Appraisal of Electrical Resistivity Tomography and Hydro-Geochemistry Applications for Demarcating and Understanding the Behaviour of Chromium Mobilization in Porous and Fractured Media
摘要
Bangalore, one of India’s major industrial hubs, faces increasing issues with groundwater and soil pollution, primarily due to unregulated industrial discharges. These activities alter the chemical composition of groundwater, compromising its potability and posing significant risks to public health and environmental sustainability. To address this, a multi-disciplinary approach combining Electrical Resistivity Tomography (ERT) with hydro-geochemical analysis offers valuable insights. This integrated method enhances the understanding of chromium mobilization and transport within porous and fractured geological media, enabling more effective identification of contamination zones and guiding remediation strategies. The influence of groundwater regimes associated with industrial activities can be assessed quickly through the ERT inverse pseudo-section model. Results revealed that integrating geochemical (water and soil) and resistivity studies is essential for achieving a high success rate in identifying contaminated zones and understanding subsurface hydrogeological conditions for the mobilization of ions/metals. TDS varied from 580 to 3300 mg/L in July 2016, from 340 to 6700 mg/L in January 2017, and from 380 to 5660 mg/L in August 2017 in groundwater samples. The variation in the TDS values is due to precipitation occurring during rainy and dry periods. The Cr+3 concentration in groundwater ranges from 0.0011–33.9 mg/l (July 2016), 0.0040–15.05 mg/l (January 2017) and 0.00012–26.12 mg/l (August 2017), and Cr+6 ranges from 0.0005–0.076 mg/l (July 2016), 0.09–14.3 mg/l (January 2017) and resistivity for the contaminated site ranges from 0.738 to 8.70 Ohm-m in the industrial area. Outside the industrial area, a quite normal range of resistivity, ranging from 31.7 to 47.7 Ohm-m, was observed, indicating the groundwater regime was not affected by industrial effluents. Tracking variations helps evaluate natural attenuation and remediation strategies. Integrated studies identify contamination sources to promote sustainability, ecology, and environmental health, thereby protecting groundwater resources essential for human survival.