Microplastic Pollution in the Sangu River, Bangladesh: Occurrence, Abundance and Physicochemical Features

Abstract

Microplastics (MPs) have been found in aquatic ecosystems as a result of the widespread non-biodegradable trash generated by the varied usage of numerous synthetic polymers, mostly plastics. Bangladesh is among the nations where microplastic pollution may pose a threat. Very little research has been done on the microplastic pollution occurring in the study areas of the Sangu River. Those locations were chosen as the study areas for this reason. This study aimed to determine MP abundance and variation as well as MP properties in the Sangu River study sites. Sampling was conducted from February 2023 to June 2023. According to the results, the mean concentration of microplastics in the samples collected from Chandanaish was 5496.11 ± 3089.777 items/100 m3, but the samples collected from Juidondi had a mean concentration of 6550.22 ± 4046.614 items/100 m3. The findings indicated that elongated (45%) and angular (28%) were more dominant over irregular shapes (15%) and rectangular shapes (12%). Additionally, the presence of microplastics (MPs) such as films (13.5%), and small amounts of foam (10.5%) and granules (8%) was overshadowed by fragments (28%) and filaments (40%). Moreover, four size groups were created from the identified MPs, with the 100 μm to < 500 μm category (54.43%) and the 500 μm to < 1000 μm category (29.11%) being the most dominant, followed by the 1000 μm to < 2mm category (11.39%), and the 2mm to < 3mm category (5.07%). In this study, four distinct groups of microplastic color were identified. Black microplastics accounted for 61.45% of the total, followed by red at 21.69%, green at 3.61%, and transparent at 13.25%. Quantifying and identifying MPs using a single method is quite challenging. It is recommended to use modern and standard method while sampling of MPs and further research studies are needed badly.