有效微生物群控制富营养化湖泊蓝藻的效应

Control of Algae Bloom in Eutrophic Water by Effective Microorganisms

在藻型富营养化的湖泊水体中应用有效微生物群菌剂的结果表明,有效微生物群对水体的透明度、叶绿素a含量的改善有明显的效果,可有效抑制藻类的生长,防止水华的发生,改善景观.在投入有效微生物群后,透明度迅速提高,2个月后,透明度提高了433%;水体表面的叶绿素a含量在1个月后下降了965%并维持在1379mg/m3以下;水深05m处的叶绿素a含量在投放菌剂期间及之后1个月保持在100mg/m3以下;在投放菌剂后溶解氧有暂时的下降,较本底值772mg/L下降了258%,但很快持续上升至1299mg/L;生化需氧量在投放菌剂期间及之后1个月变化不大,仅上升39%;停止投放菌剂后1个月左右,总N、总P含量和高锰酸盐指数均下降至最低点,分别下降了60.2%,58.1%和57.2%.停止使用有效微生物群约1个半月后,试验区的透明度、总N、总P、高锰酸盐指数(CODMn)和生化需氧量均有反弹现象,但一直未见“水华”发生.

Effects of effective microorganisms(simplified as EM) on control of algae bloom in eutrophic water were studied in a small lake in South China Botanic Garden of Chinese Science Academy where algae bloom frequently occurred The results showed that content of Chl a both on the water surface and 0 5 m below the water surface,total N and P, and COD Mn decreased after the spraying of EM, while the content of DO and water transparency increased accordingly The very remarkable decrement of Chl a on water surface indicated that the algae bloom had been completely controlled, and it contributed directly to the increase of the water transparency The decrements of the content of total N and P, and organic matter seemed to be the main factors which caused the decreasing of algae However, it is difficult to explain why the BOD 5 increased The period that EM keeps active in controlling algae is estimated to be about one and half a month