Abundance and Characteristics of Microplastics in the Martapura River, Banjarmasin, South Kalimantan

Abstract

The Martapura River serves as a vital resource for local communities in Banjarmasin, South Kalimantan, functioning as a means of transportation, for domestic, tourism, and as a source of drinking water. However, the environment is experiencing pollution from various human activities, with microplastic contamination being a significant concern. The presence of microplastic particles in the waters can have negative impacts on aquatic organisms and pose health issues such as digestive problems, toxicity, immune dysfunction, and reproductive disorders. The purpose of this study is to investigate the abundance and characteristics of microplastics in the Martapura River in Banjarmasin, South Kalimantan. Water sampling was conducted at 10 locations, following the SNI 8995:2021 standard, and considering environmental conditions. Water sample preparation was carried out by adding 10% KOH, followed by microplastic density separation using saturated NaCl in a 3:1 ratio. A 20 mL supernatant solution was collected for observation using a Sedgewick Rafter Counting Cell and a binocular microscope. Based on the analysis of the 10 sampling points in the Martapura River, the abundance of microplastics ranged from 3,000 to 16,000 particles/L, with the following characteristics: fragments (29.90%), fibers (20.62%), pellets (26.80%), and films (22.68%). The highest abundance of microplastics was found in the Pasar Lama subdistrict and Basirih subdistrict, with 16,000 particles/L and 14,000 particles/L, where the most dominant type was fragment microplastics, accounting for 29.90%.