Development of Refined BOD and DO Models for Highly Polluted Kali River in India

Abstract

Most commonly used river water quality models for biochemical oxygen demand (BOD) and dissolved oxygen (DO) simulations are mainly based on advection, decay, settling, and loading functions. Using these concepts, refined river water quality models for BOD and DO simulations are developed in the present work considering a large number of physically based parameters and input variables. The refined models developed can be transformed to some of the commonly used river water quality models, if physically based parameters and input variables are omitted or removed. To test the applicability of the refined models developed and commonly used models, a total of 732 water quality and flow data sets are collected during March 1999–February 2000 from 22 sampling stations of the River Kali in India. River Kali is a highly polluted river in India and receives continuous inflow of untreated point source pollution from municipal and industrial wastes and nonpoint source pollution from agricultural areas. Newton–Raphson technique is used to optimize the model parameters during calibration and the performance of different models are evaluated using error estimation, viz. standard error and mean multiplicative error, and correlation statistics