| In order to explore the antimony(Sb)content characteristics and pollution status of the soil and agricultural products around the antimony mining area,and to provide a theoretical basis for the remediation of antimony contaminated soil.Taking the antimony mining area of Xikuangshan in Hunan as the research area,collected 193 pairs of cultivated soil and corresponding agricultural products in different areas around the mining area,and studied the migration and transformation of antimony in the soil-agricultural product system by analyzing the amount of soil antimony,basic physical and chemical properties,and antimony content of agricultural products.Characteristics and evaluation of antimony pollution in soil and agricultural products.Then,using the antimony-enriched plants discovered by the research group in the early stage,combined with the antimony activator screened out in the soil,pot experiment was conducted to study the effects of two antimony-enriched plants on soil antimony absorption and accumulation.The main results are as follows:(1)The total amount of antimony in the cultivated soil of the study area ranges from 39.56 to 8671.83 mg/kg,and the effective state of antimony in the soil ranges from 0.24 to 342.63 mg/kg,accounting for only 0.77% to 1.97% of the total amount of soil antimony.Among them,the antimony content of the farmland in the north area of the mine,the central area of the mine,the south area of the mine,the central township area and the urban-rural transfer area are 151.7±2.42,1470±2.86,884.1±2.63,192.0±2.26 and 179.2±2.62mg/ kg,respectively exceeding the maximum allowable concentration of antimony in farmland soil(31mg/kg)stipulated by the World Health Organization(WHO)by 4.21,40.82,24.56,5.33,4.97 times.The farmland soil in various regions is seriously polluted by antimony.(2)Taking the Hong Kong Public Health and Municipal Service Regulations(PHM-SO)standard(food antimony limit value is 1mg/kg)as the reference standard,the samples of agricultural roots and stem vegetables,onion and garlic vegetables and leafy vegetables in the study area have reached the standards respectively.100%,100% and 88.9%;followed by beans vegetables and solanaceous vegetables,the exceeding rates were 62.50% and 34.78%;melons and fruits vegetables and corn(cereals)exceeding the standard rates were 5.26% and 2.17%.The antimony enrichment coefficients of all types of agricultural products are all lower than 0.1.Among them,the antimony enrichment coefficients of onion,garlic,roots and leafy vegetables are significantly higher than those of beans,melons and fruits,solanaceous vegetables and corn(cereals)(3)The pot experiment showed that the highest enrichment coefficient of the Patrinia villosa was 0.027,and the highest transport coefficient was 0.79;the highest enrichment coefficient of Bidens frondosa was 0.025,and the highest transport coefficient was 0.60.The two plants do not have antimony enrichment characteristics,which are different from those in the early field.The survey results have a large gap.(4)The simulation experiment results of soil antimony activation show that different concentrations of citric acid,triacetic acid,sodium dihydrogen phosphate,sodium silicate and sodium carbonate have varying degrees of activation effects on the three types of soil antimony,and the activation effect is more obvious in the first15 days.As time changes,the activation rate decreases,indicating that the activation effect is not long-lasting.The highest activation rate of soil I after treatment with0.5% sodium dihydrogen phosphate,0.2% sodium silicate and 1% sodium carbonate is 217%,203% and 211% higher than the original soil;soil II is at 0.2% citric acid and 1% carbonic acid.After sodium treatment,the activation rate was increased by277% and 233% at the highest level compared with the original soil;the effect of increasing the activation rate of antimony in soil Ⅲ was not obvious after treatment with different concentrations of activator.The effect of aminotriacetic acid on the activation of antimony in three soils is not obvious.(5)Activator combined with two kinds of plant pot experiment results show that:different activators can promote the accumulation and absorption of antimony in the upper part of Patrinia villosa and Bidens frondosa to varying degrees.Among them,Patrinia villosa after treatment with citric acid,sodium carbonate and sodium silicate The highest antimony content in the shoots was increased by 79.1%,85.3% and94.0% respectively compared with the control group.The highest enrichment coefficients of Patrinia villosa after the treatment of sodium carbonate and sodium silicate were increased by 107% and 91.2% respectively compared with the control group.After sodium silicate treatment,the highest transport coefficient of Patrinia villosa increased by 186% and 94.7%,respectively,compared with the control group;the highest antimony content in the upper part of the Bidens frondosa after the sodium silicate and sodium dihydrogen phosphate treatment increased by 96.0% and77.8 %compared with the control group.the highest concentration coefficient of Bidens frondosa treated with sodium silicate and sodium dihydrogen phosphate increased by 108% and 88.8% compared with the control group.The transport coefficient of Bidens frondosa treated with sodium carbonate and sodium dihydrogen phosphate was the highest than the control group.An increase of 109% and 83.2%. |
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