典型矿物材料钝化修复重金属污染农田土壤的作用及机理研究

发布时间：2018-05-10 14:49

本文选题：土壤 + 重金属　；参考：《浙江大学》2017年硕士论文

【摘要】：随着工、农业的高速发展,大量污染物通过各种途径进入土壤环境中造成土壤污染。农田土壤重金属污染已成为制约我国农业可持续发展的重要因素,修复治理工作刻不容缓。固化/稳定化技术是目前最具应用潜力的重金属污染农田土壤修复技术之一。天然矿物材料,特别是粘土类矿物材料,对重金属有良好的吸附效果,且天然无害,环境友好,价格低廉,在自然界中分布广泛,存量巨大,被广泛用于重金属污染农田土壤钝化修复的研究和应用。本文在评述粘土矿物增强土壤吸附固定重金属研究现状的基础上,研究了鸡粪肥溶出有机质(CM-DOM)对粘土矿物吸附重金属的影响及作用机制;实施了重金属污染农田土壤钝化修复的模拟实验和现场试验,拟为矿物材料钝化修复重金属污染农田土壤提供理论依据与实际案例参考。论文取得了以下有价值的研究成果:(1)探明了 CM-DOM对粘土矿物吸附Cd~(2+)的影响及作用机理,发现CM-DOM显著降低膨润土和沸石对Cd~(2+)的吸附性能,且沸石吸附性能下降程度大于膨润土;发现吸附态CM-DOM对Cd~(2+)吸附的抑制作用是导致粘土矿物吸附性能下降的主要因素;吸附态CM-DOM主要通过位阻效应抑制Cd~(2+)在膨润土表面的吸附,通过对吸附点位的占据作用和位阻效应共同作用抑制沸石吸附Cd~(2+)。(2)实施了矿物材料钝化修复重金属污染农田土壤的模拟实验和现场试验,发现投加1%或2%的沸石、磷灰石,2%膨润土/磷灰石(1:1)及沸石/磷灰石(1:1)能有效降低土壤中Cd、Pb、Zn等重金属的有效态百分含量,且降低程度与土壤pH增加量呈正相关;2%的沸石、磷灰石及沸石/磷灰石(1:1)显著降低了稻米中Cd含量,降低百分率为25.0%-58.9%,其中2%沸石/磷灰石(1:1)的降低效果最好(稻米中Cd含量降低58.9%),且存在协同作用;稻米中Cd含量与土壤中Cd有效态含量变化趋势一致。
[Abstract]:With the rapid development of industry and agriculture, a large number of pollutants have been contaminated by various channels into the soil environment. Heavy metal pollution in farmland has become an important factor restricting the sustainable development of agriculture in China. The remediation and stabilization technology is the most potential heavy metal contaminated farmland soil before the eyes. Natural mineral materials, especially clay mineral materials, have good adsorption effect on heavy metals, and are natural, environmentally friendly, inexpensive, widely distributed in nature and large in stock, and are widely used in the study and application of soil blunt repair in heavy metal polluted farmland. This paper reviews the enhancement of clay minerals in this paper. On the basis of soil adsorption and immobilization of heavy metals, the effect and mechanism of organic matter (CM-DOM) on the adsorption of heavy metals on clay minerals was studied, and simulated experiments and field experiments were carried out to provide a theoretical basis for the restoration of Heavy Metal Contaminated Farmland by the passivation of heavy metals. According to the actual case reference. The paper obtained the following valuable research results: (1) the effect and mechanism of CM-DOM on the adsorption of Cd~ (2+) on clay minerals and the adsorption properties of bentonite and zeolite to Cd~ (2+) were significantly reduced, and the decrease of adsorption properties of zeolite was greater than that of bentonite, and the adsorption CM-DOM was found to adsorb Cd~ (2+). The inhibitory effect is the main factor that leads to the decrease of adsorption properties of clay minerals. The adsorption state CM-DOM mainly inhibits the adsorption of Cd~ (2+) on the bentonite through the steric effect, and inhibits the adsorption of Cd~ (2+) by the occupying and steric effects of the adsorption sites. (2) the passivation of mineral materials is implemented to repair the soil contaminated by heavy metals. Soil simulation and field experiments showed that adding 1% or 2% of zeolite, apatite, 2% Bentonite / apatite (1:1) and zeolite / apatite (1:1) could effectively reduce the content of Cd, Pb, Zn and other heavy metals in the soil, and the degree of decrease was positively correlated with the increase of soil pH, and 2% of the zeolite, apatite and zeolite / apatite (1:1) were significantly reduced. The percentage of Cd in rice was 25.0%-58.9%, and the reduction of 2% zeolite / apatite (1:1) was the best (the Cd content in rice was reduced by 58.9%), and there was a synergistic effect, and the content of Cd in rice was in accordance with the change trend of the Cd content in the soil.

【学位授予单位】：浙江大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：X53

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