KMS XINJIANG INSTITUTE OF ECOLOGY AND GEOGRAPHY，CAS
| 黄河沉积物微塑料污染及其沉降行为 | |
| Alternative Title | Microplastics contamination and settlement of sediments in Yellow River |
| 龚喜龙 | |
| Subtype | 硕士 |
| Thesis Advisor | 张道勇 ; 潘响亮 |
| 2019-06-30 | |
| Degree Grantor | 中国科学院大学 |
| Place of Conferral | 北京 |
| Degree Discipline | 理学硕士 |
| Keyword | 沉积物 微塑料 丰度 沉降 黄河 Sediments Microplastics Abundance Settlement Yellow River |
| Abstract | 海洋等水体环境中的微塑料( <5 mm)作为一种新型的污染物近年来已逐渐受到国内外的关注。微塑料由于粒径微小，理化性质稳定，难以降解，在环境中可以长期存在，其对环境水质、沉积物及水生生物会造成影响。本研究以我国黄河流域干流和部分水库为研究区域，对该区域沉积物中微塑料的类型、粒径、丰度 等进行了调查。同时选择密度小于水的聚丙烯塑料作为沉降实验的材料，研究了微塑料在棕壤、褐土、栗钙土和黄绵土四种土壤类型模拟溶液中的沉降行为。实验结果可为内陆河流水体环境中微塑料污染治理提供基础性数据，也可为自然水体中塑料的沉降行为的研究提供一定的帮助，本论文的主要研究结果如下：(1) 黄河流域干流调查结果显示：黄河沉积物中的微塑料丰度为 15 ~ 615 个/kg (干沉积物)，其中下游微塑料的丰度明显高于中上游， 粒径主要集中在 1 ~ 4mm 之间，微塑料主要类型依次为碎片类、发泡类、薄膜类和纤维类，聚合物类型为聚乙烯、 聚苯乙烯、 聚丙烯三种，并且研究发现环境中微塑料的表面形态复杂。(2) 微塑料在水库的进水口位置丰度较低，更易在水库储存区部分聚集。 微塑料的平均丰度由上游的水库至下游的水库呈现逐渐增加的趋势。分层采样发现微塑料在表层 0-20 cm 处丰度更高，甚至部分采样点微塑料主要集中在表层 0-10cm。微塑料分为碎片类、发泡类、薄膜类和纤维类四种类型， 显微拉曼鉴定其聚合物成分有聚乙烯、聚苯乙烯和聚丙烯。在各个水库中微塑料粒径分布主要在2 mm 以下。微塑料的颜色分为透明、白色、彩色和黑色，黑色在所有水库中检测到的比例都很小，均不超过 7%。(3) 采用用两种粒径范围的微塑料进行模拟沉降实验，实验结果显示， 500μm 塑料的沉降在低浓度(土壤质量浓度)、高浓度和其他浓度时， 黄绵土、栗钙土、棕壤分别与塑料相互作用最强。 10-50 μm 塑料的沉降效果比 500 μm 塑料的沉降效果更好，通过对粒径分析发现， 20-50 μm 塑料颗粒更易沉降到水底，且沉降速度更快， 在下层沉积物的比例高于上层沉积物。 塑料老化后会降低其在水体中沉降的能力， 而水体盐度的增加会使得更多的塑料漂浮到水面，两者都会降低塑料在沉积物的数量。 |
| Other Abstract | In recent years, microplastics ( < 5 mm)， a new type of pollution, have attractedaround the world in marine and other aquatic environments. Microplastics have asmall particle size, stable physical and chemical properties, and they are difficult tobe degraded, so they can exist in the environment for a long time, which thereforeaffects environmental water quality, sediments and aquatic organisms. In this study,the main stream of the Yellow River Basin and some reservoirs in China were selectedas research areas, and the types, particle sizes and abundances of microplastics in thesediments were investigated. At the same time, polypropylene plastic with density lessthan water was selected as the material of sedimentation experiment. Thesedimentation behavior of microplastics in brown soil, cinnamon soil, chestnut soiland loess soil was studied. The experimental results can provide basic data for thetreatment of microplastic pollution in the inland river water environment, and can alsoprovide some help for the study of the sedimentation behavior of plastics in naturalwaters. The main findings of this thesis are as follows:(1) The results of the main stream survey in the Yellow River Basin show that themicroplastic abundance in the sediments of the Yellow River is 15-615/kg (drysediment), and the abundance of the downstream microplastics is significantly higherthan that in the middle and upper reaches, and the particle size is mainly concentratedin 1-4 mm. Between the main types of microplastics are fragments, foams, films andfibers, the polymer types are polyethylene, polystyrene and polypropylene, and thisstudy found that microplastics in the environment the surface morphology is complex.(2) The microplastics have a low abundance at the inlet of the reservoir and aremore likely to accμmulate in the reservoir storage area. The average abundance ofmicroplastics is gradually increasing from the upstream reservoir to the downstreamreservoir. The stratified sampling found that the microplastics had a higher abundanceat 0-20 cm on the surface layer, and even some of the microplastics at the sampling points were concentrated on the surface layer of 0-10 cm. Microplastics are dividedinto four types: fragment, foam, film and fiber. Raman microscopy identified that thepolymer components were polyethylene, polystyrene and polypropylene. The particlesize distribution of microplastics in each reservoir is mainly below 2 mm. The colorof the microplastics is divided into transparent, white, color and black, and the ratio ofblack detected in all reservoirs is very small, less than 7%.(3) Simulated sedimentation experiments were carried out using microplastics oftwo particle sizes. The experimental results show that the sedimentation of 500micron plastics at low concentrations (soil mass concentration), high concentrationsand other concentrations, respectively, yellow loess, chestnut soil, brown soil and theplastic interaction is the strongest. The sedimentation effect of 10-50 micron plastic isbetter than that of 500 micron plastic. By analyzing the particle size, it was found that20-50μm plastic particles are more likely to settle to the bottom of the water, and thesedimentation speed is faster, and the proportion of sediment in the lower layer ishigher than that of the upper layer. Sediment. Plastic aging reduces its ability to settlein water, and an increase in water salinity causes more plastic to float to the surface,both of which reduce the amount of plastic deposited. |
| Subject Area | 环境科学 |
| Language | 中文 |
| Document Type | 学位论文 |
| Identifier | http://ir.xjlas.org/handle/365004/15327 |
| Collection | 中国科学院新疆生态与地理研究所 研究系统 |
| Affiliation | 中国科学院新疆生态与地理研究所 |
| First Author Affilication | 中国科学院新疆生态与地理研究所 |
| Recommended Citation GB/T 7714 | 龚喜龙. 黄河沉积物微塑料污染及其沉降行为[D]. 北京. 中国科学院大学,2019. |
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