(419c) Stack Emission of Microplastics from Municipal Solid Waste Incineration Power Plants and Its Characteristics

Incineration has been widely used for municipal solid waste (MSW) disposal. Generally, organic components in MSW are subject to be completely thermal decomposed in the incineration process, however, recent studies revealed that incineration fails to eliminate microplastics. As a new class of pollutant, microplastics is considered to have a harmful impact on the environments. Therefore, it is important to knowledge the emissions and characteristics of microplastics from MSW power plants.

In this work, circulating fluidized bed MSW incinerators were chosen for field testing. U. S. EPA Method 5 was adopted for collecting the particles in flue gas stream. The microplastics were identified and quantified by the means of the combination techniques of micro-Raman, scanning electron microscope (SEM)-energy dispersive X-ray detector (EDX) and laser direct infrared (LD-IR). Moreover, the effects of existing air pollution control devices (APCDs) on microplastics removal were evaluated.

Based on the field testing data, it is found out that the microplastics emissions from the tested incinerator stack is around 2.5×10³ pieces/m³, which is much higher than the reported microplastic abundances in general atmospheric environments. The predominant length of the microplastics in the flue gas ranged from 10 to 40 μm. The microplastics with width < 10 μm accounted for ~71% in the chimney. The major polymer types of microplastics were polyvinyl chloride and polyacrylamide. Fabric filter exhibited more effective performance for microplastics removal than other APCDs. This work is the first attempt to study the microplastic emission from MSW incineration power plants, a commonly overlooked source of atmospheric microplastics.