Numerical Simulation of Remediation of Groundwater Contaminated with Radionuclide and Heavy Metal

Abstract

The colossal use of radioactive materials, fossil fuels and mining activities in the medical field, technological development, power generation and industrial sites has created a great accumulation of radioactive and heavy metal waste. Even a small concentration of this in the environment can have an impact for a longer period. Long term exposure to these leads to an elevated risk of leukemia, leucopenia, kidney damage and genetic damage that can pass into the next generation. Groundwater quality is significantly deteriorated due to radioactive and heavy metal leachate from solid waste landfills, fallouts from nuclear and thermal power plants, etc. Bioremediation techniques are observed to be able to interact with these contaminants and remediate them from the groundwater. newlineThe first part of present study focusses on the experimentation for bioreduction of lead as a contaminant in groundwater. In this study, three biomasses are used which are obtained from Fennel (Foeniculum vulgare) plant as Fennel seeds, leaves and stem to treat the synthetic lead contaminated water sample by biosorption. Physicochemical parameters initial concentration of lead, time of contact, biomass quantity and pH of the solution are assessed. Adsorption equilibrium isotherms are modelled using the Langmuir, Freundlich and Temkin models, where Freundlich model provides the best fit for the biosorption process, with a higher correlation coefficient. The experimental results follow pseudo-second-order kinetic model. The process is exothermic as indicated with a negative gibbs free energy value. This study shows that the Fennel (Foeniculum vulgare) powder is an effective adsorbent for the removal of Lead (Pb) from aqueous solution. newlineThe second part of the study focusses on the simulation of ground water flow and transport using MODFLOW/ MT3DMS model. A three-dimensional real-life case study of Bathinda, Punjab, India is performed for simulation of groundwater flow and uranium/ lead contaminant transport in the groundwater of that district.