| 滨海盐渍化土壤微塑料赋存特征及影响因素分析 |
| 摘要点击 2907 全文点击 616 投稿时间：2024-07-15 修订日期：2024-10-11 |
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| 中文关键词 土壤 微塑料（MPs） 分布特征 盐渍化 土地利用类型 |
| 英文关键词 soil microplastics （MPs） distribution characteristics soil salinization land use type |
| DOI 10.13227/j.hjkx.202407154 |
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| 中文摘要 |
| 微塑料在陆地和海洋环境中广泛存在,滨海土壤作为陆地和海洋的过渡地带,具有独特微塑料污染特征. 为了揭示滨海盐渍化土壤的微塑料污染特征,在无棣县向海方向采集不同盐渍化程度土壤,通过密度分离、氧化消解和显微-拉曼光谱法识别鉴定,分析了微塑料的分布特征,以及与土壤理化性质之间的关系,采用污染物负荷指数法评估其生态风险. 结果表明,无棣县51个土壤采样点均检测出微塑料,微塑料丰度范围为550~3 950 n·kg-1,聚乙烯（PE）、聚对苯二甲酸乙二醇酯（PET）、聚丙烯（PP）、聚苯乙烯（PS）和聚氯乙烯（PVC）占比分别为：53.1%、13.9%、16.4%、8.4%和8.2%. 微塑料的形状主要包括膜状（62.0%）、纤维状（13.7%）、球状（13.2%）和片状（11.1%）,粒径< 1 000 μm的微塑料占比为85.0%. 微塑料的最低丰度出现在盐渍化程度最高的光板地,最高丰度出现在非盐渍化的棉田土壤中,微塑料丰度与土壤盐渍化程度显著相关（P<0.05）,随盐渍化程度增加,土壤微塑料总丰度,以及膜状、PE和PET微塑料丰度大幅降低（P<0.05）,粒径>1 000 μm的微塑料占比显著降低（P<0.05）,而粒径< 100 μm微塑料占比显著增加（P<0.05）. 这可能由不同盐渍化程度土地利用方式、微塑料来源不同所致. 土壤有机碳（SOC）与微塑料的丰度呈显著正相关（P<0.05）. 土壤微塑料的风险负荷指数（PLI）值在1.19~2.41之间,均为Ⅰ级污染（低风险）,其中盐渍化程度高的荒地和光板地PLI值较低,盐渍化程度低的土壤PLI值较高；研究结果能为认识滨海盐渍化土壤微塑料污染状况,探究土壤性质与微塑料分布特征之间的关系提供重要依据. |
| 英文摘要 |
| Microplastics are widespread in terrestrial and marine environments. As a transition zone between land and ocean, coastal soils have unique microplastic pollution characteristics. To reveal the characteristics of microplastic pollution in coastal soils, soils with different salinization levels were collected from Wudi County toward the sea. The distribution characteristics of microplastics and their relationship with soil physical and chemical properties were analyzed through density separation, oxidative digestion, and micro-Raman spectroscopy techniques. The pollutant load index method was used to assess its ecological risk. The results showed that microplastics were detected in 51 sampling points of coastal soil in Wudi County, and the abundance of microplastics ranged from 550 to 3 950 n·kg-1. Polyethylene （PE）, polyethylene terephthalate （PET）, polypropylene （PP）, polystyrene （PS）, and polyvinyl chloride （PVC） accounted for 53.1%, 13.9%, 16.4%, 8.4%, and 8.2%, respectively. The shapes of microplastics mainly included film （accounting for 62.0%）, fiber （accounting for 13.7%）, sphere （accounting for 13.2%）, and sheet （accounting for 11.1%）. Microplastics with grain size less than 1 000 μm accounted for 85.0%. The lowest abundance of microplastics appeared in the bare land with the highest degree of salinization, and the highest abundance appeared in the non-salinized cotton soil. The abundance of microplastics was significantly correlated with soil salinization levels （P< 0.05）. With saline level increasing, the total abundance of microplastics and the abundance of film, PE, and PET microplastics decreased significantly （P< 0.05）. The proportion of microplastics with grain size greater than 1 000 μm decreased significantly （P< 0.05）, but the proportion of microplastics with grain size less than 100 μm increased significantly （P< 0.05）. This may be because of the different soil use types and different sources of microplastics in soils with varied saline levels. Soil organic carbon （SOC） was significantly positively correlated with the abundance of microplastics （P< 0.05）. The risk load index （PLI） values of all soil samples ranged from 1.19 to 2.41, which were low risk level pollution. Among them, the PLI values of wasteland and bare land with high saline level were lower, and the PLI values of soils with low saline level were higher. The results of this study can provide an important basis for understanding the microplastic pollution and exploring the relationship between soil properties and microplastic distribution characteristics in coastal saline soils. |
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