Investigation of Nitrate Removal from Zarjoub River Water of Rasht Using a Hybrid Wetland System

Document Type : Research Paper


1 Former Graduate Student in Irrigation and Drainage, Dept. of Water Engineering, College of Aburaihan, University of Tehran, Tehran, Iran

2 Assist. Prof., Dept. of Water Engineering, College of Aburaihan, University of Tehran, Tehran, Iran

3 Assoc. Prof., Dept. of Water Engineering, College of Aburaihan, University of Tehran, Tehran, Iran

4 Assoc. Prof., Dept. of Water Engineering, Faculty of Agricultural Science, University of Guilan, Rasht, Iran


With the influx of agricultural, industrial and hospital pollutants into surface and groundwater, human health and other living organisms are facing a serious threat. Zarjoub River is one of the most polluted rivers in the country, which passes through the center of Rasht and all kinds of dangerous pollutants such as nitrate, phosphate and dangerous heavy metals flow into it. Artificial wetlands are one of the low-cost and environmentally friendly wastewater treatment methods that have received a lot of attention today. In this study, the use of artificial wetlands in sequential using three different plant species of phragmites, lemna and vetiver with two different arrangements to remove nitrate in autumn of 2019 and summer of 2020 has been investigated. The results showed that the average percentage of nitrate reduction by two plant treatments was 73% and 68%, and for the control treatment it was 35%, which indicates the effect of plants in wetlands. Also, the result showed that the amount of nitrate reduction from the effluent was directly related to temperature changes and growth status of plants. The results showed that the use of hybrid wetlands can have a good removal efficiency for pollutants compared to their individual use, but the difference in plant arrangement in wetlands, although statistically significant at a probability level of 1%, had little effect on the nitrate removal process on effluent.


Arabnasrabadi, V. 2017. Improving the quality of urban wastewater using vetiver in artificial wetland system. M.Sc. Thesis, Isfahan University of Technology, Isfahan, Iran. (In Persian)
Ávila, C., Garfí, M. & García, J. 2013. Three-stage hybrid constructed wetland system for wastewater treatment and reuse in warm climate regions. Ecological Engineering, 61, 43-49.
Barakati, F., Alidadi, H., Najafpour, A. A. & Hasani, A. H. 2011. The use of vetiver instead of straw in artificial wetland system in municipal wastewater treatment. 14th National Conference on Environmental Health. Shahid Sadoughi University of medical Medical Sciences, Yazd, Iran. (In Persian)
Farid, M., Irshad, M., Fawad, M., Ali, Z., Eneji, A. E., Aurangzeb, N., et al. 2014. Effect of cyclic phytoremediation with different wetland plants on municipal wastewater. International Journal of Phytoremediation, 16, 572-581.
Ghodrati, A., Sobh, Z. S. & Dadashi, M. 2007. Investigation on industrial pollution of Zarjub river-Rasht city-Guilan province. Iranian Journal of Natural Resources, 60(1), 213-224. (In Persian)
Hammer, M. J. 1986. Water and Wastewater Technology. John Wiley, USA.
Kuschk, P., Wiessner, A., Kappelmeyer, U., Weissbrodt, E., Kästner, M. & Stottmeister, U. 2003. Annual cycle of nitrogen removal by a pilot-scale subsurface horizontal flow in a constructed wetland under moderate climate. Water Research, 37, 4236-4242.
Landrigan, P. J., Fuller, R., Acosta, N. J., Adeyi, O., Arnold, R., Baldé, A. B., et al. 2018. The lancet commission on pollution and health. The Lancet, 391, 462-512.
Mietto, A., Politeo, M., Breschigliaro, S. & Borin, M. 2015. Temperature influence on nitrogen removal in a hybrid constructed wetland system in Northern Italy. Ecological Engineering, 75, 291-302.
Mishra, S., Mohanty, M., Pradhan, C., Patra, H. K., Das, R. & Sahoo, S. 2013. Physico-chemical assessment of paper mill effluent and its heavy metal remediation using aquatic macrophytes-a case study at JK Paper mill, Rayagada, India. Environmental Monitoring and Assessment, 185, 4347-4359.
Moazed, H., Soltani, A., Zeynalzadeh, K. & Karimi, G. 2008. Wetland application for municipal and industrial waste water treatment. Proceedings of the 1st Symposium of the Sound Able Development Related to the Water Scarce. Tehran, Iran. (In Persian)
Salehzadeh, M. & Rezaie, H. 2017. Performance removal nitrate and phosphate from treated municipal wastewater using phragmites australis and typha latifolia aquatic plants. Journal of Civil and Environmental Engineering, 47, 59-67.
Schweitzer, L. & Noblet, J. 2018. Water Contamination and Pollution in Török, B. & Dransfield, T. Green Chemistry. Elsevier, USA.
Senzia, M., Mashauri, D. A. & Mayo, A. W. 2003. Suitability of constructed wetlands and waste stabilisation ponds in wastewater treatment: nitrogen transformation and removal. Physics and Chemistry of the Earth, Parts A/B/C, 28, 1117-1124.
Vymazal, J. 2011. Constructed wetlands for wastewater treatment: five decades of experience. Environmental Science and Technology, 45, 61-69.
Walaszek, M., Lenormand, E., Bois, P., Laurent, J. & Wanko, A. 2017. Urban stormwater constructed wetland: micropollutants removal linked to rain events characteristics and accumulation. Chemical Engineering Journal, 359, 1065-1074.
Zhao, X., Moates, G., Wellner, N., Collins, S., Coleman, M. & Waldron, K. 2014. Chemical characterisation and analysis of the cell wall polysaccharides of duckweed (Lemna minor). Carbohydrate Polymers, 111, 410-418.