Spatial Distribution and Seasonal Variations of Heavy Metals in Surface Water of the Taizi River

摘要

The contamination levels and distribution of heavy metals in surface water of the Taizi River were investigated. Samples of water were collected from upstream to downstream locations, and also from the main tributaries of the Taizi River. All samples were analyzed for arsenic, mercury, and chromium (VI). Results indicated that the metal levels of upriver sites were lower than downriver sites. The total concentrations of Cr~(6+) and As in dry season was higher than that in flood season. While heavy metal Hg represents the highest concentration in flood season. Compared with the permissible levels of surface water environmental quality standards (GB3838-2002), the levels of Cr~(6+) and As attained the first and second level, but Hg attained the fifth level. This indicated that most sites of the Taizi River have a high risk of Hg pollution in flood period.