Ammonia distribution and ecological risk assessment in nine fresh lakes in China.

With the development of industry and economy, ammonia nitrogen pollutions in surface water are of great concern worldwide. This study investigated the historical contents of total ammonia nitrogen (TAN) and unionized ammonia molecules (NH) in nine fresh lakes in China during 2014-2022. Three different classification methods (flood season, season, and geographical distribution) were used to analyze the concentration variation of TAN and NH.