Abstract

This study explores pollutant behaviour in water and soil environments, specifically focusing on unsaturated soil zones where vertical moisture and contaminant migration predominate. Soil column experiments used undisturbed soil cores from Mangaluru’s coastal sites. A constant-level tank stored seawater and distilled water, introduced from the top, with filtrate collected at the base. Both soil and water samples underwent a comprehensive parameter analysis pre- and post-experiments. The morphology, elemental composition, and mineralogical structure of the collected soil samples were evaluated using scanning electron microscopy, energy dispersive X-ray analysis, and X-ray diffraction. In addition to that, basic soil tests were also performed. The results show that when seawater traversed the undisturbed soil columns, there were reductions in the concentrations of EC, TDS, alkalinity, chlorides, and potassium, alongside an increase in the concentrations of hardness, BOD, and COD. Similarly, when distilled water flowed through the columns, there was an increase in the concentrations of all the parameters. In the realm of soil composition, the introduction of seawater led to declines in the concentrations of available P2O5, calcium, magnesium, zinc, iron, and manganese. In contrast, the passage of distilled water resulted in reductions in EC, available P2O5, K2O, sulphur, calcium, magnesium, zinc, iron, boron and manganese concentrations. These soil analysis findings were congruent with the outcomes of the water analysis, affirming the migration of pollutants from the soil to the water medium. Overall, this study underscores the pivotal role played by soil properties in solute transport and the potential for the movement of pollutants between soil and water environments.