmium (Cd), lead (Pb) and zinc (Zn) for four days. Water hyacinth can be considered as a treatment for heavy metal content in livestock wastewater, rather than pollutants in the water environment [13].

The present study seems part of management options in the near future for enhancing biological nutrient removal from wastewater of shrimp farming by natural and artificial wetland wetland technology. The objectives of this study were to evaluate the extent of nutrient (Ammonium-Nitrogen (NH4-N), Nitrate-Nitrogen (NO3-N) and Phoshphate-Phosphorus (PO4-P)) removal from this wastewater by a combine of as Cyperus Alternifolius and Eichhornia crassipes in A Lab Scale Constructed Wetland, compared to the control and QCVN08.

II. Materials and methods

1. Experimental set-up

Two lab scale constructed wetland was set up at the laboratory of Nguyen Tat Thanh University, each with a control and a treatment plot. Sample polluted water was selected for this study at the freshwater shrimp farmers, cultivating Giant freshwater Shrimp along the Saigon River, Ho Chi Minh City. Cyperus Alternifolius (Called Cây Thủy Túc in Vietnam) had fresh weight 163.66 ± 20.74g, length of plant 57.5 ± 0.71cm, length of root 28.00 ± 2.83 cm and Eichhornia Crassipes (Called Cây Lục Bình in Vietnam) had fresh weight 98.81±15.29g, length of root 20.25 ± 1.06cm, be grown in the experiment at start time, while no plant was maintained in the control plot. During experimental time, water samples were collected from start time, 3 dates, 7 dates, 10 dates and 14 dates for analyzing Nitrogen and Phosphorus as NO3-N, NH4-N, PO4-P. Specially, the control and the treatment plot were daily analyzed for water quality parameters, including temperature (0C), pH, Electrical conductivity (EC), total dissolved solids (TDS).

Figure 1: The lab scale constructed wetland applied in the experiment

The lab scale constructed wetland applied in the experiment

The wetland for treatment the aquacultural wastewater constructed by glass tank sizes as 1.000mm of length, 450mm of Wide, 600 mm of height (height submerged 500mm) with a circulation system. Volume of submerged part in glass fish tank around 98liters and the volume of the plastic tank with circulating pump around 80liters. This tank was divided into 3 main compartments with 2 compartments for growing Cyperus Alternifolius (3 layers from a bottom of 10kg of Lava stone, 10kg of large gravel and to top of 15kg of small gravel/ a compartment) and 1 compartment for growing Water hyacinth.

2. Samples Collection and Analysis

Samples were collected and stored with 2liters by plastic bottles in a refrigerator at 40oC with preservation as appropriate at the laboratory of Nguyen Tat Thanh University where appropriate equipment is available and functioning. Analyses activities conducted at this laboratories and prior to filtration, pH, EC, TDS, 0C of the water samples were determined using a combination of pH, Conductivity, total dissolved solids and temperature measurements (Mi805 Milwaukee Instruments,CO, USA). DO were determined by Milwaukee MW 600 Dissolved Oxygen Meter, CO, USA. HI83399-02 is a multiparameter photometer for measuring key water quality parameters as NO3-N, NH4-N, PO4-P in this study.

3. Analysis of Results

Results are presented as mean values or as mean ± SD, mean values of the experiment plot compared the control and the limit concentration in (QCVN 08: 2015 [14]).

III. Results and discussion

1. General water quality

Figure 2: (a) Temperature (b) Total Dissolved Solids (c) pH (d) Conductivity in water samples for all 14 dates of treatment

Conductivity in water samples for all 14 dates of treatment

Figure 2 (a-d) and Figure 3 illustrated the concentration of the analyzed in-situ parameters of this study with air temperature 270C at the laboratory of Nguyen Tat Thanh University. The parameters were reported as mean ± SD in this study. Water temperature, total suspended solids, EC, and pH in the waters of both control and experiment plots don’t significantly changed during treatment period. Figure 2a showed that water temperature in this research approximately fluctuated from 27.1 ± 0.0 0C to 29 ± 0.0 0C of control and 27.25 ± 0.0 0C to 29.1 ± 0.42 0C. In real condition, It means that this water temperature affects the high solubility of many chemical compounds and therefore cause the effect of several pollutants on aquatic life, for example, the optimum growth performance of fresh fish has a temperature range 20 - 300C [15 - 16].

The mean concentration of total dissolved solids in the water samples of control was 471.1mg/l and this ranged from 435 ± 7.07 to 493 ± 2.12mg/l and in the water samples of experiment was 482.7mg/l and this ranged from 440±0.00 to 506 ± 1.41mg/l. The trend of total dissolved solids in both plots is unchanged during the treatment in Figure 2b.

