Valizadeh Behzad, Abdoli Mohammad Ali, Mahmoudkhani Rouhalla, Abdossalami Asl Yousef
Department of Environmental Engineering, Faculty of Environment, University of Tehran, Tehran, Iran.
Department of Environmental Engineering, Science and Research Branch, Islamic Azad University, Tehran, Iran.
Sci Rep. 2025 Aug 7;15(1):28973. doi: 10.1038/s41598-025-93155-6.
Despite the advantages of Municipal Solid Waste (MSW) incinerators, including reducing landfilling and producing energy, the production of ash is a serious concerns, beside the emission of polluting gases. In this study, the quantity and characteristics of microplastics in the ash of active incinerators in Iran were investigated. For this purpose, sampling was done for one year and the microplastics in the ash were observed and analyzed by sophisticated laboratory equipment. The samples were dried at 65 ºC and sieved using a sieve with a pore diameter of 1.0 mm. NaCl saturated solution was used for microplastic extraction in flotation process. The abundance and characteristics of microplastics in each sample were analyzed using microscope and stereomicroscope. The results showed that in all ash samples, there were microplastics of different sizes, and in total, 65.3% of them were less than 10 µm in size. The number of microplastics in the samples of Tehran and Nowshahr incinerators varied from 104 to 212 and 68 to 193 per 100 g of samples, respectively. Raman spectroscopy results showed that the origin of most microplastic particles is related to polyvinyl chloride (35%) and polypropylene (22%). Blue was the dominant color of microplastics (41% in Tehran samples and 40.5% in Nowshahr samples) and green was the least frequent color of microplastics (5.4% in Tehran samples and 6.4% in Nowshahr samples). Elemental analysis results by Scanning electron microscopy (SEM) and energy dispersive X-ray spectroscopy (EDS) also showed high percentage of metals including iron, manganese, and calcium, along with carbon, sodium and chlorine on the surface of the microplastic samples. Considering the environmental health concerns of microplastics, it can be inferred that MSW incinerators cannot terminate the emerging pollutant, namely microplastics, and necessary consideration requires to reduce the volume of plastics in the waste and incorporating environmental friendly measures to prevent releasing these pollutants into the environment.
尽管城市固体废物（MSW）焚烧炉具有诸多优点，包括减少填埋量和产生能源，但除了污染气体排放外，灰渣的产生也是一个严重问题。在本研究中，对伊朗现役焚烧炉灰渣中的微塑料数量和特性进行了调查。为此，进行了为期一年的采样，并使用先进的实验室设备对灰渣中的微塑料进行了观察和分析。样品在65℃下干燥，并用孔径为1.0毫米的筛子进行筛分。在浮选过程中使用氯化钠饱和溶液提取微塑料。使用显微镜和体视显微镜分析每个样品中微塑料的丰度和特性。结果表明，在所有灰渣样品中，都存在不同尺寸的微塑料，其中65.3%的微塑料尺寸小于10微米。德黑兰和诺沙赫尔焚烧炉样品中每100克样品的微塑料数量分别在104至212个和68至193个之间。拉曼光谱结果表明，大多数微塑料颗粒的来源与聚氯乙烯（35%）和聚丙烯（22%）有关。蓝色是微塑料的主要颜色（德黑兰样品中为41%，诺沙赫尔样品中为40.5%），绿色是微塑料中出现频率最低的颜色（德黑兰样品中为5.4%，诺沙赫尔样品中为6.4%）。扫描电子显微镜（SEM）和能量色散X射线光谱（EDS）的元素分析结果还表明，微塑料样品表面除了碳、钠和氯外，还含有高比例的金属，包括铁、锰和钙。考虑到微塑料对环境健康的影响，可以推断城市固体废物焚烧炉无法消除新出现的污染物——微塑料，因此需要采取必要措施减少垃圾中塑料的体积，并采取环保措施防止这些污染物释放到环境中。
