College of Marine Science and Technology, China University of Geosciences (Wuhan), Lumo Road 388, Wuhan, 430074, China; Third Institute of Oceanography, Ministry of Natural Resources, Daxue Road 178, Xiamen, 361005, China.
Third Institute of Oceanography, Ministry of Natural Resources, Daxue Road 178, Xiamen, 361005, China.
Water Res. 2019 May 15;155:255-265. doi: 10.1016/j.watres.2019.02.028. Epub 2019 Feb 25.
Studying the abundance, characteristics, and removal of microplastics (MPs) in wastewater treatment plants (WWTPs) in coastal cities is of great significance for understanding the impacts of human activities on the marine environment, but currently, little information on this topic is available in China. Therefore, the abundance, characteristics, and removal of MPs in seven WWTPs of Xiamen, a typical coastal city in China, are studied. Sixty samples were collected using an improved sampling method involving an electromagnetic flowmeter and a fast digital camera. The influent MPs concentration is 1.57-13.69 items/L, and it is reduced to 0.20-1.73 items/L in the effluent, indicating that 79.3-97.8% MPs is removed. Based on the daily effluent discharge and MPs removal rate, it is estimated that ∼6.5 × 10 MPs are released from the seven WWTPs into the Xiamen Bay each day. The light microscopic and micro-Raman spectroscopic analysis indicates that ∼62.68% of particles are plastic polymers, including polypropylene (31.6%), polyethylene (21.9%), polystyrene (10.1%), propylene/ethylene copolymer (9.2%), and polyethylene terephthalate (7.5%). The color of MPs is mainly composed of white (27.3%) and clears (25.8%). Our results show that granules (41.1%) are the dominant shape of MPs, followed by fragments (31.3%), fibers (23.7%), and pellet (3.9%). The characteristics of MPs such as sizes, shapes, and types affect the MPs removal in WWTPs. Our findings show that MPs concentration in the influent is positively correlated with the suspended solids (SS), however, in the effluent, it is associated with the WWTPs operating load, as reflected by obviously higher MP abundance in overloaded ones.
研究沿海城市污水处理厂（WWTP）中微塑料（MPs）的丰度、特征和去除率对于了解人类活动对海洋环境的影响具有重要意义，但目前中国在这一领域的信息很少。因此，本研究对中国典型沿海城市厦门的 7 个 WWTP 中的 MPs 丰度、特征和去除率进行了研究。采用改进的采样方法，利用电磁流量计和快速数码相机采集了 60 个水样。进水 MPs 浓度为 1.57-13.69 个/L，出水中 MPs 浓度降低至 0.20-1.73 个/L，表明 79.3-97.8%的 MPs 被去除。根据每日出流水量和 MPs 去除率估算，每天约有 6.5×10⁶个 MPs 从这 7 个 WWTP 释放到厦门湾。基于光学显微镜和微拉曼光谱分析，约 62.68%的颗粒为塑料聚合物，包括聚丙烯（31.6%）、聚乙烯（21.9%）、聚苯乙烯（10.1%）、丙烯/乙烯共聚物（9.2%）和聚对苯二甲酸乙二醇酯（7.5%）。MPs 的颜色主要由白色（27.3%）和透明色（25.8%）组成。结果表明，颗粒（41.1%）是 MPs 的主要形态，其次是碎片（31.3%）、纤维（23.7%）和小球（3.9%）。MPs 的尺寸、形状和类型等特征会影响 WWTP 中的 MPs 去除率。研究结果表明，进水 MPs 浓度与悬浮物（SS）呈正相关，但在出水中，其与 WWTP 的运行负荷有关，负荷过高的 WWTP 中 MPs 丰度明显更高。
