湖南攸县水稻田土壤镉污染评估与控制

发布时间：2018-07-03 13:50

本文选题：水稻田土壤Cd + 水稻田土壤Cd污染特征　；参考：《山西大学》2015年硕士论文

【摘要】：水稻田土壤Cd污染,己成为湖南省攸县发展农业经济的主要制约因素。在对五个主要功能区水稻田土壤Cd污染调查的基础上,分别选择八个有代表性的乡镇作为调查点,对其水稻田土壤、稻谷、灌溉渠道底泥及典型含Cd工业产品和副产品如煤、煤矸石和水等样品进行分析,并根据美国EPA推荐的模型评估当地健康和生态风险。通过设计田间试验,研究经济有效的治理技术,以期对攸县水稻田污染起到一定的控制作用。研究结果表明：(1)以煤矿工厂区和煤矿区为代表的TS和HFQ的水稻土壤Cd含量最高,平均值分别为0.924 mg·kg-1和0.920 mg·kg-1。工业区WL的平均值是0.631 mg·kg-1,为中度Cd污染水平。城镇区具有相似性,其水稻田土壤Cd含量在0.435-0.654 mg·kg-1范围。0-100 cm水稻田土壤Cd含量剖面图显示,除SYT外,其他调查点Cd的积累量在0-20 cm土层变化显著。此外,Cd含量在低于40 cm的剖面深度略有不同,为0.05-0.30 mg·kg-1,属于区域土壤Cd背景值的正常范围。(2)调查表明,水稻田土壤Cd主要的输入途径是灌溉水和大气沉降。8个调查点灌溉渠道底泥Cd的含量都很高,HFQ灌溉渠道底泥Cd的含量达到8.07 mg·kg-1,灌溉水Cd含量为1.42μg·L-1；除了HFQ大气沉降Cd含量仅0.745 g·(hm2·a)-1外,其他调查点均较高,并且TS样点大气沉降Cd含量最高,达12.0 g·(hm2·a)-1,比全国平均水平高出约三倍。总之,攸县水稻田土壤Cd污染无疑是严重和普遍的。(3)8个调查点水稻田土壤Cd含量在0.420-0.924 mg·kg-1之间,都超过了土壤环境质量标准0.3 mg·kg-1,其中51.7%-89.9%的土壤Cd被认为是可利用的有效态。基于土壤和水稻样品,八个调查点PCF的计算值介于0.362-2.78之间。其中五个调查点稻米的PCF值超过了1,表明Cd在植物中积累水平高。攸县稻米Cd含量范围在0.056-1.826 mg·kg-1之间,其中约60%超过世界卫生组织规定的最大安全浓度0.4 mg·kg-1,由于土壤污染浓度的显著上升,约80%研究区的人体健康风险和生态风险较之前都有所提高。总体而言,在整个研究区域中稻田土壤表层Cd的积累量处于高风险状态。另外,对于八个调查点的健康和生态评价结果并不一致,煤矿区HFQ水稻田Cd含量水平高,但其健康风险低(HRI值为1.18),相反,土壤Cd含量相对较低的对照区JS,潜在生态风险(Er为980)和健康风险(HRI为5.96)处于高风险状态,分别排在第一、第二。(4)9种技术处理的水稻田稻谷产量均比对照组低,最低的是石灰和叶面肥处理,分别为737 kg、722 kg,仅为对照组平均值的85%左右。考虑技术成本发现,石灰处理所增加的成本最低为80元,生物碳处理技术增加的成本最高达3200元。综合分析降Cd效果、稻谷产量以及对土壤Cd有效态的影响,表明施用石灰的效果最佳。对不同品种稻米Cd含量的调查分析结果显示：中早39、湘早籼24号、陵两优4024、珍山一号这四个品种采集的所有样品,Cd含量远远超过稻米国家标准0.2 mg·kg-1;而株两优06只有一个样品Cd含量为0.305 mg·kg-1,超过0.2 mg·kg-1的国家标准,其余样品均符合国家稻米Cd含量标准,表明株两优06对Cd的积累明显较其它品种低。
[Abstract]:The soil Cd pollution in paddy field has become the main restriction factor for the development of agricultural economy in Youxian of Hunan province. On the basis of the investigation on the soil Cd pollution in five main functional areas, eight representative towns are selected as the investigation points, and the soil, rice, irrigation channel sediment and typical Cd industrial products and by-products of the paddy soil, rice, irrigation irrigation and irrigation irrigation are selected. Samples such as coal, gangue and water are analyzed, and the local health and ecological risks are evaluated according to the model recommended by the United States EPA. Through the design of field experiments, the economic and effective control techniques are studied to play a certain control role in the pollution of rice fields in Youxian. The results show: (1) TS, represented by coal mining area and coal mining area, and The average value of Cd in the paddy soil of HFQ is the highest, the average value is 0.924 mg. Kg-1 and 0.920 mg. Kg-1. industrial region, the average value of WL is 0.631 mg. Kg-1, which is moderate Cd pollution level. The accumulation of point Cd was significant in the 0-20 cm soil layer. In addition, the depth of Cd content in the section below 40 cm was slightly different, 0.05-0.30 mg. Kg-1, belonging to the normal range of regional soil Cd background value. (2) investigation showed that the main input way of rice field soil Cd was the Cd content of irrigation channel sediment at