Distribution,Speciation And Bioavailability Of Antimony In Soils

Antimony is a toxic metal element.Due to the development and application of antimony,global pollution has become more and more serious.Many countries and organizations have begun to formulate relevant standard values for the management and evaluation of soil antimony pollution.In this study,the samples from the area where the tailings slurry was leaked and the water contaminated with antimony were used as research samples to investigate the distribution,speciation and bioavailability of antimony in the soil.The conclusion are as follows:1,In this paper,24 soil samples of farmland immersed in sewage containing antimony were collected,and pH,organic matter and cation exchange parameters were determined.The results showed that the pH of the above 24 soil samples did not change markedly,and there was no significant difference.The mathematical mean value was 8.36,so they belong to alkaline soil.The soil organic matter content of the above soil samples varied greatly,and the average organic matter content was 1.47%.The average cation exchange capacity of soil samples was 90.61 cmol/kg,which was relatively high.Through the analysis of soil physicochemical properties and soil antimony morphology,it was found that the content of antimony in the soil was inversely proportional to the pH and organic matter content,and was proportional to the cation exchange capacity.2,The paper determined the total antimony content and chemical form of the 24 soil samples collected.The results showed that:First,the total antimony content of the soil was between 5.15 and 79.08 mg/kg,which exceeded the newly formulated "Soil environmental quality standard for agricultural land" in China.The quality standard gives a limit standard of 3mg/kg,while samples were 0.72～25.36 times higher than the standard.Second,the results of the chemical form of antimony in the soil showed that the proportion of each form were:the average content of the non-specifically sorbed was 2%.The average content of the specifically sorbed was 12%.The average content of the amorphous and crystalline was 26%,and the average content of the residue is 60%.It can be seen from the above data that the residue was dominant,and these forms had a certain relationship with the total amount.3,In this project,the content of antimony in wheat and rape was determined by microwave digestion.In order to further explore the existence pattern of antimony in plants,the samples were distributed and extracted.The contents of various forms in plants were residue state>oxalate state>alcoholic state>protein bound state>water soluble state.4,Through simulated digestion experiments,it was found that about 30%of wheat and rapeseed are excreted in the form of food residues,and 70%of them are absorbed into the digestive juice.At the same time,it was calculated that the consumption of the wheat has a great health risk.5,By adding different remediation agents,it was found that ferric sulfate has a repairing effect on antimony,and calcium-containing substances can be added to alleviate the effect of ferrous sulfate on the residue state.