Arsenic Forms And Their Environmental Characteristics In Sediments

Arsenic is one of the most common and harmful carcinogens in the environment. Arsenicis harmful to health. It can affect the respiratory system, digestive system, cardiovascularsystem, nervous system and hematopoietic system.This paper gives the forms and the primary cause of arsenic contamination. It alsoanalyzes the physical and chemical principle of the arsenic transfer and transformation in soil,groundwater and organisms. The most harmful arsenic contamination for human is soilpollution. The paper analyzes the determination of arsenic in soil and the research methods.Compared the the advantages and disadvantages of the analysis methods (hydride generationmethod, liquid chromatography, gas chromatography, capillary electrophoresis, couplingtechnique), we choose the optimal sequence extraction method to determination and analysisarsenic content in different soil environment.This paper mainly discusses the combined forms of arsenic. The samples werecollectioned from two drillings. It analyzes the5combined forms (exchangeable As, carbonatebound As, Fe-Mn bound As, organic bound As and active As) using sequential extractionmethod by experiment. The extraction order is: exchangeable As, carbonate bound As, Fe-Mnbound As, organic bound As and active As. In the soil samples，the active As content is thelargest, followed by Fe-Mn bound As, carbonate bound As, organic bound As and the contentof the lowest is exchangeable As. The active As nature is stable. Exchangeable As easilytransfer from sediment into solution. When pH falled, the carbonate bound As is more easilyreleased. Fe-Mn bound As released easily in reducing environment. Organic bound As releasedeasily in oxidation environment.Based on the analysis of the combined forms of arsenic, we can further deepen tounderstand the arsenic physiological toxicology and chemical properties. It could find out thereason of arsenic contamination from the source. This has a remarkable ecological benefit andalso has a great significance in environmental protection. It will provide an important referencefor solving the ecological environment effect of high arsenic in soil.