Research On Heavy Metal Contamination Of Soil And The Cumulative Effect Of Heavy Metals In The Body Of Vegetables In Vegetable Base Of Lanzhou City

In this thesis, study the vegetables base, the polluted situation of heavy metals (Pb, Zn, Cu, Cr and As) in soil and in the body of vegetables in vegetable bases of Lanzhou City wasthe state of the investigated and evaluated, the results showed that:Soil As content in soil of vegetable bases over Lanzhou City soil background value of 139.85% in the 0-20 cm, in the 20-40 cm soil Zn and As contents in soil of vegetable bases over Lanzhou City soil background value of 19.21% and 28.57%. From a single factor pollution index, in the 0-20cm layer of soil, the single-factor pollution index of As in Chengguan District is 2.242, reached a moderate level of contamination, the single-factor pollution index of As in Qilihe District and Gaolan County is between 1-2, which is light pollution; Analysis from the integrated pollution index, the integrated pollution index of heavy metals in soils in Chengguan District is 1.175, which is mild pollution; the integrated pollution index of heavy metals in soils in the whole vegetable bases in Lanzhou City is 0.497, which is the safety area.Content differences analysis of heavy metals in soil at different depths in vegetable base of Lanzhou City showed that the differences of different content of heavy metals in the soil depth; differences analysis of heavy metals in different regions in vegetable base of Lanzhou City showed that the differences of different regions of heavy metals in the soil; cluster analysis of heavy metals in vegetable base of Lanzhou City showed that the area can divided into three main categories, Chengguan district clustered one category, Qilihe district clustered one category, Anning district, Xigu district, Honggu district, Yuzhong County, Yongdeng County and Gaolan County clustered one category, reflecting the combination of heavy-metal contamination in different regions.Analyzed the Pb content of vegetables in vegetable base of Lanzhou City, the Pb content between different vegetables in vegetable base of Lanzhou City showed significant differences; Overall, the Pb content of green onion was significantly higher than other vegetables, tomato was the lowest. The Pb content of the same vegetable between different regions showed significant differences; Overall, the Pb content of Anning district was significantly higher than other districts, Yongdeng county and Gaolan county were the lowest, the Pb content of vegetables and soil was positively correlated.Analyzed the Zn content of vegetables in vegetable base of Lanzhou City, the Zn content of potato, tomato, eggplant, capsicum, green bean, cabbage, and chive in vegetable base of Lanzhou City showed significant differences; Overall, the Zn content of chive was significantly higher than other vegetables, tomato was the lowest. The Zn content of the same potato, tomato, eggplant, capsicum, green bean, and chive between different regions showed significant differences, the Zn content of the cabbage between different regions didn't show differences; Overall, the Zn content of Anning district was significantly higher than other districts, Gaolan county were the lowest. The Zn content of vegetables and soil was positively correlated.Analyzed the Cu content of vegetables in vegetable base of Lanzhou City, the Cu content of potato, tomato, eggplant, capsicum, green bean, cabbage, and chive in vegetable base of Lanzhou City showed significant differences; Overall, the Cu content of potato was significantly higher than other vegetables, tomato was the lowest. The Cu content of the same potato, eggplant, capsicum, green bean, cabbage and chive between different regions showed significant differences, the Cu content of the tomato between different regions didn't show differences; Overall, the Cu content of Gaolan county was significantly higher than other districts, Honggu district were the lowest. The Cu content of vegetables and soil was positively correlated.Analyzed the Cr content of vegetables in vegetable base of Lanzhou City, the Cr content of potato, tomato, eggplant, capsicum, green bean, cabbage, and chive in vegetable base of Lanzhou City showed significant differences; Overall, the Cr content of chive was significantly higher than other vegetables, tomato was the lowest. The Cr content of the same tomato, eggplant, green bean, cabbage,and chive between different regions showed significant differences, the Cr content of the potato and capsicum between different regions didn't show differences; Overall, the Cr content of Anning district was significantly higher than other districts, Xigu district were the lowest. The Cr content of vegetables and soil was positively correlated.Analyzed the As content of vegetables in vegetable base of Lanzhou City, the As content of potato, tomato, eggplant, capsicum, green bean, cabbage, and chive in vegetable base of Lanzhou City showed significant differences; Overall, the As content of chive was significantly higher than other vegetables, cabbage was the lowest. The As content of the same potato, tomato, eggplant, capsicum, cabbage, and chive between different regions showed significant differences, the As content of the green bean between different regions didn't show differences; Overall, the As content of Qilihe district was significantly higher than other districts, Yongdeng county were the lowest. The As content of vegetables and soil was positively correlated.