Eutrophication - Eutrophication

Generally, this refers to the phenomenon in which nutrients such as nitrogen and phosphorus increase in bodies of water such as the sea and lakes. When this phenomenon occurs in the sea, it can cause red tides, and in lakes and ponds, phytoplankton and algae such as blue-green algae grow abnormally, which results in the lower layers of the water becoming anaerobic, causing the death of fish and shellfish, and causing damage such as odors in drinking water due to the generation of _N2 , _H2S , and methane. Furthermore, when such water is used as a source of tap water, the amount of trihalomethanes generated during the water purification process increases, which is a problem along with water pollution. Much of this eutrophication is caused primarily by human factors such as domestic wastewater, industrial wastewater, and agricultural wastewater. Another major source of load is the return of some of the nitrogen compounds released into the atmosphere by the burning of fossil fuels and the incineration of garbage to surface water bodies via rainwater. It is hoped that tertiary treatment of wastewater will be fully implemented to prevent eutrophication of water bodies.

Source: Morikita Publishing "Chemical Dictionary (2nd Edition)" Information about the Chemical Dictionary 2nd Edition

一般に，海，湖沼などの水域において，窒素，リンなどの栄養塩類が増加する現象をいう．海域でこの現象が起こると赤潮の発生の原因になり，湖沼では植物プランクトンやアオコなどの藻類が異常に増殖し，その結果として，低層水中が嫌気性となり，魚貝類の斃(へい)死，さらに，N₂，H₂S，メタンなどの発生による上水の着臭などの被害が起こる．また，このような水を水道水源とした場合，浄水処理工程でのトリハロメタンの発生量が増加することにもなり，水質汚濁とともに問題となっている．こうした富栄養化の多くは，生活排水，工場排水，農業排水などの人為的なものが主要因となって進行する．化石燃料の燃焼，ごみ焼却によって大気中に放出された窒素化合物の一部が，雨水によって地表の水域に戻されることも，主要負荷源の一つとして注目されている．排水処理の三次処理を完全に実施し，水域の富栄養化防止を実現することが望まれている．

出典　森北出版「化学辞典（第2版）」化学辞典 第2版について　情報