Performance evaluation and numerical simulation of vertical subsurface flow constructed wetlands in wastewater treatment

Document Type : Research Paper

Authors

Department of Civil Engineering, National Institute of Technology Calicut, India

Abstract

Constructed wetlands are extensively employed to treat wastewater in many countries and are an eco-friendly and low-cost wastewater treatment technique. In this study, the performance of an intermittently operated vertical subsurface flow constructed wetland planted with Amaranthus dubius and the effect of adding oyster shells as a substrate layer in the wetland on its performance were investigated. Major quality parameters such as phosphates, ammonia nitrogen, nitrite nitrogen, nitrate nitrogen, Total Organic Carbon and COD in the effluent and influent were monitored and compared. The concentration of these quality parameters was determined by the colorimetric method in the laboratory using a UV-Visible spectrophotometer. The results indicated that the planted vertical subsurface flow constructed wetlands achieved efficient removal of ammonia nitrogen from the wastewater and were effective for nitrification. The addition of oyster shells in the substrate enhanced the total nitrogen removal from the wastewater. The ability of the HYDRUS CW2D model in simulating reactive transport through a vertical subsurface flow constructed wetland was also investigated. A good match between the measured and simulated parameters could be achieved after adjusting certain constructed wetland parameters in the HYDRUS CW2D model. Model validation was performed based on a quantitative statistic known as the ratio of root mean square error (RMSE) to the standard deviation of the observed data - . The value for ammonia nitrogen and nitrate nitrogen was less than 0.70, which is satisfactory.  

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References

[1] Kadlec, R. H., Wallace, S. (2008). Treatment Wetlands. CRC Press.
[2] Vymazal, J. (2010). Constructed wetlands for wastewater treatment. Water, 2(3), 530-549.
[3] Zhang, D. Q., Jinadasa, K. B. S. N., Gersberg, R. M., Liu, Y., Ng, W. J., Tan, S. K. (2014). Application of constructed wetlands for wastewater treatment in developing countries–a review of recent developments (2000–2013). Journal of environmental management, 141, 116-131.
[4] Eslamian, S. (2016). Urban water reuse handbook. Taylor and Francis.
[5] DuPoldt, C., Edwards, R., Garber, L., Isaacs, B., Lapp, J., Murphy, T., Rider, G., Sayers, M., Takita, C., Webster, H. (2000). A handbook of constructed wetlands. A guide to creating wetlands for: agricultural wastewater, domestic wastewater, coal mine drainage, stormwater,  BiblioGov.
[6] Reddy, K. R., DeBusk, T. A. (1987). State of the art utilization of Aquatic plants in water pollution control. Water science and technology, 19(10), 61–79.
 [7] Saeed, T., Sun, G. (2012). A review on nitrogen and organics removal mechanisms in subsurface flow constructed wetlands: Dependency on environmental parameters, operating conditions and supporting media. Journal of environmental management, 112, 429–448.
[8] Winter, K. J., Goetz, D. (2003). The impact of sewage composition on the soil clogging phenomena of vertical flow constructued wetlands. Water science and technology, 48(5), 9–14.
[9] Yam, R. S. W., Hsu, C. C., Chang, T.-J., Chang, W. L. (2013). A Preliminary investigation of wastewater treatment efficiency and economic cost of subsurface flow oyster-shell-bedded constructed wetland systems. Water, 5(3), 893–916.
[10] Brix, H. (1997). Do macrophytes play a role in constructed treatment wetlands? Water science and technology, 35(5), 11–17.
[11] Langergraber, G., Šimůnek, J. (2005). Modeling variably saturated water flow and multicomponent reactive transport in constructed wetlands. Vadose zone journal, 4(4), 924–938.
[12] García, J., Rousseau, D. P. L., Morató, J., Lesage, E., Matamoros, V., Bayona, J. M. (2010). Contaminant removal processes in subsurface-flow constructed wetlands: A review. Critical reviews in environmental science and technology, 40(7), 561–661.
[13] Tsihrintzis, V. A. (2017). The use of vertical flow constructed wetlands in wastewater treatment. Water resources management, 31(10), 3245–3270.
[14] Weber Jr, W. J., Morris, J. C. (1963). Kinetics of adsorption on carbon from solution. Journal of the sanitary engineering division, 89(2), 31-59.
[15] Šimůnek, J., Van Genuchten, M. T., Šejna, M. (2012). Hydrus: Model use, calibration, and validation. Transactions of the ASABE, 55(4), 1261–1274.
 [16] Langergraber, G., Šimůnek, J. (2005). Modeling variably saturated water flow and multicomponent reactive transport in constructed wetlands. Vadose zone journal, 4(4), 924–938.
[17] Šimůnek, J., Van Genuchten, M. T., Šejna, M. (2016). Recent developments and applications of the HYDRUS computer software packages. Vadose zone journal, 15(7), vzj2016-04.
[18] Shelef, O., Gross, A., Rachmilevitch, S. (2013). Role of plants in a constructed Wetland: Current and new perspectives. Water (Switzerland), 5(2), 405–419.
[19] Hoffmann, H., Platzer, C., Winker, M., & von Muench, E. (2011). Technology review of constructed wetlands Subsurface flow constructed wetlands for greywater and domestic wastewater treatment. Deutsche Gesellschaft für Internationale Zusammenarbeit (GIZ) GmbH, Eschborn, Germany.
 
 
 
Advances in Environmental Technology
Volume 7, Issue 1
January 2021
Pages 37-46

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History

  • Receive Date: 28 January 2021
  • Revise Date: 12 September 2021
  • Accept Date: 13 September 2021

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