The pH (Figure 2c) average value recorded for the control was 7.92 and for the experiment was 8.08. The range concentration pH of control is from 7.54 ± 0.03 to 8.35 ± 0.07 and the range concentration pH of experiment is from 7.75 ± 0.07 to 8.80 ± 0.00. Specially, the highest concentrations of pH were observed 8.80 ± 0.00 in 10 dates in the experiment and then this trend is a same from 11 dates to 14 dates. This range was in the limit allowed by A1 in (QCVN 08: 2015) regulation 6 < pH < 8.5 for purposes of the domestic water supply and conservation of aquatic ecology[14]. It also accepted for the aquatic animal with pH 6-9 of El-Sheriff and El-Feky [17].

The illustration of conductivity was depicted in Figure 2d. The average conductivity values recorded for the control was 877.07µs/cm and this ranged from 843.5 ± 2.12 to 930 ± 0.00µs/cm and for the control was 895.83µs/cm and this ranged from 843 ± 38.00 to 950 ± 0.00µs/cm.

Vietnam’s average temperature has increased at a rate of 0.26 ± 0.100C per decade since results [18]. The high temperature in figure 2a leads the effect of the solubility of many chemical compounds and chemical reaction in water, making dissolved oxygen (DO) reduced and chemical oxygen demand (COD) increased. The average dissolved oxygen concentration (DO) recorded for the studied water samples of this study was 6.51mg/l of the control and 5.58mg/l of the experiment. The trend of DO in experiment was lower than the control plot, especially concentration of DO at 8dates, 9dates and10 dates was same with 5.45 ± 0.07mg/l, 5.45 ± 0.07mg/l and 5.45 ± 0.42mg/l respectively.

Figure 3: Concentration of DO (mg/l) in water samples for all 14 dates of treatmen 

Concentration of DO (mg/l) in water samples for all 14 dates of treatmen

2. N and P concentration reduction

Changes of inorganic N (NH4-N plus NO3-N), PO4-P concentrations in water for the period from 16/8/2019 to 16/8/2019 are shown in Figure 4, 5.

Figure 4: (a) NH4-N (b) NO3-N in water samples for all 14 dates of treatment

NH4-N (b) NO3-N in water samples for all 14 dates of treatment

Figure 5: PO4-P in water samples for all 14dates of treatment

PO4-P in water samples for all 14dates of treatment

The concentration of Ammonium-Nitrogen (NH4-N) in the water samples of this study was illustrated in Figure 4a. Volatilization happened in the inorganic forms as nitrate (NO3), nitrite (NO2), ammonia (NH3), and ammonium (NH4). The mean concentration NH4-N of the control and the treatment was 1.45 ± 00mg/l at start time. Figure 4a showed that concentration NH4-N of the experiment was lower than the control during the treatment. The final treatment at 14 dates recorded that the concentration NH4-N of control was 0.295 ± 0.01mg/l and the concentration NH4-N of experiment was 0.155 ± 0.01mg/l.

Plants or microbes uptake and oxidization of ammonia to nitrate in the nitrification process, it seems the main pathways of ammonia removal from the wetland. Nitrate and nitrite in this wetland may be removed by plant uptake ordenitrification [15]. Once nitrogen has been denitrified, it can be released in the atmosphere as nitrous oxide (N2O) or dinitrogen gas (N2) during the treatment time. Denitrification can bring about the removal of nitrogen from the waste water and is the most important removal pathway for nitrogen in natural or artificial wetlands.

The NO3-N concentration in the water samples of this study was shown in figure 4b. The figure 4b showed that concentration NO3-N of the experiment was lower than the control during the treatment. At start time of this study was 7.15 ± 0.21mg/l of NO3-N, and the water quality was higher than the limit allowed by A2 in (QCVN 08: 2015) regulation NO3-N < 5mg/l for water supply and conservation of aquatic ecology and if surface waters often contains NO3-N less than 1mg/l of nitrate NO3-N [19], that's not a good thing for aquatic life. Especially, Figure 4 a&b illustrated that concentration of Ammonium-Nitrogen of control and the experiment plot was 2.035 ± 0.02mg/l and 1.83 ± 0.03mg/l at 3 dates respectively. At this date the concentration of Nitrate-Nitrogen was 1.6 ± 0.42mg/l of control and 0.35 ± 0.07mg/l of the experiment plot. To be continued, all Ammonium-Nitrogen significantly reduced at 7 dates, but there was the high increase of Nitrate-Nitrogen. The term ammonia (NH4-N) includes non-ionized (NH3) and ionized (NH4+). The NH4-N levels for the experiment dates pass a limit allowed by A1, A2 in (QCVN 08: 2015) regulation NH4-N < 0.3mg/l for conservation of aquatic ecology and B1, B2 in (QCVN 08: 2015) < 0.9mg/l for low quality water requirements & transportation of navigable waterway. This Lab Scale Constructed Wetland can treat Ammonium in the aquaculture wastewater thoroughly before discharging it into water resources.

