Synthesis and characterization of graphitic carbon nitride/kaolin nanocomposite for photocatalytic removal of nitrate from aqueous solutions

Subject Areas :

Elham Asadi ¹ , Mohammad Hadi Ghasemi ² , Parviz Ahmadi ³ , Nahid Monajjemi ⁴ , Maryam Afsharpour ⁵ , Majid Baghdadi ⁶

1 - Ph.D student in Applied Chemistry Research Group, Academic Center for Education, Culture and Research (ACECRTehran, Iran
2 - Assistant Prof. in Applied Chemistry Research Group, Academic Center for Education, Culture and Research (ACECR), Tehran, Iran.
3 - Instructor in Applied Chemistry Research Group, Academic Center for Education, Culture and Research (ACECR), Tehran, Iran.
4 - Ph.D student in Chemistry and Chemical Engineering Research Center of Iran (CCERCI), Tehran, Iran
5 - Assistant Prof. in Chemistry and Chemical Engineering Research Center of Iran (CCERCI), Tehran, Iran.
6 - Associate Prof. in School of Environment, College of Engineering, University of Tehran, Tehran, Iran

Received: 2021-06-20 Accepted : 2021-06-20 Published : 2021-05-22

Keywords: Water Treatment, Kaolinite, Photocatalytic nanocomposite, Graphitic Carbon Nitride, Nitrate Reduction,

Abstract :

Nitrate ion in water causes human poisoning and is very dangerous. Photocatalytic removal of nitrate from water and conversion to nitrogen gas is of great importance. In this study, heterogeneous nanocomposite g-C3N4/kaolinite, due to its natural kaolin substrate has been considered to nitrate reduction in the presence of UV light. The results of nanocomposite photocatalyst analysis using FTIR, SEM, EDS, and XRD instruments have clearly shown that the surface of the kaolin is covered by graphitic carbon nitride. In this work, the nitrate aqueous solution containing nitrate ion (50 ppm) was subjected to a photocatalytic reaction. Nitrate removal results showed the highest rate of nitrate degradation in the first 60 minutes compared with graphitic carbon nitride and kaolin individually. With the removal efficiency of 93.15% using the above method, the initial concentration of 50 ppm reaches 3.5 ppm, nitrate ion, which is below the permissible level of nitrate according to the World Health Organization standard. Therefore, the use of nanocomposite is a convenient choice to remove nitrate from water due to the simplicity of the preparation and commercial access to the raw materials required for synthesis, as well as high efficiency and selectivity to N2 in nitrate degradation and non-contamination of effluent.

References:

[1] Afzal, B.M.; J. Midwifery Womens Health. 51, 12-18, 2006.

[2] Spalding, R.F.; Exner, M.E., J. Environ. Qual. 22, 392-402, 1993.

[3] Rupert, M.G.; J. Environ. Qual. 37, 1988–2004, 2008.

[4] Schlesinger, W.H.; Proceedings of the National Academy of Sciences 106, 203-208, 2009.

[5] Heidariyeh, A.; Ghobakhloo, S.; Abdolshahi, A.; Marvdashti, L. M.; Zeinali, M. K.; Ashhad, S.; Koomesh. 21, 381-386, 2019.

[6] Liu, J.; Liu, Y.; Liu, N.; Han, Y.; Zhang, X.; Huang, H.; Lifshitz, Y.; Lee, S.T.; Zhong, J.; Kang, Z.; Science 347, 970-974, 2015.

[7] Uyguner-Demirel, C.S.; Bekbolet, M.; Chemosphere 84, 1009-1031, 2011.

[8] Zhang, C.; Li, Y.; Shuai, D.; Shen, Y.; Xiong, W.; Wang, L.; Chemosphere 214, 462-479, 2019.

[9] Jiang, L.; Yuan, X.; Pan, Y.; Liang, J.; Zeng, G.; Wu, Z.; Wang, H.; Appl. Catal. B-Environ. 217, 388-406, 2017.

[10] Inagaki, M.; Tsumura, T.; Kinumoto, T.; Toyoda, M.; Carbon 141, 580-607, 2019.

[11] Kloprogge, J. T.; Cham. 41-96, 2019.

[12] Sun, Z.; Li, C.; Du, X.; Zheng, S.; Wang, G.; J. Colloid Interface Sci. 511, 268-276, 2018.

[13] Sholl, D.S.; Steckel, J.A.; “Density functional theory: a practical introduction” John Wiley & Sons, Canada, 2011.

[14] Li, Y.; Li, S.G.; Wang, J.; Li, Y.; Ma, C.H.; Zhang, L.; Russ. J. Phys. Chem. A. 88, 2471–2475, 2014.

[15] Zhang, Q.; Yan, Z.; Ouyang, J.; Zhang, Y.; Yang, H.; Chen, D.; Appl. Clay Sci. 157, 283-290, 2018.

[16] Wang, A.; Wang, C.; Fu, L.; Wong-Ng, W.; Lan, Y.; Nanomicro Lett. 9(4), 1-21, 2017.

[17] Sun, D.; Yang, W.; Zhou, L.; Sun, W.; Li, Q.; Shang, J.K.; Appl. Catal. B Environ. 182, 85–93, 2016.