Department of Earth Sciences, College of Science, Shiraz University, 71454 Shiraz, Iran.
Department of Earth Sciences, College of Science, Shiraz University, 71454 Shiraz, Iran.
Sci Total Environ. 2022 Jul 15;830:154728. doi: 10.1016/j.scitotenv.2022.154728. Epub 2022 Mar 22.
The occurrence of microplastics (MPs) was investigated in the Arvand River (Iran). The Arvand River (200 Km) is a major water body that flows through land with diverse use and it meets the Persian Gulf. This study constitutes the first assessment of MP pollution (prevalence and physico-chemical characteristics) in the Arvand river, both in the sediment and in the water. MP monitoring has been carried out in 24 stations located along the river. The MP pollution found ranged between 1 and 291 items·L and 70 to 15,620 items·kg (dw), in water and sediment, respectively. The majority of MPs were fibres, black/grey and yellow/orange in colour, and mainly 250-500 μm and >1000 μm in size. Polyethylene terephthalate (PET), polypropylene (PP), nylon (NYL), high-density polyethylene (HDPE), and polystyrene (PS) were found in sediment samples. All these polymers, except HDPE, were also identified in the water samples. PET and PP were dominant in the water samples; whereas PET and PS were the most abundant in the sediments. The vicinity of urban wastewater effluents could be behind MP pollution in both water and sediments. Significant differences (p < 0.05) of MP concentrations were affected by different land uses when comparing MP levels in undisturbed natural area with urban areas. A strong correlation between MP fibres and fragments found with PCA biplots revealed their similar distribution in water. In the sediment samples, fibre and fragment MP particles were significantly correlated with colloidal particles (e.g., clay and organic matter) suggesting a relevant role of colloidal particles in the aquatic ecosystem of the Arvand River in transporting MPs. This study contributes to the better understanding of the presence of MP in major rivers, which are systems that have been scarcely investigated for this type of pollution, and it can inform interventions to reduce MP inputs to the river and sea.
本研究对流经多种用途土地并最终汇入波斯湾的主要水体——阿尔万德河（伊朗）中的微塑料（MPs）进行了调查。这是首次对阿尔万德河的 MP 污染（污染程度和理化特征）进行评估，涵盖了河流中的沉积物和水体。在位于河流沿线的 24 个站点进行了 MPs 监测。结果表明，在水中和沉积物中，MP 污染的范围分别为 1 至 291 个/升和 70 至 15620 个/千克（干重）。大部分 MPs 为纤维状，颜色为黑色/灰色和黄色/橙色，尺寸主要为 250-500 μm 和＞1000 μm。在沉积物样本中发现了聚对苯二甲酸乙二醇酯（PET）、聚丙烯（PP）、尼龙（NYL）、高密度聚乙烯（HDPE）和聚苯乙烯（PS）。除了 HDPE 之外，这些聚合物在水样中也有发现。PET 和 PP 在水样中占主导地位，而 PET 和 PS 在沉积物中最为丰富。城市废水排放可能是造成水体和沉积物中 MP 污染的原因。与未受干扰的自然区域相比，在城市地区，不同土地利用方式对 MP 浓度的影响存在显著差异（p＜0.05）。通过 PCA 双标图分析发现，水中的 MPs 纤维和碎片具有相似的分布，它们之间存在显著相关性。在沉积物样本中，纤维和碎片状 MPs 颗粒与胶体颗粒（如粘土和有机物）显著相关，这表明胶体颗粒在阿尔万德河的水生态系统中对 MPs 的传输具有重要作用。本研究有助于更好地了解主要河流中 MPs 的存在情况，因为这些系统对这种类型的污染的研究较少，可为减少 MP 输入河流和海洋的干预措施提供信息。
