HA1絮凝剂在供水水库水华应急处理中的应用研究

Usage of Flocculation in Emergent Control of Algal Bloom in Drinking Water Supplying Reservoir

2006-04华南一座供水水库发生卷曲鱼腥藻（Anabaena circinalis）水华,供水口形成藻细胞的堆积,浮游植物、蓝藻、卷曲鱼腥藻（Anabaena circinalis）的细胞密度分别高达7.3×10^7、7.2×10^7、4.1×10^7 cells·L^-1.为保障正常供水,于04-22～04-30用小孔径的网和防水膜对供水口进行区域分隔,改变水流方向,同时在水面喷射以铁盐为核心的HA1絮凝剂控制水华.处理第1 d,浮游植物、蓝藻、卷曲鱼腥藻（Anabaena circinalis）的细胞密度分别降至5.3×10^6、4.7×10^6、2×10^6 cells·L^-1,去除率分别达到93%、94%和95%.处理期间,藻细胞密度平均为1.2×10^7 cells·L^-1,最高不超过2.0×10^7 cells·L^-1,不同藻类门的处理效果不同,蓝藻的数量大幅度下降,绿藻、硅藻的种类和数量略有增加,说明HA1絮凝剂在本次应急处理方案中对蓝藻具有较好的去除效果.

An Anabaena circinalis bloom appeared in a reservoir for supplying drinking water in the south of China, in April 2006. Phytoplankton scums gathered and floated on the surface of the whole reservoir especially on the area of water intake, and the cell density of phytoplankton, cyanobacteria and Anabaena circinalis was as high as 7.3 × 107, 7.2 × 107, 4.1 × 107 cells·L^-1 respectively. To maintain drinking water supplying, an emergency program was initiated to control the cyanobacterial bloom. The zone immediately adjacent to the water intake was divided into two small zones by fishing nets and waterproof curtains to modify the water flow. Iron-based flocculants were then applied to control the algal bloom. As a result, the density of the phytoplankton decreased greatly, and at the first day the cell densities of phytoplankton, cyanobacterial, Anabaena circinalis decreased to 5.3 ×106 ,4.7 ×106, 2 × 106 cells·L^-1 respectively, and the removal of them reached up to 93 %, 94 %, 95 % respectively. The average of phytoplankton cell density was 1.2 × 107 cells·L^-1 and a highest density was 2.0 ×107 cells·L^-1 during the treatment from 22 to 30 April, while Chlorophyta and Bacillariophyta slightly increased. These encouraging results suggest that the flocculants used are efficient at removing Cyanobacteria.