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分别研究了胞外分泌物(EOM)和天然有机物(NOM)对絮凝除藻及混凝除浊的影响.实验发现,EOM对混凝有利弊双重作用,它会阻碍絮凝剂的电中和作用,只有当改性壳聚糖投加>0.2 mg.L-1时藻表面电位才开始由-40.6 mV下降到-14.7 mV.但它一旦结合絮凝剂后便成为助凝剂.除浊实验发现,适宜浓度的EOM(5.18 mg.L-1)能使浊度去除率达到峰值(96%),所以EOM能提高混凝效果.而NOM则对混凝只起负面影响,加入NOM后最佳除藻及除浊率分别下降11%和18%,且絮凝剂最佳投加量分别由0.35 mg.L-1和0.1 mg.L-1上升到0.7 mg.L-1和0.3 mg.L-1,所以实际混凝除藻时,合理地利用EOM同时去除NOM是减少混凝药剂、提高混凝效果的关键.
The effects of extracellular secretions (EOM) and natural organic compounds (NOM) on flocculation algae removal and coagulation and turbidity removal were studied respectively.Experiments showed that EOM had the dual effect of coagulation, which hindered the electric neutralization of flocculants, Only when the modified chitosan dosage> 0.2 mg.L-1 algae surface potential began to decline from -40.6 mV to -14.7 mV, but it once combined with flocculant will become a coagulant.Exhaustion test found that, EOM can improve the coagulation effect when the appropriate concentration of EOM (5.18 mg.L-1) can make the turbidity removal rate reach the peak value (96%), while NOM has a negative impact on coagulation. Algae and turbidity removal rate decreased by 11% and 18% respectively, and the best flocculant dosage increased from 0.35 mg.L-1 and 0.1 mg.L-1 to 0.7 mg.L-1 and 0.3 mg.L- 1, so the actual coagulation algae removal, rational use of EOM while removing NOM is to reduce the coagulant, improve the coagulation effect of the key.