1-D Transport Behaviour of Emerging Contaminants in the Unidirectional Flowing Surface Waters of the Msimbazi River

  • Hossein Miraji Chemistry Department, College of Natural and Mathematical Sciences, University of Dodoma, P. O. Box 338, Dodoma, Tanzania
  • Eunice Mureithi Mathematics Department, College of Natural and Applied Sciences, University of Dar es Salaam, P. O. Box 35062, Dar es Salaam, Tanzania
  • Othman C Othman Chemistry Department, College of Natural and Applied Sciences, University of Dar es Salaam, P. O. Box 35061, Dar es Salaam, Tanzania
  • Faustin Ngassapa Chemistry Department, College of Natural and Applied Sciences, University of Dar es Salaam, P. O. Box 35061, Dar es Salaam, Tanzania
Keywords: Modelling emerging contaminants; Advection-Dispersion Equation; Contaminants transport; First-type inlet condition; Concentration gradient

Abstract

The primary objectives of this investigation of environmental pollution were to assess spatio-temporal concentrations and predictions of transport behaviour of pollutants in aqueous media. In order to attain these goals for the Msimbazi river, the analytical and numerical solutions to the 1-D advection-dispersion equation (ADE) implemented the first-type inlet condition. The MATLAB software was used to solve the analytical equation resulting from the ADE equation. The solution to the ADE model enabled effective prediction of contaminants’spatial distribution within a distance of 200 m from a point source in the direction of flowing water. Among the first and third-types inlet conditions, the first-type had the best exponential concentration prediction with descending concentration gradients between –100 ng/L.m and –0.4 ng/L.m, while beyond it the concentration gradient was merely constant. These findings are the first of this type in our region to the best of our knowledge, and hence a milestone for understanding the transport behaviour of emerging contaminants, and enable estimation of probable pollution-free zones. This study gave results that can form a basis for analytical and public interventions.

Keywords: Modelling emerging contaminants; Advection-Dispersion Equation; Contaminants transport; First-type inlet condition; Concentration gradient

Published
2020-05-28
Section
Articles

Journal Identifiers


eISSN: 2507-7961
print ISSN: 0856-1761