Subjects: Other Disciplines >> Synthetic discipline submitted time 2023-03-19 Cooperative journals: 《中国科学院院刊》
Abstract： Microplastic pollution problems in freshwater environment have attracted growing attention from scholars at home and abroad. This work reviewed the research progress on microplastics in freshwater environment in China, analyzed the sources, environmental behavior and fate of microplastics in freshwater environment, and discussed the ecological environment effect of microplastic pollution. Studies showed that microplastic pollution is ubiquitously presented in rivers and lake in China. Microplastics have been detected with abundances up to 107 items/km2 in freshwater, which is higher than those reported from marine environment. Microplastics detected in the freshwater environment showed different shape, size, and color features, are made from different polymer types, and are able to carry other contaminants. These features partly reflect the source and experience of microplastics, and are related to their environmental behavior and ecological environment effect. Research has also demonstrated that microplastics are commonly presented in fishes and mollusks collected from freshwater environment, microplastic exposure is able to affect the health of individual organisms as well as alter the structure and function of ecosystem. Therefore, microplastics are considered as emerging contaminants. In view of the microplastic pollution status and problem in freshwater environment, microplastic pollution control strategies were proposed based on watershed management thought. It is suggested that China should further improve the relevant policies and regulations, strengthen the implementation of policies and regulations, so as to ensure the health of freshwater ecosystem and the sustainable use of freshwater resources.
Subjects: Other Disciplines >> Synthetic discipline submitted time 2023-03-19 Cooperative journals: 《中国科学院院刊》
Abstract： Marine microplastic pollution considered as an emerging environmental problem has been highly recognized worldwide. Comparatively, no such attention has been paid on soil microplastic pollution especially in agricultural land. This paper reviews research progress in sources, accumulation, degradation, transport, and potential risks in eco-environment and food chain, and suggests relevant countermeasures in governance and research. It is also pointed out that microplastics may enter into the agricultural soils through various sources and pathways, including agricultural film breaking, organic manure application, water irrigation, sewage sludge utilization, atmospheric deposition, and surface runoff, and then accumulate in surface layer, while animal and possibly edible plants grown in soils, likely posing risks on ecosystem and food chain. However, the accumulation, forms, movement, degradation of microplastics in soil-animal-plant systems and their risks on eco-environment, food chain, and human health have been poorly understood. It is also lack of study and awareness in good measures for prevention, control, and remediation of microplastic pollution in soil. Therefore, the study also put forward to attach importance of research in microplastic pollution and treatment in soil for prevention of ecological and food chain risks. It is suggested that China should speed up the establishment of analytical methodology for soil microplastic study and accelerate deployment strategy for systematic research in soil