CWEEE  Vol.3 No.4 , October 2014
Application of Water Quality Model QUAL2K to Model the Dispersion of Pollutants in River Ndarugu, Kenya
ABSTRACT

Ndarugu River, Kenya, during its course through the different agricultural and industrial areas of Gatundu, Gachororo and Juja farms, receives untreated industrial, domestic and agricultural waste of point source discharges from coffee and tea factories. During wet season the water is also polluted by non-point (diffuse) sources created by runoff carrying soil, fertilizer and pesticide residues from the catchment area. This study involved the calibration of water quality model QUAL2K to predict the water quality of this segment of the river. The model was calibrated and validated for flow discharge (Q), temperature (T&deg), flow velocity (V), biochemical oxygen demand (BOD5), dissolved oxygen (DO) and nitrate (NO3-N), using data collected and analyzed during field and laboratory measurements done in July and November-December 2013. The model was then used in simulation and its performance was evaluated using statistical criteria based on correlation coefficient (R2) and standard errors (SE) between the observed and simulated data. The model reflected the field data quite well with minor exceptions. In spite of these minor differences between the measured and simulated data set at some points, the calibration and validation results are acceptable especially for developing countries where the financial resources for frequent monitoring works and higher accuracy data analysis are very limited. The water is being polluted by the human activities in the catchment. There is need for proper control of wastewater by various techniques, and preliminary treatment of waste discharges prior to effluent disposal. Management of the watershed is necessary so as to protect the river from the adverse impacts of agricultural activities and save it from further deterioration.


Cite this paper
Hadgu, L. , Nyadawa, M. , Mwangi, J. , Kibetu, P. and Mehari, B. (2014) Application of Water Quality Model QUAL2K to Model the Dispersion of Pollutants in River Ndarugu, Kenya. Computational Water, Energy, and Environmental Engineering, 3, 162-169. doi: 10.4236/cweee.2014.34017.
References
[1]   Nakhaei, N. and Shahidi, A.E. (2010) Waste Water Discharge Impact Modeling with QUAL2K, Case Study: The Zayandeh-Rood River. International Environmental Modelling and Software Society (IEMSS), Ottawa.

[2]   Brown, L.C. and Barnwell, T.O. (1987) The Enhanced Stream Water Quality Models QUAL2E and QUAL2E-UNCAS (EPA/600/3-87-007). US Environmental Protection Agency, Athens.

[3]   Park, S.S. and Lee, Y.S. (2002) A Water Quality Modeling Study of the Nakdong River Korea. Ecological Modeling, 152, 65-75.
http://dx.doi.org/10.1016/S0304-3800(01)00489-6

[4]   Chapra, S.C., Pelletier, G.J. and Tao, H. (2008) QUAL2K: A Modeling Framework for Simulating River and Stream Water Quality, Version 2.11. USA: Documentation and User’s Manual. Civil and Environmental Engineering Department, Tufts University, Medford.

[5]   Kalburgi, P.B., Shivayogimath, C.B. and Purandara, B.K. (2010) Application of QUAL2K for Water Quality Modeling of River Ghataprabha (India). Journal of Environmental Science and Engineering, 4, 6-11.

[6]   Kanne, P.R., Lee, S., Lee, Y.S., Kanel, S.R. and Pelletier, G.J. (2007) Application of Automated QUAL2Kw for Water Quality Modeling and Management in the Bagmati River. Elsevier, Amsterdam, 503-517.
http://www.sciencedirect.com/

[7]   Zhang, R.B., Qian, X., Yuan, X.C., Ye, R., Xia, B.S. and Wang, Y.L. (2012) Simulation of Water Environmental Capacity and Pollution Load Reduction Using QUAL2K for Water Environmental Management. International Journal of Environmental Research and Public Health, 9, 4504-4521. http://dx.doi.org/10.3390/ijerph9124504

 
 
Top