Water Quality Modelling of Major Drains of Patna, India by using Bioremediation to Attain Sustainable Goals for River Ganga

Abstract

Since 1990s, the major water polluting drains discharging to the River Ganga at Patna, Bihar, India have polluted and infected the river Ganga significantly. The possible addition of bioremediation and aeration at different reaches of wastewater drains is essential to attain sustainable goals (ASG) at the confluence of river Ganga with wastewater drains.

In order to evaluate the effects of possible bioremediation and aeration measures on DO, BOD, COD, Faecal coliform and total Coliform, a simple first-order faecal coliform decay model and chemical mass balance models have been added to the continuous-simulation flow-water quality model based on St. Vanant Equation. A modified concept of model parameter estimation based on natural drain discharge data has been used and applied to the model. The first order decay rate k was estimated for every reach of the of the major Rajapur drain. A total of 144 samples have been collected during April-June during the year 2022 at 15 days interval from Rajapur drain (a) at initial condition of wastewater without any prior treatment, (b) after use of aerators for reaeration, (c) after use of a biological product for bioremediation, and (d) after use of biological product for bioremediation and aerators for reaeration.