the.8 investigation point of the irrigation water and the large gas sedimentation. The content of Cd in the HFQ irrigation channel was 8.07 mg. Kg-1, and the Cd content of the irrigation water was 1.42 u g. L-1. Besides the Cd content of HFQ, Cd only 0.745 G. (hm2 a), all the other investigation points were higher, and the concentration of atmospheric sedimentation was the highest, up to three times higher than the national average. In conclusion, Youxian paddy soil soil The soil Cd pollution is no doubt serious and universal. (3) the soil Cd content of the paddy soil in the 8 investigation points is between 0.420-0.924 mg and kg-1, and the soil environmental quality standard is 0.3 mg. Kg-1, and 51.7%-89.9%'s soil Cd is considered to be the available effective state. Based on the soil and rice samples, the calculation value of PCF in the eight investigation points is between 0.362-2.78. The PCF value of rice was more than 1 in five of the survey points, indicating that the accumulation of Cd in plants was high. The Cd content of Youxian rice was between 0.056-1.826 mg and kg-1, about 60% of which exceeded the maximum safety concentration of the WHO, 0.4 mg. Kg-1, and the human health risk and birth of about 80% research areas were increased by the significant increase of soil pollution concentration. In the whole research area, the accumulation of Cd in the paddy soil surface is in high risk. In addition, the results of the health and ecological evaluation of the eight investigation points are not consistent, the HFQ paddy field Cd content in the coal mine area is high, but the health risk is low (HRI value is 1.18), on the contrary, the soil Cd content is relative. The lower control area JS, the potential ecological risk (Er 980) and the health risk (HRI 5.96) were in high risk state, respectively in the first and second. (4) 9 kinds of technology treated rice paddy rice yield was lower than the control group, the lowest was lime and foliar fertilizer treatment, respectively 737 kg, 722 kg, only about 85% of the average value of the control group. Consider the technical results. The lowest cost of lime treatment was 80 yuan, and the cost of the bio carbon treatment was up to 3200 yuan. The effect of reducing Cd, rice yield and the Cd availability of soil showed that the effect of lime was the best. The results of Cd content in different varieties of rice showed that middle early 39, Hunan early indica 24, All the samples collected from the four varieties of mausoleum two, 4024 and Jan. 1, the Cd content was far beyond the national standard 0.2 mg. Kg-1, while the plant two best 06 had only one sample Cd content of 0.305 mg. Kg-1, exceeding the national standard of 0.2 mg kg-1, and the rest of the samples all conformed to the national rice Cd content standard, indicating that the accumulation of plant two and 06 to Cd was obviously more than its accumulation. It is low in variety.
【学位授予单位】：山西大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：S511;X53

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