OCCURENCE OF MICROPLASTICS AND ESTIMATION OF SOURCES TO RIVER WATER IN KATHMANDU CITY, NEPAL
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- OKAMOTO Moemi
- 京都大学 大学院工学研究科
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- TANAKA Shuhei
- 京都大学 大学院地球環境学堂
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- YUKIOKA Satoru
- 京都大学 大学院地球環境学舎
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- FUJII Shigeo
- 京都大学 大学院地球環境学堂
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- SINGH Sangeeta
- Tribhuvan Univ. Department of Architecture and Urban Planning
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- TAKADA Hideshige
- 東京農工大学 農学部
Bibliographic Information
- Other Title
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- ネパール国カトマンズ市におけるマイクロプラスチックの存在実態の把握および河川への負荷源の推定
- ネパールコク カトマンズシ ニ オケル マイクロプラスチック ノ ソンザイ ジッタイ ノ ハアク オヨビ カセン エ ノ フカ ゲン ノ スイテイ
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Description
<p> Recently, microplastics (MPs) have been getting attention worldwide due to its potential for environmental impacts. However, one of the challenges of MPs studies is the comparison of various studies is difficult because there is no authorized method for measuring MPs. It is important to understand the characteristics and sources of MPs pollution in each region in order to reduce the load of MPs. In this study, we reported that the occurrence of MPs in road dust and river surface water in Kathmandu city, Nepal as an example of developing countries in Asia. In addition, we compared these results with that in Da Nang City (Vietnam) and Kusatsu City (Japan), which were conducted in the same way by authors. The results showed that the average MPs concentrations were 25.7~339 pieces/m2 (n=4) in road dust and 600~45, 600 pieces/m3 (n=5) in river surface water (Bagmati River and Bisunumati River). In terms of composition, polyethylene and rubber plastics accounted for 40 % and 18 % of all MPs in road dust, while 70 % of MPs in river surface water were detected as acrylic plastics. The average sizes of MPs were significantly larger (p<0.01) in river surface water (median: 432 μm) than those in road dust (median: 309 μm). As a result, it was suspected that one of the main sources of MPs in river surface water in Kathmandu City is untreated wastewater. Therefore, it was expected that MPs concentrations would decrease after completion of wastewater treatment plant construction.</p>
Journal
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- Journal of Japan Society of Civil Engineers, Ser. G (Environmental Research)
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Journal of Japan Society of Civil Engineers, Ser. G (Environmental Research) 75 (7), III_127-III_134, 2019
Japan Society of Civil Engineers