Identification of nitrogen contamination mechanisms of groundwater in coastal areas of Central Vietnam by using microbial technologies and stable isotope analyses

2017 Fiscal Year Final Research Report

• Project/Area Number: 15H05255
• Research Category: Grant-in-Aid for Scientific Research (B)
• Allocation Type: Single-year Grants
• Section: 海外学術
• Research Field: Rural environmental engineering/Planning
• Research Institution: Okayama University
• Principal Investigator: Maeda Morihiro 岡山大学, 環境生命科学研究科, 教授 (00355546)
• Co-Investigator(Kenkyū-buntansha): 近森 秀高 岡山大学, 環境生命科学研究科, 教授 (40217229) ; 井上 大介 大阪大学, 工学研究科, 准教授 (70448091)
• Research Collaborator: Nguyen Duc Huy フエ大学, バイオテクノロジー研究所, 副所長 ; Le Van Thang フエ科学大学, 准教授 ; Hoang Ngoc Tuong Van フエ大学, 環境資源研究所, 研究員
• Project Period (FY): 2015-04-01 – 2018-03-31
• Keywords: 窒素 / 地下水汚染 / 安定同位体比 / 国際情報交換 / 微生物機能

Outline of Final Research Achievements

In the downstream agricultural areas of Central Vietnam, high concentrations of NH4-N and NO3-N were found in groundwater. Results of 15N natural abundance of different nitrogen forms indicated that the groundwater contamination was attributed to unintended inflow of livestock wastes and/or domestic wastewater. Soil functional genes related to the nitrogen cycle were largely different between farms and dry/rainy seasons and were not clearly linked to the groundwater contamination, suggesting that the composition of nitrogen-cycling genes does not directly have a significant influence on the groundwater contamination. Moreover, we developed an integrated water and material circulation model composed of rainfall-runoff, unsteady river flow and groundwater models for analyzing the nitrogen dynamics in groundwater of the study areas.

Free Research Field

地域環境工学，土壌肥料学