摘要
排泥水富集了原水中包含镉在内的大部分污染物,直接回用容易引发镉超标风险.以排泥水回用处理时絮体的"破碎-再絮凝"过程中镉的迁移转化为切入点,通过调控"破碎-再絮凝"关键工艺参数,以实现排泥水中镉的强化去除结果表明:絮体破碎过程和再絮凝过程,镉的迁移均以液相向固相迁移为主,液相中镉含量得以降低;提高破碎过程的破碎强度有助于排泥水中镉的去除,破碎强度由300r/min提高到600r/min时,液相中镉的去除率可由23.0%提高到38.8%.再絮凝过程中镉的去除效果与混凝剂的类型和投加量有关,无机盐和聚合无机盐对镉的去除效果较接近,且都存在最佳投加量范围;适量的阴离子型PAM有助于镉的去除."破碎-再絮凝"过程体系pH值对镉的去除影响显著,碱性条件下去除效率明显优于酸性条件.
Sludge water amassed the most pollutants of raw water in water treatment plants,the direct reuse may result in the risk of pollutant concentrations exceeding the standard values,e. g.cadmium. This paper studied the transformation of cadmium in the processes of＂brokenrecoagulation＂during the reuse treatment of sludge water,and tried to enhance the removal efficiency of cadmium by optimizing of operating parameters of the ＂broken-recoagulation ＂processes.The results showed that the main transformation of cadmium was from liquid to solid.Cadmium concentration in liquid could be decreased during the ＂broken-recoagulation ＂processes of sludge water. The increasing of broken strength proved to stimulate the removal of cadmium,i.e. the removal efficiency could be enhanced from 23. 0% to 38. 8% as the broken strength increased from 300 r/min to 600 r/min. The removal efficiency of cadmium during recoagulation was affected by the types and dosages of coagulants. Both inorganic salt and polymeric inorganic salt performce almost the same removal effect,and had each optimal dosage range for the removal of cadmium.Meanwhile,the increasing of removal efficiency for cadmium was observed during recoagulation with Anionic PAM.The pH value of has significant influence on the removal of cadmium in the ＂broken-recoagulation＂process,the removal efficiency was higher in lkaline condition than acid.
出处
《应用基础与工程科学学报》
EI
CSCD
北大核心
2017年第6期1105-1113,共9页
Journal of Basic Science and Engineering
基金
国家自然科学基金(青年科学基金51409211)
湖南省重点研发计划项目(2015SK20033)
关键词
除镉
排泥水
破碎-再絮凝
PH值
removal of cadmium
sludge water
broken-recoagulation
pH
