高藻太湖表层水深井加压混凝浓缩技术研究及应用

Application of Deep Well Pressurized Coagulation Concentration Technology in the Treatment of High Algae-laden Surface Water from Taihu Lake

为了探索高藻太湖表层水深井加压混凝沉淀浓缩技术的可行性,并优化技术参数后将其应用于工程实践,采用混凝实验优化了混凝剂投加量,采用静态沉淀实验测定了加压混凝高藻太湖表层水颗粒的沉淀速度,采用中试研究了深井加压混凝沉淀高藻太湖表层水的处理效果。结果表明,将PAC/干藻(质量比)控制在16%~32%、PAM/干藻(质量比)控制在0.3%~0.4%,混凝后高藻太湖表层水颗粒的沉淀速度可达47 cm/min左右,沉淀池表面负荷可达10 m3/(m^(2)·h),实际工程中可将平均含固率为0.5%的高藻太湖表层水浓缩至平均含固率为4.08%,使出水浊度为1.83~8.33 NTU,叶绿素a浓度为6.32~11.72μg/L,TN为0.30~5.20 mg/L,TP为0.03~0.26 mg/L。

This paper optimized the dosage of coagulant by coagulation experiment,determined the settling velocity of the particles in high algae-laden surface water from Taihu Lake after pressurized coagulation through static settling experiment,and investigated the performance of deep well pressurized coagulation for the treatment of high algae-laden surface water in a pilot test,so as to explore its feasibility for the concentration of high algae-laden surface water,optimize the technical parameters and apply it to engineering practice.When the ratio of PAC dosage to dry weight of algae was controlled at 16%-32%,and the ratio of PAM dosage to dry weight of algae was controlled at 0.3%-0.4%,the settling velocity of particles in the high algae-laden surface water from Taihu Lake after pressurized coagulation reached approximately 47 cm/min,and the surface load of the settling tank reached 10 m/(m^(2)·h).In the actual project,the high algae-laden surface water could be concentrated from the average solid content of 0.5% to 4.08%,resulting in the effluent turbidity,chlorophyll-a,TN and TP decreased to 1.83-8.33 NTU,6.32-11.72μg/L,0.30-5.20mg/L,and 0.03-0.26mg/L.