Evaluation of the performance of Tehran drinking water treatment plants in removing nanoplastics and microplastics

Abstract

Background and Objective: Microplastics can have harmful effects on living things, including humans. These particles have been identified in all water, soil, and food sources. Among these, freshwater resources are more important, because they are considered a water source for humans through drinking water treatment plants (DWTPs). Therefore, this study investigates the performance of Tehran DWTPs in removing these particles. Materials and Methods: In this study, the performance of three DWTPs in Tehran in removing these particles was investigated. In most studies worldwide, particles larger than 1 µm were examined, but in this study, nanoplastic particles smaller than 1 µm, as well as the effect of the warm and cold seasons of the year on the concentration of these particles were also examined. Results: According to the results of the study, the amount of micro and nanoplastic particles at the inlet of treatment plants in the warm season of the year was 2569 ± 309 to 3918 ± 425 MP/L, and the output was 1492 ± 32 to 2279 ± 146 MP/L, which indicates an increase in these particles in the warm season. As a result, the studied treatment plants were only able to remove 32.1 to 59.9% of these particles. In addition, using electron microscopy, MPs were classified into three categories in terms of appearance: fiber, fragment, and film. This study completes the knowledge of MPs in this area. Conclusion: Based on the results of this study, Tehran DWTPs have poor performance in removing these particles.

Keywords

• microplastic
• nanoplastic
• water pollution
• drinking water treatment plant
• scanning electron microscope