Abstract：
Urban stormwater runoff has been suggested as one important land-based pathway of microplastics (MPs) entering the oceans, in which the abundance and characteristics of MPs may be influenced by urban land use types. However, little information has been reported regarding this, especially in the tropical monsoon region. This study first reports the MPs in urban stormwater runoffs in a tropical monsoon region that were collected from four typical urban land use types, including industrial, highways, commercial, and residential areas. The average MP particle count and mass concentration were measured as 4.7 ± 3.5 particles/L and 3.8 ± 2.9 mg/L, respectively. MP abundances showed clear urban land use gradients following the order of industrial > transportation > commercial > residential area. In terms of the seasonal variation in MP abundances, a slightly increasing particle count in the dry season was noted for the residential site. Source apportionment of MPs in stormwater runoffs was demonstrated based on the land use type, particle morphology, and chemical compositions. With the simple apportionment approach, approximately 85% of the MP sources were able to be identified in the industrial, transportation, and residential sites. However, the commercial site showed high variability in terms of the morphology and polymer type of MPs. Furthermore, significantly positive correlations between MP abundance and runoff turbidity, TSS, COD, and rainfall intensity were identified, while, no significant correlation was found between MP characteristics and selected water quality/meteorological parameters.
摘要：
城市雨水径流已被认为是微塑料（MP）进入海洋的重要陆基途径之一，其中MPs的丰度和特征可能受到城市土地利用类型的影响。然而,这方面的报道很少，尤其是在热带季风区.这项研究首先报告了热带季风区城市雨水径流中的MP，这些MP是从四种典型的城市土地利用类型中收集的，包括工业区，高速公路,商业区,和住宅区。平均MP颗粒计数和质量浓度分别为4.7±3.5颗粒/L和3.8±2.9mg/L。分别。MP丰度显示出明显的城市土地利用梯度，遵循工业>交通>商业>住宅区的顺序。就MP丰度的季节性变化而言，在旱季，住宅区的浓度略有增加。根据土地利用类型证明了雨水径流中MP的来源分配，颗粒形态，和化学成分。通过简单的分摊方法，大约85%的MP来源能够在工业中被识别，交通运输,和住宅网站。然而,商业站点在MPs的形态和聚合物类型方面表现出很高的变异性。此外，MP丰度与径流浊度显著正相关，TSS,COD,COD并确定了降雨强度，而MP特征与选定的水质/气象参数之间没有发现显着相关性。
