颗粒物对混凝过程及超滤膜污染的影响  

Effect of particulate matter on coagulation process and ultrafiltration membrane contamination

作　　者：王子婕 徐慧[2] 庾俊杰 赵传靓 王东升[2] WANG Zi-jie;XU Hui;YU Jun-jie;ZHAO Chuan-liang;WANG Dong-sheng(School of Civil Engineering,Chang’an University,Xi’an 710061,China;State Key Laboratory of Environmental Aquatic Chemistry,Research Center for Eco-Environmental Sciences,Chinese Academy of Sciences,Beijing 100085,China)

机构地区：[1]长安大学建筑工程学院,陕西西安710061 [2]中国科学院生态环境研究中心,环境水质学国家重点实验室,北京100085

出　　处：《中国环境科学》2022年第10期4621-4630,共10页China Environmental Science

基　　金：中国科学院饮用水科学与技术重点实验室专项经费资助项目(20Z02KLDWST);国家自然科学基金资助重点项目(52030003)。

摘　　要：以nm-SiO_(2)和μm-SiO_(2)体系为研究对象,使用3种不同Al形态的混凝剂(AlCl_(3)、Al1_(3)和Al_(30))进行混凝-超滤实验,考察不同pH值下SiO_(2)去除率、出水余Al及混凝预处理对膜通量的影响,借助马尔文激光粒度仪、SEM、BET和AFM表征絮体性质及在超滤膜表面的分布和作用力.结果表明,nm-SiO_(2)体系中SiO_(2)去除率均低于μm-SiO_(2)体系,在纳米颗粒物体系中投加混凝剂后膜通量从0.68分别提升至0.96(AlCl_(3))、0.86(Al_(13))和0.87(Al_(30)),微米颗粒物体系中投加3种混凝剂后膜通量从0.79提升至0.80~0.84.微米级颗粒物是颗粒间的碰撞,纳米级颗粒物主要以团聚态的形式碰撞.低聚态铝(Al_(a))和颗粒物形成絮体的粒径均大于150μm,体系zeta电位为负与膜表面产生斥力;在中性条件下Al_(13)与颗粒物形成絮体的强度因子远高于AlCl_(3)和Al_(30),中聚态铝(Al_(b))将膜孔内部较小颗粒物堵塞形成的不可逆膜污染转移成膜孔表面的可逆膜污染;高聚态铝(Al_(c))具有较强吸附架桥和网捕卷扫能力,无定形、不规则的团聚态小颗粒在这一过程中形成较大絮体缓解膜污染.Taking nm-SiO_(2) andμm-SiO_(2) systems as the research objects,the coagulation-ultrafiltration experiments were carried out using three coagulants with different Al forms(AlCl_(3),Al_(13) and Al_(30))to investigate the removal rate of SiO_(2),the residual Al and coagulation pretreatment on membrane flux at different pH values.The properties of flocs and their distribution and interaction on the ultrafiltration membrane surface were characterized by Malvern laser particle sizer,SEM,BET and AFM.The results showed that the removal rate of SiO_(2) in the nm-SiO_(2) system was lower than that in theμm-SiO_(2) system.The membrane flux was increased from 0.68 to 0.96(AlCl_(3)),0.86(Al_(13))and 0.87(Al_(30)),respectively,after adding coagulants to the nanoparticle system.The membrane flux increased from 0.79 to 0.80~0.84 after adding three coagulants to the micron particle system.Micron-sized particles are collisions between particles,while nano-sized particles mainly collide in the form of agglomerates.The particle size of flocs formed by oligomeric aluminum(Al_(a))and particles are all larger than 150μm,and the zeta potential of the system is negative to generate repulsion with the membrane surface.Under neutral conditions,the strength factor of Al_(13) and particulate matter forming floc is much higher than that of AlCl_(3) and Al_(30).Intermediate aluminum(Al_(b))transfers the irreversible membrane fouling formed by the clogging of smaller particles inside the membrane pores to reversible membrane fouling on the surface of the membrane pores.Polymeric aluminum(Al_(c))has strong adsorption bridging and net sweeping ability,and the small amorphous and irregular agglomerated particles form larger flocs in this process to alleviate membrane fouling.

关 键 词：颗粒物形态 Al形态 絮体 混凝-超滤 膜污染 

分 类 号：X703.5[环境科学与工程—环境工程]