microplastic pollution and treatment, aiming at understanding accumulation, release, transformation, and their eco-environmental effects of microplastics and corresponding additives and metabolites in soil, evaluating potential impacts of microplastics and its attached pollutants on risks to soil biotas, ecosystem, and food chain, and constructing technology systems for source control and remediation of microplastic pollution in soil. Thus, both scientific basis and technological support can be well provided for governance and treatment of microplastics in soil and terrestrial ecosystems in China.
Subjects: Environmental Sciences, Resource Sciences >> Basic Disciplines of Environmental Science and Technology submitted time 2020-06-21 Cooperative journals: 《干旱区研究》
Abstract：微塑料（<5 mm）对于环境的污染越来越受到社会的关注，本文以黄河流域采集的沉积物为研究对象，通过密度浮选的方式提取其中的微塑料，统计了沉积物中微塑料的丰度、类型、颜色和粒径分布，同时，利用傅里叶红外光谱仪和扫描电镜-能谱仪（SEMEDS）分析微塑料的组成和表面形貌特征。结果表明：① 微塑料的丰度为15~615个·kg-1（干沉积物），下游沉积物中微塑料的平均丰度高于中、上游。主要包括碎片类、发泡类、薄膜类和纤维类4种类型，其中碎片类所占的含量最高，为43.35%，其次是发泡类塑料，约占34.08%，薄膜类和纤维类相对较少，两者之和为20.56%。② 不同形状塑料的红外光谱分析表明：碎片类微塑料的主要成分是氧化聚乙烯，薄膜类的主要成分是聚丙烯，发泡类和纤维类微塑料的主要成分分别是聚苯乙烯和聚乙烯。③ 微塑料的颜色分为透明、白色、彩色和黑色4种，其中透明和白色所占的比例较高，分别为43.28%和34.55%。微塑料的粒径特征表明，其粒径范围主要位于1~4 mm，占比为64.8%，<1 mm的微塑料所占比例为16.62%。④ 微塑料表面形貌特征表现为，微塑料有不同程度的老化痕迹，具有表面粗糙、孔隙多、裂隙明显等特点。
Subjects: Environmental Sciences, Resource Sciences >> Basic Disciplines of Environmental Science and Technology submitted time 2020-04-26 Cooperative journals: 《干旱区研究》
Abstract：博斯腾湖人工湿地是典型的多级表面流污水人工湿地处理系统。本研究采集博斯腾湖人工湿地各级子系统进水和出水口的水样及沉积物，通过高通量测序技术，分析了多级湿地系统中水和沉积物中的微生物群落空间分布特征。结果表明：总体上人工湿地沉积物中的微生物多样性和丰度高于水体。在多级湿地系统中微生物群落丰度及多样性自入口起始，先增加后由潜流湿地排入博斯腾湖后减小。水中核心门类为变形菌门（Proteobacteria）、厚壁菌门（Firmicutes）、放线菌门（Actinobacteria）及浮霉菌门（Planctomycetes）。其中变形菌门整体呈上升趋势，从初始进水口的59.11%上升至最终出水口的84.80%，而厚壁菌门类整体呈下降趋势，从24.05%降至6.83%。但厚壁菌门类细菌仍是优势菌种，这表明该门类细菌在废水处理系统中是优势菌种。沉积物中变形菌门类和厚壁菌门类细菌依然占主导地位，厚壁菌门类细菌丰度也是先增加后减少，而变形菌门类细菌整体上随处理深度呈下降趋势；拟杆菌门（Bacteroidetes）和绿弯菌门（Chloroflexi），两者在整个处理过程中呈现出完全相反的趋势。尽管水和沉积物中优势门类细菌均为变形菌门，并且最主要的功能类群均为氨基酸运输和代谢，但微生物群落整体结构及功能仍显著不同。
Subjects: Environmental Sciences, Resource Sciences >> Basic Disciplines of Environmental Science and Technology submitted time 2018-09-03 Cooperative journals: 《干旱区研究》
Abstract：新疆农田土壤及周边河湖沉积物中酞酸酯污染非常严重，由于干旱的气候条件，现有微生物修复技术往往难以适用治理新疆地膜造成的酞酸酯污染。因此，迫切需要研发酞酸酯污染土壤及水体的修复技术及材料。基于应用材料表面的强疏水性对酞酸酯的优异吸附性能的原理，采用多巴胺聚合将3种纳米颗粒（BN、SiO2、Fe3O4）改性得到疏水性良好的材料，并通过SEM-EDS、ATR-FTIR光谱、Raman光谱、N2吸附脱附曲线等对改性材料进行表征。以新疆地膜污染土壤中常见的酞酸酯、邻苯二甲酸二丁酯作为目标污染物进行吸附性能实验，结果表明：所研发的改性材料对邻苯二甲酸二丁酯具有良好的吸附效果，平衡吸附量可达218.63 mg·g-1；吸附可以在220 min内达到平衡，吸附动力学符合准二级动力学方程；吸附等温线用Langmuir与Freundlich模型均能良好的拟合，后者的相关性更好；并在pH（2~12）与氯化钠盐度 （高达4%）下，材料就能保持良好的吸附效果。该材料在修复干旱区酞酸酯污染土壤、沉积物及水体中具有广阔应用前景。
Subjects: Environmental Sciences, Resource Sciences >> Basic Disciplines of Environmental Science and Technology submitted time 2018-09-03 Cooperative journals: 《干旱区研究》
Abstract：如何提高盐碱土中磷养分的植物有效性是盐碱地农业的重要研究课题。聚谷氨酸（γ-PGA）被认为具有良好的保肥性能和缓释肥性能，但是其内在机理并不清晰。本文通过模拟盐溶液蒸发结晶实验，应用盐溶液pH和电导率（Electricity conductance）的在线测定、盐溶液各组分之间及各组分与γ -PGA相互作用的热动力学参数测量，研究了聚谷氨酸抑制盐溶液中钙质磷酸盐沉淀的机理。实验表明，随着蒸发过程，盐溶液的pH总体上为先持续上升然后持续下降。当γ-PGA存在时，pH从上升变为下降的拐点所需的时间明显延长，这说明γ-PGA显著延缓了钙质矿物（如HAP和碳酸钙）的沉淀生成。 这种延缓作用主要与γ-PGA和各种盐分离子之间络合作用的显著差异相关。虽然HPO42--Ca2+络合物的稳定性大于γ-PGA-HPO42-及γ-PGA-Ca2+，但γ-PGA可以为Ca2+提供的结合位点数高出HPO42--Ca2+两个数量级，盐溶液中大量的Ca2+被γ-PGA络合，从而抑制了HPO42--Ca2+的反应及随后磷酸钙类矿物的沉淀。虽然γ-PGA可延缓钙质矿物的沉淀形成，但对溶液完全蒸发后产生的结晶产物没有明显影响。实验结果表明，γ-PGA可通过抑制磷酸盐与Ca2+形成沉淀，而提高盐碱土中植物对P养分的利用效率，通过与HPO42-形成高稳定的络合物起到P肥缓释剂的作用。γ-PGA在实际土壤溶液和土壤中的应用还需要进一步研究。
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