ABUNDANCE AND COMPOSITION OF RIVERBANK MACROPLASTICS IN HAMADA RIVER, TOYOHASHI, JAPAN

Abstract

Plastic is consumed by many people because it is more economical, lightweight, and durable. World plastic production is estimated at 322 million tons. Plastics are used in almost every aspect of life from packaging to construction, automotive, electronics, clothing, and agriculture.. Plastic waste is divided into several categories, namely macroplastic >25 mm, mesoplastic 5-25 mm, and microplastic <5 mm. This study was conducted on a tributary of the Umeda River, namely the Hamada River. The Umeda River flows into Mikawa Bay through Toyohashi City in Aichi Prefecture, Japan. Samples were taken from plots measuring 10x2.5m on the riverbank for the downstream and 10x0.5m for the upstream. Visually identifiable plastic waste is collected by hand. The coordinates of plastic waste locations are recorded to determine the distribution of plastic waste at the sampling location. The tools used in this study were flowmeters, nets, roller meters, trash bags, cameras, and stationery. Trash trapping method is used to collect macroplastic waste in river water. The net as a trash trap is placed vertically above the water body for six hours. The most macroplastic waste was found in the upstream of the Hamada River is 4.8 items/m2 , while in the downstream of the Hamada River is 2.64 items/m2. Based on the observations, there were six types of polymers identified, namely polyethylene, cardboard, kerosene, wood, dioctylplathalate, and polyurethane foam. The most common type of polymer found downstream and upstream of the Hamada River is polyethylene with a percentage of 87% downstream and 73% upstream. There are several types of Polyethylene polymers, namely polyethylene terephthalate (PET), high density polyethylene (HDPE), and low density polyethylene (LDPE). he flow of water that flows regularly from upstream to downstream can also cause macroplastic waste to be carried away and stuck in tree branches so that a lot of macroplastic waste is found upstream. Unknown plastic is the largest part of all macroplastic waste collected. The second most macroplastic waste is rope plastic and followed by mulch plastic. This is because the sampling location is close to the tabaco plantation area during spring and cabbage during summer. The composition of the most macroplastic waste found was polyethylene.