Numerical and Physical Modeling of Bioremediation of Contaminants in Groundwater

Abstract

Groundwater is one of the major sources of water that humanity gets the supply of water for domestic use, industry and agriculture. The need for groundwater is increasing with the increase of population,industrialization, agriculture and navigation. Hence the conservation of the groundwater resources in quality and quantity deserves the utmost attention. The quality of groundwater is judged by amount of the dissolved or suspended solutes present in it. The newlineoccurrences of groundwater contamination and quality of groundwater have become major newlineissues, Phenol being a common contaminant. To understand the movement of contaminant in newlinethe groundwater, a sand tank physical model is developed. The tank is 1.5 m long and 0.5 m wide. An injection well and several monitoring wells are installed for measuring heads and contaminant concentrations. Experiments are carried out under simulated in situ conditions, in three stages. In the first stage, the experiments are conducted to study the flow of groundwater under different slope conditions. The second stage of the experiments is conducted to study the transport of Phenol through groundwater aquifer under different slope conditions. PT equation newlineis developed for transport of Phenol. The third stage of the experiments is to conduct newlinebioremediation of Phenol in the physical model. The contaminant concentrations that are tested in above experiments are 100 ppm, 75 ppm and 50 ppm. The slopes for the aquifer are 1: 60 and 1:75. Graded sand in three defined proportions are used as porous media. Samples are collected with time-lapse of 24 hrs after introduction of contaminant into the aquifer to understand contaminant flow and transport. For the bioremediation of Phenol, the readings are taken at the monitoring wells at time intervals of 24 hrs and 36 hrs. The graphs are plotted for newlinedifferent flow and transport conditions. In the final stage, results from the physical aquifer model are validated with numerical model using Meshfree method and a good agreement is observed.