PIXE ANALYSIS OF WATER LEAKAGE FROM A LANDFILL SITE OF INDUSTRIAL WASTE GENERATING HYDROGEN SULFIDE

The aim of this study is to develop a method for monitoring water pollution caused by dissolved sulfides and other harmful elements by means of PIXE offering the advantage of multielemental nature, high sensitivity and speed of analysis for a wide variety of samples. Sulfide ions dissolved in an aqueous sample were converted to insoluble CuS compounds and then collected on a thin organic filter suitable as a backing foil for PIXE measurements. The standard method for scavenging CuS precipitate is founded on an investigation of the pH-dependence of the recovery of dissolved sulfides and the calibration curve covering the concentration range from 10 to 1000 ppb. The recovery-factor of CuS showed a maximum value at around pH 8 although it changed with the intrinsic pH of samples. The recovery factor for pH adjusted to 7.50 was kept constant in a wide concentration range of sulfide ions from 10 to 1000 ppb. The concentration of tens of ppm sulfur compound was detected in both drain water from the industrial waste disposal and in peripheral agricultural water, but the fraction of dissolved sulfide was only about 1%. The low concentration of dissolved sulfides was discussed from the viewpoint of the oxidation condition originated from the soluble and insoluble components detected in samples by PIXE analysis.