乐安河洪泛区土壤—蔬菜重金属污染特征及风险评价

发布时间：2018-01-12 22:14

本文关键词：乐安河洪泛区土壤—蔬菜重金属污染特征及风险评价　出处：《南昌工程学院》2017年硕士论文　论文类型：学位论文

【摘要】：土壤环境是人类生存的重要基础,土壤安全对人类安全来说至关重要。重金属可以通过多种途径进入土壤,通过富集作用进入蔬菜体内,造成蔬菜发育不良和减产同时人类食用受污染的蔬菜健康会受到严重威胁。本文选取受重金属污染的乐安河洪泛区村落菜地土壤和蔬菜为研究对象,共选取了9个典型村庄的蔬菜地,采集土壤和蔬菜样品,实验测定6种重金属(Cu、Cr、Zn、Pb、Cd、As)的总量和形态,分析土壤重金属总量和形态空间分布特征和蔬菜的富集能力、蔬菜的综合污染指数。主要结论有:(1)研究区域村落菜地土壤中Cu、Cr、Zn、Pb、Cd、As总量的变化区间为30.59~2700.78mg/kg,60.12~350.24mg/kg,51.29~3600.19mg/kg,70.26~1400.22mg/kg,5.34~85.25mg/kg,3.21~261.21mg/kg,6种重金属的含量均高于鄱阳湖流域背景值,Cu、Zn、Pb总量的高值均出现在戴村,Cr总量高值出现在刘三村,Cd总量高值出现在中垴村,As总量高值出现在虎山湾。利用反距离权重插值法对研究区域内重金属总量的空间分布特征进行直观的表示,结果表明,不同重金属在不同村落菜地分布差异性较大,污染程度也不同,从形态来说,不同重金属的形态在菜地土壤中差异性较大,同一重金属的不同形态的分布规律也不尽相同,表现出较大的差异性。(2)运用单因子污染指数法、内梅罗综合指数法、地质累积指数法、潜在生态风险指数法对研究区域内村庄菜地土壤进行评价,结果表明,戴村Cu、Zn、Pb处于强污染状态,Cr、As、Cd处于中强污染状态,潜在生态风险指数法表明戴村的菜地土壤受到强污染,具有较大的生态危害性。m:口的菜地土壤用这四种评价方法得到的结果一致,表明该区域处于严重污染状态。兰坑村的菜地土壤Cu、Pb为中度污染,Cr、Cd、As为轻度污染状态;潜在生态指数法表明该区域处于较轻生态危害状态。刘三村处于较低生态危害级别,生态威胁性较低。韩家村Cu、Pb、Zn为中度污染,As、Cd为轻度污染,潜在生态危害指数法表明该村的的生态危害性较低。中垴村处于中等生态危害级别。刘家山、叶家村、虎山湾的污染程度为中等污染水平,从整体上看,研究区域污染较为严重,生态危害性较高。(3)对研究区域的蔬菜重金属空间分布特征进行分析,结果表明,不同重金属在不同蔬菜中的含量呈现出差异性,整体来看,Cu在整个研究区域的白菜中含量相对较高,萝卜和大蒜的含量差异性不大,菠菜和辣椒的差异性性较小。Cr的含量在整个研究区域的含量相对较低,萝卜和大蒜中Cr的相对于白菜、菠菜和辣椒的含量要高。Zn含量在不同村落的含量均较高,并且白菜、萝卜、大蒜、菠菜的含量要比辣椒要高很多。Pb的含量要比Zn的含量要低,并且每种蔬菜中Pb的含量也不尽相同。Cd和As在整个研究区域的含量较低。(4)对白菜、萝卜、大蒜、菠菜、辣椒这五种蔬菜对重金属的富集能力研究发现Cu的富集能力最强,每一种蔬菜对重金属的富集能力也不相同。综合污染指数表明白菜的综合污染指数最高,表明白菜受污染最严重。总体上看五种蔬菜对重金属都有一定的富集能力。
[Abstract]:Soil environment is the important foundation of human survival, the safety of the soil is essential to human safety. Heavy metals can enter the soil through a variety of ways, enter the body through the enrichment of vegetables, vegetable production and cause stunted growth and human consumption of contaminated vegetables and health will be a serious threat. The pollution of heavy metals in Le'an River floodplain village vegetable soil and vegetables as the research object, selects 9 typical villages of vegetables, soil and vegetable samples, determination of 6 heavy metals (Cu, Cr, the Zn, Pb, Cd, As) of the total amount and morphology, analysis of characteristics and enrichment ability of vegetable distribution and morphology of soil heavy metals, comprehensive the pollution index of vegetables. The main conclusions are: (1) the study area of village vegetable soil Cu, Cr, Zn, Pb, Cd, As of the total change interval is 30.59~2700.78mg/kg, 60.12~350.24mg/kg, 51.29~3600.19mg/k G, 70.26~1400.22mg/kg, 5.34~85.25mg/kg, 3.21~261.21mg/kg, 6 kinds of heavy metals in the Poyang Lake River Basin were higher than the background value, Cu, Zn, high value of total Pb were found in the Dai village, high total Cr value appeared in Liu San Cun, the total Cd high values appear in the NAO village, high total As value now. The use of tiger Bay inverse distance weighted interpolation method based on the total amount of heavy metals in the study area of the spatial distributions of visual representation, the results show that the different heavy metals in different villages of vegetable distribution, pollution degree are different from the form, different forms of heavy metals in vegetable soil differences, different forms of the same heavy metal distribution are not the same, showed great differences. (2) using the method of single factor pollution index, Nemero index, geoaccumulation index, the study area village dish method of potential ecological risk index Evaluation of soil, the results show that the Dai village of Cu, Zn, Pb in the strong pollution, Cr, As, Cd in the moderate pollution, potential ecological risk index method show that the Dai village vegetable soil by heavy pollution, with greater ecological harm.M: in vegetable soils obtained by these four kinds of evaluation methods the results show that, the area is seriously polluted. LAN Keng Village Vegetable Soil Cu, Pb, Cr, Cd, moderate pollution, light pollution, As state; potential ecological index method shows that the area is lesser. The ecological risk of Liu in the low level ecological harm village, ecological threat is low. Han the village of Cu, Pb, Zn, As, Cd, moderate pollution, light pollution, potential ecological risk index shows that the village ecological risk is low. In the NAO Cun is in the middle level ecological harm. Liu Jiashan, ye Jia Cun, Shan Bay pollution degree is moderate pollution level, from the whole The physical point of view, the study area is more serious pollution of ecological hazard is higher. (3) of the study area to analyze the spatial distribution of heavy metals in vegetables, the results show that the content of different heavy metals in different vegetables shows differences, overall, relatively high content of Cu in the study area in the domain of Chinese cabbage, little the difference of content of radish and garlic, pepper and content of spinach difference less.Cr content in the study area is relatively low, and garlic in Cr compared with turnip cabbage, spinach and pepper have higher content of.Zn contents in different villages were higher, and Chinese cabbage, radish, garlic, spinach content want to be lower than the Zn content than to many.Pb high content of pepper, and the content of each vegetable in Pb are not the same in.Cd and As content in the study area is low. (4) of Chinese cabbage, radish, spinach, garlic, pepper These five kinds of vegetables of accumulation ability of heavy metals found the enrichment ability of Cu is the strongest, the enrichment ability of every kind of heavy metals in vegetables is not the same. The comprehensive pollution index shows that the comprehensive pollution index of Chinese cabbage cabbage showed the highest, most polluted. The overall look of the five kinds of vegetables have some ability to accumulate heavy metals.

【学位授予单位】：南昌工程学院
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：X53

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