Journal of Water Resource and Protection, 2014, 6, 722-730 Published Online May 2014 in SciRes. http://www.scirp.org/journal/jwarp http://dx.doi.org/10.4236/jwarp.2014.67069 How to cite this paper: Agu, C.C., et al. (2014) Evaluation of the Level and Impact of Selected Physiochemical Parameters of Fertilizer Effluent on Obinna River, Adani, Enugu State, Nigeria. Journal of Water Resource and Protection, 6, 722-730. http://dx.doi.org/10.4236/jwarp.2014.67069 Evaluation of the Level and Impact of Selected Physiochemical Parameters of Fertilizer Effluent on Obinna River, Adani, Enugu State, Nigeria Chizoba Chinelo Agu 1* , Matthew Chukwudi Menkiti 2 , Bernard Ibezim Okolo 3 , Patrick Chukwudi Nnaji 3 1 Center for Environmental Management and Control (CEMAC), University of Nigeria, Enugu, Nigeria 2 Department of Chemical Engineering, Nnamdi Azikiwe University, Awka, Nigeria 3 Department of Chemical Engineering, Michael Okpara University of Agriculture, Umudike, Nigeria Email: * aguzoba@yahoo.com Received 1 March 2014; revised 2 April 2014; accepted 29 April 2014 Copyright © 2014 by authors and Scientific Research Publishing Inc. This work is licensed under the Creative Commons Attribution International License (CC BY). http://creativecommons.org/licenses/by/4.0/ Abstract This work quantitatively evaluates the level and impact of selected physiochemical properties of fertilizer effluent on the Obinna River of Adani, Enugu State, Nigeria. The fertilizer effluent origi- nated from surrounding farms and flushed into the Obinna River. Water samples were collected from designated points along the river and analysed for physical, chemical and biological proper- ties using standard methods of APHA. Impact of selected key parameters such as nitrate, phos- phate, manganese, dissolved oxygen, biochemical oxygen demand and heavy metals (lead, iron and manganese), was studied. The results of the parameters were compared with the World Health Organisation (WHO) permissible standard for freshwater. Measured concentrations of phosphate (5.00, 7.21, 3.92 mg/L), manganese (1.53, 1.18, 1.47 mg/L) and lead (18.9, 21.7, 39.7 ppm) were found to be above the WHO standard while nitrate (0.04, 0.03, 0.03 mg/L) and iron (0.001, 0.001, 0.1 mg/L) were within the standard. The mean concentrations of heavy metals in- creased in the following order: Fe (0.034) < Mn (1.4) < Pb (26.8) from upstream S1 to downstream S 3 , with manganese and lead being above WHO standard. The results showed a level of significance for the chi-square distribution and correlation coefficients while the analysis of variance (ANOVA) results was conflicting. It could be inferred that the impact of the selected parameters contributed to the pollution of Obinna River. Keywords Physiochemical, Heavy Metals, WHO, Pollution, Obinna River * Corresponding author.