关键词: 桃江, 沉积物, 钨, 赋存形态, 释放规律

Abstract:

The tungsten mining in southern Jiangxi has a history of 100 years. The heavy metal pollution of river depositions in the mining area poses a threat to the water environment. In order to explore the enrichment, occurrence and release of tungsten in the depositions of the Gannan River, the typical tungsten mining area in southern Jiangxi is selected. The Taojiang River was used as the research object. 36 surface deposition samples from the three water periods of Taojiang wet period-flat water period - dry season were collected and the total amount of tungsten was measured. The morphology of tungsten was analyzed by BCR three-step method and inductively coupled plasma mass spectroscopy. The simulation experiment explored the release law of deposition tungsten. The results showed that the content of tungsten in the surface depositions of the three water periods ranged from 0.91mg/kg to 159.94mg/kg, and the average value was 25.36mg/kg^{. The total content order of heavy metals was in dry season > wet period > flat water period, and the average tungsten content of 79.67% of the three water periods exceeded the soil background value of Jiangxi Province, the highest exceeded 39 times; the morphological analysis results showed that the main occurrence forms of tungsten in the three water periods were residual state, the proportion values were 80.38%, 91.59% and 86.71%, respectively, and the proportion of bioavailable states was relatively small, indicating that the ecological risk of heavy metal tungsten in the depositions of Taojiang was small. The results of single factor experiment showed that the release of tungsten in the depositions increased under the conditions of weak acid, high temperature and high concentration of NH₄ +, and the order of release of tungsten in the three water periods was in the wet season > flat water period > dry season, indicating that the unique water quality environment in Gannan was conducive to the release of tungsten from depositions.}

Key words: Taojiang River, deposition, tungsten, occurrence form, release law