浅水湖泊防控黑臭水体复氧技术
Re-oxygenation technology for prevention and control of black water in shallow lakes

试验研究了复氧技术防控浅水湖泊黑臭水体发生的机理和复氧设备.研究发现,当太湖水在藻浓度1.0×108~5.0 ×108 cells/L,水温约28 ℃时,静止过程中水中的CODMn、二甲基三硫醚浓度持续升高,6 d后发生明显的类湖泛的水体黑臭现象,表明采用人工复氧维持水中1.0 mg/L溶解氧的方法可防控藻源性局部黑臭水体发生.研发出3种升流循环复氧装置,结果显示,Ⅲ型装置充氧及能量利用率性能最佳.中试试验显示,Ⅲ型中试溶解氧升高及扩散趋势与fluent模型相符,80 h时溶解氧平均值为3.65 mg/ L,溶解氧平均上升速率为0.045 4 mg/(L？h);升流循环复氧机在模拟黑臭水体应急处置时, 48 h时影响半径可达到50 m.初步证明升流循环复氧装置可作为应急充氧设备, 用于类似太湖的浅水湖泊黑臭水体的治理领域.
The mechanism of re-oxygenation technology to control black water aggregation(BWA)in a shallow lake was explored. Static experiments show that under a temperature of 28 ℃ and the blue algae density of 1.0×108 to 5.0 ×108 cells/L, the concentration of CODMn, dimethyl trisulfide( DMTS )in Taihu Lake continually rises,and finally becomes black and putrid after 6 d. It shows that artificial aeration to maintain dissolved oxygen(DO)content exceeding 1.0 mg/L in water can prevent and control the occurrence of black and putrid water.Three types of up-flowing cycle re-oxygenation(UFCR)devices for shallow lake oxygenation are developed, and type Ⅲ is optimal. The simulated black water pilot test shows that the diffusion trend of the DO for the type Ⅲ device is consistent with the corresponding fluent software model. After 80 h,the concentration of DO is 3.65 mg/L,and the average rising rate is 0.045 4 mg/(L？h). The influence radius of type Ⅲ device can reach 50 m after 48 h when the UFCR is used to treat black and putrid water. This device can be used to prevent and control the emergence of black and putrid water in shallow lakes