Distribution of highly arsenic and fluoride contaminated groundwater from east Punjab, Pakistan, and the controlling role of anthropogenic pollutants in the natural hydrological cycle

摘要: 91% exceeded the WHO standard (10 µg/L) for As and 75% (1.5 mg/L) F ‐ . The highly contaminated (max. 2400 22.8 groundwaters were found from shallow depths down to 30 m surface. are characterized by high pH 8.8), alkalinity (HCO3 up 1281 mg/L), SO4 2‐ 960 Na + 1058 maximum electric conductivity >4.6 mS/cm. Fluoride concentrations showed positive correlations with those of HCO 3 negative ones Ca 2+ Mg alkaline waters saturated calcite in spite low concentrations. concentration is governed fluorite solubility. Speciation analysis mostly form V There was a correlation between pH, while there no relationship vs. Fe Thus, fluoride contamination occurred oxidizing conditions groundwater. However, derived two or more sources. Suspected contaminant sources study area contained considerable amounts As; fertilizers (DAP, n = 5) leachable ranging 53‐255 mg/kg, 5‐10 coals (n 8) 5‐20 mg/kg. Sulfur isotopic ratios indicated that SO 4 groundwater (3.2‐7.0‰, CDT) mainly coal combusted atmospheric pollutants, household wastes. Nitrogen isotope data (8‐30‰, Air) NO3 ‐N attributed animal waste distributed area. major chemical characteristics related anthropogenic activities on ground resultant chemistry, especially concentrations, must promote studied groundwaters.