Showing papers by "Suresh Govindarajan published in 2018"
TL;DR: Health risk assessment was conducted for exposure to PAHs in the ground water using incremental life time cancer risk (ILCR) models coupled with benzo[a]pyrene toxic equivalent method and showed that the cancer risk is predominantly contributed by dermal exposure than the oral in both adults and children.
84 citations
TL;DR: In this paper, a numerical investigation on the interaction of various transport processes of BTEX in a saturated groundwater system is carried out, where the multichannel dissolution from a residual BTEX source under unsteady flow conditions is incorporated in the modeling framework.
Abstract: Interaction of various physical, chemical and biological transport processes plays an important role in deciding the fate and migration of contaminants in groundwater systems. In this study, a numerical investigation on the interaction of various transport processes of BTEX in a saturated groundwater system is carried out. In addition, the multi-component dissolution from a residual BTEX source under unsteady flow conditions is incorporated in the modeling framework. The model considers Benzene, Toluene, Ethyl Benzene and Xylene dissolving from the residual BTEX source zone to undergo sorption and aerobic biodegradation within the groundwater aquifer. Spatial concentration profiles of dissolved BTEX components under the interaction of various sorption and biodegradation conditions have been studied. Subsequently, a spatial moment analysis is carried out to analyze the effect of interaction of various transport processes on the total dissolved mass and the mobility of dissolved BTEX components. Results from the present numerical study suggest that the interaction of dissolution, sorption and biodegradation significantly influence the spatial distribution of dissolved BTEX components within the saturated groundwater system. Mobility of dissolved BTEX components is also found to be affected by the interaction of these transport processes.
10 citations
TL;DR: In this paper, the authors present a numerical model to investigate the migration of BTEX (benzene, toluene, ethylbenzenes, and xylene) within a fractured aquifer system at the scale of a single fracture under the coupled effect of various transport processes such as dissolution, sorption, biodegradation.
Abstract: This paper presents a numerical model to investigate the migration of BTEX (benzene, toluene, ethylbenzene, and xylene) within a fractured aquifer system at the scale of a single fracture under the coupled effect of various transport processes such as dissolution, sorption, biodegradation. The developed model also considers the influence of equilibrium- and kinetic-controlled sorption scenarios on BTEX transport. Further, the transport characteristics of dissolved BTEX within the fracture–matrix system (FMS) are obtained by carrying out the spatial moment analysis on the concentration profiles simulated. In this study, the spatial moment analysis is conducted to estimate the following transport characteristics of dissolved BTEX: (a) velocity within the fracture, (b) dispersion coefficient within the fracture, (c) dissolved mass within the matrix. In order to investigate the sensitivity of various input parameters, two sensitivity indices are computed based on the variation in the velocity of dissolved BTEX constituent within the fracture (SI_vel) and on the variation in the dissolved mass of BTEX constituents within the matrix (SI_mat). Results from the present simulation study suggest that the sorption and biodegradation reactions influence the concentration distribution of highly soluble BTEX constituents (benzene, toluene) within the FMS significantly. The influence of biodegradation on the migration of BTEX within the FMS is found to be more when it co-occurs with the sorption reaction. The effect of sorption and biodegradation reactions on the mobility and dispersion coefficient of dissolved BTEX constituents within the FMS is found to be significant during the early simulation period.
8 citations
TL;DR: In this paper, a numerical model was presented to investigate sequential biodegradation of dissolved benzene, toluene, and xylene (BTX) within a fractured aquifer system under the presence of multi-regions.
Abstract: This study presents a numerical model to investigate sequential biodegradation of dissolved benzene, toluene, and xylene (BTX) within a fractured aquifer system under the presence of multi...
6 citations
TL;DR: In this paper, a numerical model has been developed in order to forecast the U and its progenies concentration in an unsaturated soil, and the developed numerical model is implemented in a hypothetical uranium tailing pond consisting of sandy soil and silty soil types.
Abstract: The uranium ore residues from the legacies of past uranium mining and milling activities that resulted from the less stringent environmental standards along with the uranium residues from the existing nuclear power plants continue to be a cause of concern as the final uranium residues are not made safe from radiological and general safety point of view. The deposition of uranium in ponds increases the risk of groundwater getting contaminated as these residues essentially leach through the upper unsaturated geological formation. In this context, a numerical model has been developed in order to forecast the U and its progenies concentration in an unsaturated soil. The developed numerical model is implemented in a hypothetical uranium tailing pond consisting of sandy soil and silty soil types. The numerical results show that the U and its progenies are migrating up to the depth of 90 m and 800 m after 10 y in silty and sandy soil respectively. Essentially, silt may reduce the risk of contamination in the groundwater for longer time span and at the deeper depths. In general, a coupled effect of sorption and hydrogeological parameters (soil type, moisture context and hydraulic conductivity) decides the resultant uranium transport in subsurface environment.
5 citations
TL;DR: In this paper, a numerical model has been developed for simulating fluid flow in a coupled fracture-matrix system by considering a hyperbolic dominant fluid flow equation within the fracture as against the conventional parabolic dominant liquid flow equation.
4 citations
TL;DR: In this paper, a finite volume method is used to delineate the capture zones and examine the energies within. But, very little research has been reported on the energy of groundwater flow and specifically that associated with the well capture zones.
4 citations