Research on Influences of 'A Test of Different Initial pH from the Reaction' with Properties of Environment Materials on Distribution of Arsenic Speciation Arsenic-Ferric Precipitation

The distribution of arsenic speciation can be applied to elucidate the mechanism of removal arsenic during treatment the water containing arsenic with molysite. In this study, the effect of initial pH on the distribution of arsenic speciation in arsenic-ferric precipitation was determined by a five-step sequential extraction procedure. And then further explore the mechanism of arsenic removal with molysite. This experimental results showed that the main mechanisms governing the arsenic removal with ferric chloride were specific adsorption and coprecipitation. Besides, as pH increased from 5 to 9, the arsenic-ferric coprecipitation played a more and more important role in mechanism of arsenic removal with molysite. At the same time, the water soluble state As and the non-specific adsorption As were barely detectable, which suggested that physical absorption had almost no effect on arsenic removal.