| The dredged sediments from Dianchi Lake are rich in organic matter such as N, P and other nutrients, which can improve the capacity of water holding-fertilizer and soil workability and be benefit to the plants growth. Agriculture is one of the main methods of sediment disposal. However, due to heavy metal pollution, limiting its large number of resource utilization.This research studied on four kinds of vegetables:lettuce, Chinese Cabbage, Mustard and Radish which were planted with the dredged sediment as organic fertilizer through pot and field experiment. Select the appropriate dredged sediment, the reasonable way of resource utilization. The main results of this research can be found as follows:(1)The results of Fubao Tang and Baofeng Bay dredged sediment pot experiments show that: The application amount of sediment should be controlled within 5%. And tubers of radish is more suitable for planting in sediment modified soil. Adding modifier of lime can effectively reduce Cu and Cd accumulation in vegetables. But Pb and Zn couldn’t reduce the accumulation in vegetables.(2)In Fubao Tang dredged sediment pot experiment, the BCF values of heavy metal in leafy vegetables were in accordance with Cd> Pb> Zn> Cu, while the BCF values of heavy metal in tuber vegetables corresponded with Cd> Zn> Pb> Cu. The BCF values of heavy metal in other leafy vegetables were in accordance with Cd>Pb>Zn>Cu; while the BCF values of heavy metal in tuber vegetables with Cd>Zn>Pb>Cu. In Baofeng Bay dredged sediment pot experiment, The BCF values of heavy metal in leafy vegetables were in accordance with Cd> Pb> Zn> Cu, while the values in tubers radish were in accordance with Cd> Zn> Pb> Cu. In lime passivation experiments, the BCF values of heavy metal in leafy vegetables were with Pb> Zn; the BCF values of heavy metal in tuber vegetables with Zn>Pb. With the increase of sludge application rate, BCF value increases.(3)Fubao Tang dredged sediment organic matter and other nutrients is far higher than Baofeng Bay dredged sediment, The experimental results of potted vegetables, the former is more suitable for agricultural resources utilization. Therefore, the use of fu bao tong dredged sediment field vegetable application experiment. For field tests, the BCF values of heavy metal in leafy vegetables were Zn> Cd> Pb> Cu, whereas the BCF values of heavy metal in tuber vegetables were Zn> Cd> Cu> Pb. With the increase of sludge application rate, BCF value increases.(4)Average health risk value caused by chemical carcinogens Cd were lower than the international radiation protection (ICRP) committee recommended maximum lifetime acceptable risk level; Non-chemical carcinogenic Pb, Zn, Cu cause health risks by Zn maximum, Pb the second, Cu minimum. and non-carcinogenic health risks were much lower than lifetime acceptable risk level recommended by the British Royal Society, the Swedish Environmental Protection Agency and the Dutch Ministry of Construction and Environment. |