The Phosphates-phosphorus (PO4-P) of experiment recorded mean was lower than the concentration of PO4-P in the control plot during 14 dates (Figure 5). At the end of 14dates, the the lowest concentration of PO4-P was 0.18 ± 0.03mg/l of the experiment plot, it seem very lower than 0.78 ± 0.03mg/l of the control plot. Almost PO4-P concentration were in this experiment affected the a conservation of aquatic plants and animalsin because (QCVN 08 2015) regulation PO4-P from PO4-P < 0.1 mg/l of A1 to PO4-P < 0.5 mg/l of B2 [14]. This Lab Scale Constructed Wetland can significantly reduce Phosphates before discharging it into water resources.

IV. Conclusions

This study showed that two aquatic macrophytes as Cyperus Alternifolius and Eichhornia Crassipes could be used in reducing the N and P levels of nutrient enriched waters of wastewater from shrimp farms. So, this Lab Scale Constructed Wetland with both aquatic plants could be effectively used in reducing the concentration of Ammonium-Nitrogen (NH4-N), Nitrate-Nitrogen (NO3-N), Phoshphate-Phosphorus (PO4-P), if effectiveness is proved that the concentration of experiment plot compared to the concentration of the control plot in 3 dates, 7 dates, 10 dates and 14 dates or even at start time of this study.


This research is funded by NTTU foundation for science and technology development under grant number 20190144.


1. Q. Lu, Z. L. He, and D. A. Graetz, “Phytoremediation to remove nutrients and improve eutrophic stormwaters using water lettuce ( Pistia stratiotes L .),” Env. Sci Pollut Res, pp. 84 - 96, 2010.

2. A. Ebrahimi et al., “Efficiency of Constructed Wetland Vegetated with Cyperus alternifolius Applied for Municipal Wastewater Treatment,” Environ. Public Heal., pp. 1 - 6, 2013.

3. A. Jampeetong, H. Brix, and S. Kantawanichkul, “Effects of inorganic nitrogen forms on growth , morphology , nitrogen uptake capacity and nutrient allocation of four tropical aquatic macrophytes ( Salvinia cucullata , Ipomoea aquatica , Cyperus involucratus and Vetiveria zizanioides ),” Aquat. Bot., vol. 97, no. 1, pp. 10 - 16, 2012.

4. A. Guittonny-philippe, V. Masotti, P. Hưhener, J. Boudenne, J. Viglione, and I. Laffont-schwob, “Constructed wetlands to reduce metal pollution from industrial catchments in aquatic Mediterranean ecosystems: A review to overcome obstacles and suggest potential solutions,” Environ. Int., vol. 64, pp. 1 - 16, 2014.

5. Yoko Oki. Misako ITO and Kunikazu UEKI, “Studies on the Growth and Reproduction of Waterhyacinth, Eichhornia crassipes (Mart) Solms,” 雑G 草 研 究? (weed Res., vol. 23, 1978.

6. Yoko OKI and K. R Reddy, “Variation in Productive Characters of Water Hyacinth in Florida,” Weed Res. Japan, vol. 34, pp. 107 - 116, 1989.

7. S. Muramoto I. Aoyama and Y. Oki, “Effect of salinity on the concentration of some elements in water hyacinth (Eichhornia crassipes) at critical levels,” J. ENVIRON. SCI. Heal., pp. 205 - 215, 1991.

8. A. T. Ellis, “Invasive species profile water hyacinth, Eichhornia crassipes,” Univ. Washingt., p. 7, 2011.

9. S. Muramoto and Y. Oki, “Removal of some heavy metals from polluted water by water hyacinth (Eichhornia crassipes),” Bull. Environ. Contam. Toxicol., vol. 30, no. 1, pp. 170 - 177, 1983.

10. S.Muramoto and Y. Oki, “Influence of anionic surface-active agents on the uptake of heavy metals by water hyacinth (Eichhornia crassipes),” Bull. Environ. Contam. Toxicol., vol. 33, no. 1, pp. 444 - 450, 1984.

