Global Journal of Engineering and Technology Advances, 2020, 05(02), 038–046 Global Journal of Engineering and Technology Advances Cross Ref DOI: 10.30574/gjeta Journal homepage: http://www.gjeta.com  Corresponding author: Baridakara Nwidadah Master student, Department of Environmental Engineering and Technology, University of Port Harcourt. Copyright © 2020 Author(s) retain the copyright of this article. This article is published under the terms of the Creative Commons Attribution Liscense 4.0. (R ESEARCH A RTICLE ) Curve fitting the hydrodynamic and dispersion characteristics of pollutant released in an inland water system Baridakara Nwidadah 1, * and Olalekan Michael Adeloye 2 1 Master student, Department of Environmental Engineering and Technology, University of Port Harcourt. 2 Doctoral student, Department of Chemical/Petrochemical Engineering, Rivers State University, Port Harcourt. Publication history: Received on 12 November 2020; revised on 20 November 2020; accepted on 21 November 2020 Article DOI: https://doi.org/10.30574/gjeta.2020.5.2.0098 Abstract The research study was performed by estimating the longitudinal dispersion coefficient for Dor Nwezor section of Bodo- Bonny River and conducting a tracer experiment using the constant distance variable time method. Eleven empirical models for the prediction of longitudinal dispersion coefficients were considered and analyzed using the hydraulic and geometric parameters of the river. The empirical and experimental results were analysed and compared statistically with Deng et al model yielded the most reliable method of predicting the longitudinal coefficient of dispersion of Dor Nwezor section of Bodo-Bonny River with the least root mean square value of 0.1221, mean absolute value of 0.0617 close to zero and discrepancy ratio of -0.2303 that falls within the accepted accuracy range of -0.3 to 0.3. Keywords: Bodo-Bonny River; Dispersion Coefficient; Discrepancy Ratio; Mean Absolute Error; Root Mean Square. 1. Introduction The chances that a pollutant, sewage, industrial waste, run offs, chemical wash offs into a water bodies (rivers, lakes, streams, ocean) is of a major disturbance to those diverting and consuming water from such sources. A method of rapidly estimating travel time or dispersion rate of pollutants is needed for pollution control or force warning system on streams where data are limited. As greater demands are placed on streams by communities, the evaluation of significant parameters of self-purification, such as de-oxygenation and re-aeration properties, becomes increasingly necessary. Therefore, the ability to simulate potential pollution buildup in streams, lakes, estuaries, and the likes becomes increasingly important[1] Thus, dispersion is associated with both longitudinal, and axial transportation of material due to its molecular dissemination, turbulent eddies, and velocity variance[2] Longitudinal dispersion is the action by which water flowing in a stream or river spreads out to dilute mass of pollutants, Rather than moving it downstream as a slug, such a mass is dispersed in the direction of flow of the river at different speeds[3] Hydrodynamics is simply the study of a fluid in motion [4] Hydrodynamic properties of a fluid in motion include flow rate, velocity, temperature, pressure, density, all as a function of space and time [5] Hydrodynamics and pollutant emission dispersion characteristics of water bodies are important variables in the planning, management of river basin, and in hydraulic modeling with major consideration to aquatic ecosystems protection and different water usages [6]. 1.1. Study Area Ogoniland in South-South region is divided administratively into four Local Government Areas (Eleme, Gokana, Khana, and Tai), made up of six kingdoms (babbe, Eleme, Gokana, ken-khana, nyo-khana, and Tai) covering some 1,000 km 2 in the south-east of the Niger Delta basin. It has a population of close to 832,000 according to the 2006 National Census with a 2.5% growth rate between 2007-2010, it was recorded as 914,899 consisting mainly of the Ogoni people and