曝气和阿科蔓填料对月湖围隔中的水质改善作用

Improvement of Water Quality of Yuehu Lake Using Aeration Assisted by AquaMats

在重富营养化的武汉月湖建立围隔,研究了曝气和投放阿科蔓填料对水质的改善作用。结果表明:建立围隔(5m×5m)后,会使内外水的TP浓度产生明显差异,发生水华的程度和频率增加,进而对透明度(SD)、Chla和COD造成负面影响;水下曝气、放置水花生浮床能够减轻水华发生的频率和程度。经13个月的曝气(每天2~3小时),能够明显降低水中的TN浓度,对TP和COD没有明显影响,在有水华时,能够通过抑制水华而降低Chla,提高SD;在没有水华时,对Chla和SD无明显影响。经11个月的围隔实验,投放阿科蔓(每个围隔2m)2能够能够降低COD和Chla浓度,提高SD,但对TN、TP浓度没有明显影响。

In situ experiment for lake recovery was carried out with an array of enclosures (5m×5m)set up in Yuehu Lake,a shallow hypereutrophic lake in Wuhan City.Aeration devices were used within each of the enclosures plus floating plant beds with Alternanthera philoxeroides to control algal bloom,and aeration of 13 consecutive months (2~3h/d)led to an apparent decrease of TN concentration.However,no measurable changes of TP and COD were observed.Aeration could abate algal bloom and improve lake water transparency during the outbreak of algal bloom,but it seemed that aeration alone had no effects on lake water improvement in terms of Chl-a and SD levels during the seasons with no algal bloom.Then AquaMats,a patented product characterized by highly specialized synthetic substrates introduced from the US was applied (2m2 in each enclosure)for the enhancement.Through 11 consecutive months of experiment,it was showed that Chl-a and COD concentration had been depressed and SD increased,but TN and TP had barely been changed.