摘要
疏浚泥浆吹填余水中含有大量胶体及微小颗粒物,直接排放将对受纳水体造成较大危害。依托京杭运河湖西航道疏浚工程展开现场试验,对比分析聚合氯化铝(PAC)和FeCl_3对余水中悬浮固体(SS)的去除效果。研究发现,疏浚泥浆落淤后的余水SS浓度较高,随着吹填时间的延长,余水SS浓度有明显增加的趋势。室内混凝小试试验表明,PAC、FeCl_3均能有效降低余水中的SS,PAC、FeCl_3的最佳投加量分别为39、17mg/L;在最佳投加量下,两种混凝剂对余水SS的混凝效果均随沉降时间延长而改善,前5min内FeCl_3的混凝效果比PAC好,5min后PAC的混凝效果更佳。现场中试试验显示,两种混凝剂均在较短时间取得较好的SS混凝效果。当以混凝剂最佳投加量及污染物排放达标为评价目标时,FeCl_3的处理费用分别为15.0、8.0元/h,PAC的处理费用分别为20.5、10.5元/h,FeCl_3的经济性均优于PAC。
The tail water from dredging engineering contained large amount of gel and fine particulate matters？ directly discharge of tail water would caused environmental hazard to receiving water body. Relying on dredging project in the Huxi Waterway of Grand Canal,field test were studied to analyze the effect of polymeric aluminium （PAC） and FeCls on SS removal from tail water of cofferdam. The study found that the SS content in tail water was very high,and it increased with the increasing of dredging time. The indoor coagulation experiments showed that PAC and FeCl3 could removal SS in tail water effectively,the best dosage of PAC and FeCl3 were 39,17 mg/L. Under the optimal dosage of two flocculating agent, the effect of flocculation enhanced when the flocculation time increased, and within the first 5 min of flocculation,the effect of FeCl3 was better than that of PAC, while PAC performed much better than FeCl3 after 5 min of flocculation. The pilot test showed that both two kinds of flocculants had good perform-ance of SS sedimentation in a relatively short period. The most economical flocculant was FeCl2 ,on the best processing efficiency and pollutant emission standards as the goal,the treatment cost of FeCl3 was 15.0,8.0 yuan/h,for PAC was 20.5,10.5 yuan/h,respectively.
出处
《环境污染与防治》
CAS
CSCD
北大核心
2017年第5期510-514,519,共6页
Environmental Pollution & Control
基金
江苏省交通科学研究计划项目(No.2013Y16)
关键词
疏浚泥浆
余水
悬浮固体
混凝剂
净化
dredging slurry
tail water
SS
flocculating agent
purification
