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Seasonal and Vertical Variability of Acid-Volatile Sulfide in the Sediments of Taohua River, China

Acid volatile sulfide (AVS) mainly controls the chemical activity and toxicity of heavy metals in sediment. The main aim of this paper is to investigate the seasonal and vertical variability of AVS in the sediments of Taohua River, Guilin, China. By means of acidification - gas blowing, the AVS content of 11 surface sediment samples, collected respectively in April, August and December 2004, was determined to identify the seasonal effect. Three sediment cores were collected from different depth and analyzed in order to reveal the vertical distribution of AVS. Our results indicate that the AVS mean value is 0.6068µmol/g (dry sediment) in April, 31.3297µmol/g (dry sediment) in August, and 0.5727µmol/g (dry sediment) in December, respectively, showing that the AVS content reaches the highest in Summer, lowest in Winter, and intermediate value in Autumn and Spring. The AVS concentration also varies with depth: it increases with depth at beginning, and then drops down as the depth continuously becomes greater.