摘要
对比研究了常规混凝和分级混凝过程的混凝特性。结果表明,分级混凝的沉后水浊度更低,混凝剂的高效除浊范围更宽,沉后水浊度下降速率更高,ζ电位更低。常规混凝过程中,混凝剂投加量越多絮体形成速率越高,但达到最高值后的下降速率也越大;分级混凝过程中的絮体形成速率始终在相同的混凝时间达到最大,随后均以相同的趋势下降,絮体形成过程主要取决于第1级投药量,第2级投药量的变化不会显著影响絮体形成速率。与常规混凝相比,分级混凝的絮体密度较高、呈明显的团簇状、结构更密实、边缘较清晰,絮体的粒径较小、强度因子更高、抗剪切能力更强。研究结果可为分级混凝过程作用机制的建立提供技术支持。
The coagulation characteristics of conventional coagulation and the grading coagulation were comparatively studied.The results showed that,grading coagulation not only reduced the effluent turbidity,made the effective range of coagulant wider,but also increased the decreasing rate of the effluent turbidity and reduced theζpotential.In conventional coagulation process,the more coagulant dosage,the higher floc formation rate,but the greater decreasing rate after reaching the maximum value.On the other hand,in grading coagulation process,the floc formation rate reached the maximum at the same coagulation time all the time,and then decreased with the same trend,this phenomenon could be explained that the floc formation process mainly depended on the first-stage dosage and was not significantly affected by the change of the second-stage dosage.Compared to conventional coagulation,the flocs with not only higher density,obvious cluster shape,clearer edges,denser structure,but also smaller particle size,higher strength factor and stronger shear resistant were formed in grading coagulation.This study provides a technical support for the establishment of action mechanism in the grading coagulation process.
作者
方晓博
杨艳玲
李星
杜鹏
FANG Xiaobo;YANG Yanling;LI Xing;DU Peng(College of Architecture and Civil Engineering,Beijing University of Technology,Beijing 100124,China)
出处
《水处理技术》
CAS
CSCD
北大核心
2020年第3期86-90,共5页
Technology of Water Treatment
基金
国家自然科学基金项目(51478010).
关键词
分级混凝
混凝剂
投加方式
除浊效能
絮体特性
grading coagulation
coagulant
dosing method
turbidity removal efficiency
floc properties
