典型污灌区土壤中Cd的形态、有效性及其影响因子

发布时间：2018-01-04 21:34

本文关键词：典型污灌区土壤中Cd的形态、有效性及其影响因子　出处：《中国环境科学》2016年10期 　论文类型：期刊论文

【摘要】：采集了北京、山东、天津、河北及辽宁5个典型污灌区土壤,外源添加1.20mg/kg的Cd,经过30d老化后,研究了不同污灌区土壤中小麦Cd的吸收、转运系数,同时利用离子色谱及WHAM6.0模型对污灌区土壤溶液性质及自由Cd~(2+)形态等进行了测定.结果表明,不同污灌区土壤中,小麦根、茎叶对Cd的富集系数(BCF)与植株体内Cd的根-茎叶转运系数(TF)有显著差异;二种不同Cd敏感性小麦茎叶对土壤Cd的富集系数为0.064~0.465,最大相差626.5%,不同污灌区土壤Cd的富集系数大小表现为辽宁棕壤最大,山东棕壤最小;植株根-茎叶Cd转运系数(TF)表现为河北褐土辽宁棕壤~北京潮土天津潮土山东棕壤.不同污灌区土壤中,自由Cd~(2+)形态含量与Cd植物有效性呈显著正相关;植株根、茎叶中Cd含量与土壤中自由Cd离子含量的负对数[p(Cd~(2+))]呈显著(P0.001)的负相关关系,方程分别为:y=-3.3106x+17.681(R~2=0.929);y=-0.3389x+1.7743(R~2=0.916).外源添加1.20mg/kg Cd土壤中,溶液自由Cd~(2+)形态的变化值[△p(Cd~(2+))]与pH值、EC含量呈正相关,而与溶液中Cl~-、Na~+、Ca~(2+)含量呈负相关.由此可以推断,由污灌引起的土壤中Cl~-、Na~+、Ca~(2+)等离子含量的增加将导致土壤中Cd环境风险增大.
[Abstract]:The soils of Beijing, Shandong, Tianjin, Hebei and Liaoning were collected. After 30 days of aging, 1.20mg / kg CD was added to the soils. The CD uptake and transport coefficients of wheat in different sewage irrigation areas were studied. At the same time, the properties of soil solution and the morphology of free Cd~(2 were determined by ion chromatography and WHAM6.0 model. The results showed that wheat roots were found in different irrigated areas. The enrichment coefficient of CD in stem and leaf (BCFC) was significantly different from that of root-stem-leaf transport coefficient (TFF) of CD in plant. The CD enrichment coefficient of two different CD sensitive wheat stems and leaves was 0. 064 ~ 0. 465, with a maximum difference of 626.5%. The CD enrichment coefficient of soils in different irrigated areas was the largest in Liaoning and the smallest in Shandong. The CD transport coefficient of plant root, stem and leaf (TFF) is the brown soil of Liaoning, Liaoning, and the tidal soil of Tianjin, Tianjin, Hebei, China, and the soil of different irrigated areas. The content of free Cd~(2) was positively correlated with the availability of CD plants. Negative logarithm of CD content in plant root, stem and leaf and free CD ion content in soil. [There was a significant negative correlation between P0. 001 and P0. 001), and the equations were respectively: 1: yr-3. 3106x 17. 681C ~ (2 +) = 0. 929; Yang-0.3389x 1.7743RN _ 2 ~ (0.916). The variation value of solution free Cd~(2) form in soil supplemented with 1.20mg / kg CD. [There was a positive correlation with the content of pH value and a negative correlation with the content of Cl-Na-Na ~ Ca-Ca-2) in the solution. It can be inferred from the result that the content of Cl-Na-Na ~ (2 +) in the solution is negatively correlated with the content of EC. The increase of plasma content in soil caused by sewage irrigation will increase the environmental risk of CD in soil.
【作者单位】：首都师范大学资源环境与旅游学院;中国农业科学院农业资源与农业区划研究所农业部植物营养与肥料重点实验室;
【基金】：国家支撑计划课题(2015BAD05B03) 国家自然科学基金项目(41271490) 国家重点研发计划课题(2016YFD0800707)
【分类号】：X53
【正文快照】： 在农田重金属污染源(大气降尘、污水灌溉、化肥、农药、有机肥及污泥农用等)中,污水灌溉是农田重金属主要污染源之一[1-3].目前,我国每年大约有大约520多亿t废水排放到环境中,其中工业污水达240亿t[4-5].由于水资源匮乏,特别是在我国北方农田,污水常用来农业灌溉,而污灌引起的

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