胞外分泌物和天然有机物对混凝的影响  

Effect of Extracelluar Organic Matter and Natural Organic Matter on Coagulation

作　　者：施国键[1] 乔俊莲[2] 王国强[1] 吴烨[3] 张普[1] 董磊[2] 

机构地区：[1]同济大学化学系,上海200092 [2]同济大学污染控制与资源化研究国家重点实验室,上海200092 [3]东华大学环境科学与工程学院,上海200092

出　　处：《环境科学》2010年第3期673-677,共5页Environmental Science

基　　金：国家水体污染控制与治理科技重大专项(2008ZX07421-002)

摘　　要：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.Influence of EOM and NOM on removal of algae and turbidity was investigated.The result showed that EOM had both beneficial and harmful effects on coagulation,it hindered the charge neutrality of the flocculant.Zeta potential of algae decreased from-40.6 mV to-14.7 mV,only when the modified chitosan was added above 0.2 mg·L^-1.But it became a coagulant aid when it combined with flocculant.The experiment indicated that turbidity removal would reach the peak efficiency（96%） with appropriate concentration of EOM（5.18 mg·L^-1）,therefore EOM would enhance the removal efficiency.NOM had the more negative effect on coagulation,the optimum removal efficiency of algae and turbidity decreased by 11% and 18% separately.Besides,the optimum dosage of modified chitosan increased from 0.35 mg·L^-1 and 0.1 mg·L^-1 to 0.7 mg·L^-1 and 0.3mg·L^-1 respectively.So it is the key point to take advantage of EOM and remove the NOM in practice,as a result the flocculant loading will be decreased,the removal efficiency will be improved.

关 键 词：胞外分泌物 天然有机物 混凝 藻 高岭土 

分 类 号：X52[环境科学与工程—环境工程]