滇池疏浚底泥中重金属在四种蔬菜中的累积效应及其风险评价

发布时间：2018-01-03 02:33

本文关键词：滇池疏浚底泥中重金属在四种蔬菜中的累积效应及其风险评价　出处：《昆明理工大学》2015年硕士论文　论文类型：学位论文

【摘要】：滇池疏浚底泥富含有植物生长和发育所需的营养物质,例如有机质和N、P等,农用可以改善土壤结构、提高土壤保水肥能力,有利于植物的生长与发育,是底泥处理处置的主要方式之一。但是由于重金属的污染问题,限制了其大量资源化利用的可能性。本研究通过盆栽及田间试验,对生菜、白菜、棒菜和萝卜四种蔬菜施用疏浚底泥作为有机肥进行种植,分析疏浚底泥农用后,其重金属含量对蔬菜的影响,并对其进行风险评价,选择适合的疏浚底泥,采用合理的方式进行资源化利用。研究的主要结果表明：(1)福宝塘疏浚底泥和宝丰湾疏浚底泥盆栽实验结果表明,应将底泥的施用量控制在5%内,而且块茎类的萝卜更适合在底泥改良过的土壤上种植。加入改良剂石灰能有效的降低Cu和Cd在蔬菜中的累积,但不能降低Pb和Zn在蔬菜中的累积。(2)福宝塘疏浚底泥盆栽试验中叶菜类作物空白对照重金属BCF大小为CdZnPbCu,对于块茎类作物空白对照组重金属BCF大小为ZnPbCdCu。其余叶菜类组分重金属富集能力大小均符合CdPbZnCu,而块茎类组分重金属BCF大小均符合CdZnPbCu。石灰钝化实验中块茎类蔬菜萝卜的空白对照组中重金属BCF大小为CdZnPb,其他组分中重金属BCF大小为ZnPb。宝丰湾疏浚底泥实验中叶菜类蔬菜重金属BCF大小为CdPbZnCu,对于块茎类萝卜重金属BCF大小为CdZnPbCu。石灰钝化实验中叶菜类蔬菜重金属BCF大小为PbZn,对于块茎类的萝卜重金属BCF大小为ZnPb。随着疏浚底泥施入量的增加,BCF值也随之增大。(3)福宝塘疏浚底泥有机质等营养元素远高于宝丰湾疏浚底泥,且由盆栽蔬菜实验结果可知,前者更适合用于农用资源化利用。因此,采用福宝塘疏浚底泥进行田间蔬菜应用实验。田间试验中,叶菜类蔬菜种植应将底泥的施用量控制在1.6 kg.m-2以下,块茎类蔬菜种植应将底泥的施用量控制在2.4 kg.m-2以下。叶菜类作物重金属富集能力大小均为ZnCdPbCu,茎块类作物重金属富集能力大小为ZnCdCuPb。随着疏浚底泥施入量的增加,BCF值也随之增大。(4)盆栽试验和田间应用试验中,化学致癌物Cd引起的平均健康风险均低于ICRP推荐的最高终生可接受的风险水平3.5×10-3；而非化学致癌物P、Zn、Cu引起的健康风险以Zn最大,Pb次之,Cu最小,英国皇家协会、瑞典环境保护局及荷兰建设环境部等推荐的终生可接受风险水平为7×10-5,而上述非化学致癌物引起的健康风险均低于以上水平。而儿童的健康风险大于成人。
[Abstract]:Dianchi Lake dredged sediment is rich in nutrients needed for plant growth and development, such as organic matter and Nu P, etc. Agriculture can improve soil structure, increase soil moisture and fertilizer capacity, and facilitate plant growth and development. It is one of the main methods of sediment treatment and disposal. However, due to the pollution of heavy metals, the possibility of a large number of resource utilization is limited. In this study, lettuce and cabbage were treated by pot and field experiments. Four kinds of vegetables were planted with dredged sediment as organic fertilizer. The effect of heavy metal content on vegetable was analyzed after dredged sediment was used for agriculture. The risk was evaluated and the suitable dredged sediment was selected. The main results of this study are as follows: 1) the results of potted experiments on dredged sediment of Fubaotang and Baofeng Bay show that the application amount of sediment should be controlled within 5%. And tuber radish is more suitable to be planted on the improved soil. The addition of lime can effectively reduce the accumulation of Cu and CD in vegetables. However, the accumulation of Pb and Zn in vegetables could not be reduced. 2) in the pot experiment of dredged sediment in Fubaotang, the size of heavy metal BCF of leaf vegetable crops was CdZnPbCu. For tuber crop blank control group, the size of heavy metal BCF was ZnPbCdCu.The enrichment ability of other leaf vegetables was in line with CdPbZnCu. The size of heavy metal BCF in tubers was consistent with that of CdZnPbCu.The size of BCF in the blank control group of tuber vegetables and radish was CdZnPb in calcareous passivation experiment. The size of heavy metal BCF in other components was ZnPb.In the experiment of dredging sediment in Baofeng Bay, the BCF size of heavy metal in vegetables was CdPbZnCu. For tuber radish, the BCF of heavy metal was CdZnPbCu.The heavy metal BCF of leafy vegetables was PbZn in calcareous passivation experiment. For tubers, the size of heavy metal BCF was ZnPb, which increased with the application of dredged sediment. BCF value also increased. 3) the nutrient elements such as organic matter in dredged sediment of Fubaotang were much higher than those in Baofeng Bay, and the results of potted vegetable experiment showed that the former was more suitable for agricultural resource utilization. The field vegetable application experiment was carried out by using the dredged sediment of Fubaotang. In the field experiment, the application rate of the sediment should be controlled below 1.6 kg.m-2 for the planting of leafy vegetables. The application rate of sediment should be controlled below 2. 4 kg.m-2 in the cultivation of tuber vegetables, and the enrichment ability of heavy metals in leafy vegetables should be ZnCdPbCu. The enrichment capacity of heavy metals in stem block crops was ZnCdCuPb.BCF value increased with the application of dredged sediment. The average health risk caused by chemical carcinogen CD was lower than the highest lifetime acceptable risk level recommended by ICRP (3.5 脳 10 ~ (-3)). However, the health risk caused by non-chemical carcinogen Pu ZnN Cu was the lowest in Pb, followed by Zn, and the lowest in Royal Society of England. The lifetime acceptable risk level recommended by the Swedish Environmental Protection Agency and the Netherlands Ministry of Construction and Environment is 7 脳 10 ~ (-5). The health risks associated with these nonchemical carcinogens are lower than those above, and the health risks of children are higher than those of adults.
【学位授予单位】：昆明理工大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：X53;S63;X82

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