11. A. Valipour, V. K. Raman, and Y. H. Ahn, “Effectiveness of domestic wastewater treatment using a Bio-hedge water hyacinth wetland system,” Water (Switzerland), vol. 7, no. 1, pp. 329 - 347, 2015.

12. X. Lu, M. Kruatrachue, P. Pokethitiyook, and K. Homyok, “Removal of Cadmium and Zinc by Water Hyacinth , Eichhornia crassipes,” Sci. Asia, vol. 30, no. June 2015, pp. 93 - 103, 2004.

13. Y. S. Yen, “Heavy metal removal in animal wastewater using water hyacinth (Eichhornia crassipes),” Univ. Malaysia Sarawak J., pp. 1 - 24, 2007.

14. QCVN 08:, National Technical Regulation On Surface Water Quality (Quy Chuẩn Kỹ Thuật Quốc Gia Về Chất Lượng Nước Mặt ). 2015.

15. Catalina Ciortan Mirea, V. Cristea, Iulia Rodica Grecu, and Lorena Dediu, Influence of Different Water Temperature on Intensive Growth Performance of Nile Tilapia ( Oreochromis Niloticus , Linnaeus , 1758 ) in a Recirculating Aquaculture System, vol. 60. University of Agricultural Sciences and Veterinary Medicine Iasi, 2013.

16. Luong Quang Tuong and Nguyen Phi Nam, “Different Growth Performance - Tilapia (Oreochromis Niloticus) In using Two Different Types of Feed at Hoa My Reservoir, Thua Thien Hue Province, Vietnam,” Khoa Học Kỹ Thuật Thủy Lợi Và Môi Trường ISSN 1859-3941 (Journal Water Resour. Environ. Eng., vol. 56, pp. 9 - 15, 2017.

17. M. S. El-Sheriff and A. M. I. El-Feky, Performance of Nile Tilapia ( Oreochromis niloticus ) Fingerlings . I . Effect of pH. International journal of Agriculture and Biology, 2009.

18. Nguyen Dang Quang, James Renwick, and James Mcgregor, Variations of surface temperature and rainfall in Vietnam from 1971 to 2010, vol. 34, no. 1. International Journal of Climatology, 2014.

19. J. Adeola Alex Adesuyi, Valerie Chinedu Nnodu, Kelechi Longinus Njoku, Anuoluwapo, Nitrate and Phosphate Pollution in Surface Water of Nwaja Creek, Port Harcourt, Niger Delta, Nigeria. International Journal of Geology, Agriculture and Environmental Sciences, 2015.








Khoa Kỹ thuật Thực phẩm và Môi trường, Đại học Nguyễn Tất Thành


Trong những năm gần đây, các hoạt động trong nuôi trồng thủy sản như nuôi tôm đã phát sinh các nguồn chất thải rắn, chất thải lỏng gây ô nhiễm môi trường. Sự việc này đã khiến nhiều người dân trên địa bàn xung quanh trang trại nuôi tôm lo lắng. Công nghệ xử lý ô nhiễm bằng thực vật thủy sinh trong mô hình đất ngập nước được xem là một giải pháp tiềm năng trong việc khắc phục vấn đề ô nhiễm nêu trên. Mục tiêu của nghiên cứu này là đánh giá tiềm năng và hiệu quả xử lý của Thủy trúc "Cyperus Alternifolius" và Bèo tây "Eichhornia crassipes" trong mô hình đất ngập nước ở quy mô phòng thí nghiệm để loại bỏ các chất dinh dưỡng trong nước như  nitơ (N) và phốt pho (P) đối với nước thải nuôi tôm sau 3 ngày, 7 ngày, 10 ngày và 14 ngày. Kết quả đạt được, công nghệ xử lý ô nhiễm bằng thực vật cho kết quả tốt, với tỷ lệ sống sót (SVR) của cả 2 loài thực vật là cao, với 100% sau 14 ngày thí nghiệm. Mô hình đất ngập nước đã đưa hiệu quả xử lý cao khi nồng độ tại ngày thí nghiệm cuối cùng so với nồng độ tại thời điểm bắt đầu. Chi tiết như sau: nồng độ Ammonium-Nitrogen (NH4-N) giảm 89,3%, Nitrate-Nitrogen (NO3-N) giảm 94% và Phoshphate-Phospho (PO4-P) giảm được 89,3%.

Từ khóa: Nitrogen, phosphorus, Cyperus Alternifolius, Eichhornia Crassipes.