遮光法控藻的中试研究

Pilot-scale alga control by light shading

进行了遮光法控制富营养化水池中藻类的中试研究.结果显示,9d试验后,叶绿素a浓度、COD、浊度、DO分别由遮光前的130.5μg·L-1、30.9mg·L-1、20.0NTU、12.0mg·L-1下降至处理后的24.8μg·L-1、1.7mg·L-1、5.4NTU、3.1mg·L-1,TP、TN浓度则变化不明显.表明遮光处理能够在营养盐浓度变化不大的状况下大幅度削减藻类生物量;遮光1d后,105cm处的叶绿素a浓度、COD、浊度都较水面表层浓度高,显示遮光之后藻类出现了沉降的现象;遮光2d后,水深30cm以下的净生产量都为负值,显示遮光显著抑制了藻类的光合产氧速率,并促使藻类消亡.

A pilot-scale experiment of alga control by light shading was conducted in a eutrophicated pond. The results showed that light shading could greatly reduce the alga biomass without removing nutrients after 9 days, considering that Chla declined from 130.5 μg·L^-1 to 24.8μg·L^-1; COD from 30.9 mg·L^-1to 1.7mg·L^-1; turbidity from 20.0 NTU to 5.4 NTU and DO from 12.0 mg·L^-1 to 3.1 mg·L^-1; but TP and TN did not vary significantly. After light shading for 1 day, Chla, COD and turbidity 105 cm beneath the water were higher than at the water surface, showing that alga was likely to sediment after light shading. After light shading for 2 days, the net productivity 30cm beneath the water was negative, suggesting that the photosynthetic rate was inhibited, which induced algal death.