微气泡水力空化强化混凝除藻的试验研究

Microbubble Hydrodynamic Cavitation-Enhanced Coagulation for Algae Removal

利用微气泡水力空化装置强化混凝沉淀去除水体中的藻类。结果表明，微气泡水力空化可以有效地提高混凝除藻效果，减少混凝剂用量。当混凝剂投加量为1mg／L时，水力空化预处理5min，对藻类的去除率较空白样提高13％，而空化预处理20min则藻类去除率提高30％。对藻类的去除率均为65％时，1h的水力空化可以减少50％的混凝剂投加量。微气泡水力空化时间和空气流量对强化混凝效果有很大的影响，在空化处理时间为10～20min、空气流量为O．5—0．8L／min的条件下，可以达到最优的除藻效果。pH值的变化也直接影响除藻率，在pH值=8的弱碱性条件下，对藻类的去除效果最为理想。水力空化也可以提高混凝对UV254和浊度的去除效果。

A microbubble hydrodynamic cavitation device with enhanced coagulation was used to removal algae from water. The results showed that hydrodynamic cavitation could effectively improve the algae removal rate and reduce the coagulant consumption. When the dose of coagulant was 1 mg/L, 5 min of pretreatment with hydrodynamic cavitation increased the algae removal rate by 13% and 20 min of pretreatment with hydrodynamic cavitation increased the algae removal rate by 30% compared with the blank sample. However, 1 h of hydrodynamic cavitation could reduce coagulant consumption by 50% to achieve the same algae removal rate of 65%. Hydrodynamic cavitation time and air flow rate had a great influence on enhanced coagulation effect, and significant enhancement of algae removal rate could be achieved with hydrodynamic cavitation of 10 to 20 min and air flow rate of 0.5 to 0.8 L/min. The change of pH value could affect the algae removal rate as well, and the optimal pH for algae removal was about 8. Experiments showed that this method could successfully enhance the reduction of UV254 and turbidity.