The mechanism and rate of re-sedimentation of phosphorus released from the sediment during the summer months in shallow brackish lakes

DOI JASI Web Site Web Site 18 References
  • KAMIYA Hiroshi
    Shimane Prefectural Institute of Public Health and Environmental Science
  • SUGAHARA Shogo
    Department of Material Science, Faculty of Science and Engineering, Shimane University
  • SAGA Yuki
    Shimane Prefectural Institute of Public Health and Environmental Science
  • SATO Sachiko
    Shimane Prefectural Institute of Public Health and Environmental Science
  • NOJIRI Yukari
    Shimane Prefectural Institute of Public Health and Environmental Science
  • KISHI Masashi
    Shimane Prefectural Institute of Public Health and Environmental Science
  • FUJIHARA Atsuo
    Shimane Prefectural Institute of Public Health and Environmental Science
  • GODO Toshiyuki
    Shimane Prefectural Institute of Public Health and Environmental Science

Bibliographic Information

Other Title
  • 浅い汽水湖沼における夏季に堆積物から溶出したリンの湖底への再沈降割合とその機構
  • アサイ キスイ コショウ ニ オケル カキ ニ タイセキブツ カラ トケダシタ リン ノ コテイ エ ノ サイチンコウ ワリアイ ト ソノ キコウ

Search this article

Abstract

Water, salt and phosphorus balance of the 19 years was calculated in Lake Shinji, a shallow brackish lake in Japan. Average annual freshwater inflow of 19 years into Lake Shinji was in the range of the 1.25 ～ 2.35 × 109m3, the average was 1.77 × 109m3. Reverse flow from the Lake Nakaumi located downstream of the Lake Shinji was in the range of 0.32 ～ 0.84 × 109m3, the average was 0.49 × 109m3, corresponding to 27.7% of the freshwater inflow. Retention time in consideration of the amount of freshwater inflow and reverse flow from the Lake Nakaumi were from 47.5 to 76.2 days, and 59.4 days on average. The percentage of annual deposition of TP to inflow TP was in the range of -23.6 to 69.3%, and 20.9% on average. In addition, there was a positive relationship (r = 0.71) between annual TP inflow and sedimentation rate, settlement amount was small drought year when inflow is low.<br>　Phosphorus concentrations peaked by released from the sediment in August-September around becomes a normal value almost in November-December. We calculated the ratio of phosphorus resettle to the sediment for the duration from the peak of the TP stock to become normal value, using water amount of outflow from Lake Shinji, inflow load and TP concentration of Lake Shinji. TP sedimentation rate was in the range of 8.8 to 65.6%, and 45.1% of phosphorus which released in summer was resettled to the bottom of the lake again in average, and it was considered to be involved in the release of the following year.<br>　In the process of phosphorus concentration decreases, SRP was greatly reduced, but the fact that changes in the PP was hardly seen. The SRP reduction occur when DO at the sediment surface increased at the same time. It was considered that reduction of phosphorus in the water column that released from sediment when there was anoxic is attributed to the SRP adsorption to the sediment surface where become aerobic. At this time sediment is deficiency state of phosphorus because it is after releasing SRP, it was believed to adsorb SRP easily.

Journal

References(18)*help

See more

Keywords

Details 詳細情報について

Report a problem

Back to top