藻形态及混凝剂组成对混凝-超滤过程的影响

发布时间：2018-01-10 06:10

本文关键词：藻形态及混凝剂组成对混凝-超滤过程的影响　出处：《环境科学》2017年08期 　论文类型：期刊论文

【摘要】：为了保证藻类暴发阶段优质的饮用水供应,提高藻类的去除率,缓解藻类对水处理过程的影响,本研究以铜绿微囊藻(蓝藻)、小球藻(绿藻)和小环藻(硅藻)这3种不同形态藻细胞为研究对象,使用了3种具有不同铝形态分布的混凝剂[Al_2(SO_4)_3(AS)、Al_(13)、Al_(30)]进行混凝-超滤实验.在分离胞外有机物(EOM)的情况下,考察混凝过程中絮体的特性(粒径,强度因子,恢复因子)以及不同条件下形成的絮体对膜通量的影响.结果表明Al_(13)与Al_(30)的混凝作用以静电簇作用为主导,AS主要是以电中和作用为主导.对于铜绿微囊藻与小球藻体系,由于藻颗粒表面存在一定的凹陷,当Al_(13)与Al_(30)做混凝剂时,在投加量较低的情况下,吸附在颗粒表面凹陷处的混凝剂“失活”,其他部位由于仍带有一定的负电荷而造成絮体形成不明显,而AS做混凝剂时,混凝机制主要是电中和作用,可以明显降低颗粒之间的排斥力,在较低投加量下即可形成絮体.对于小环藻体系,由于其藻细胞呈现光滑的表面,Al_(13)与Al_(30)可有效发挥其静电簇作用机制,絮体在较低投加量下即可有效形成.膜通量与絮体粒径有明显的相关性,絮体粒径越大,超滤过程中形成的沉积层越疏松,膜比通量越大.
[Abstract]:In order to ensure the supply of high quality drinking water, improve the removal rate of algae and alleviate the influence of algae on the process of water treatment, microcystis aeruginosa (cyanobacteria) were used in this study. Chlorella microphylla (Chlorophyta) and Cyclophyta (diatom), three different species of algal cells, were studied. Three kinds of coagulants with different aluminum species were used. [In the case of separation of extracellular organic matter (EOM), a coagulation-ultrafiltration experiment was conducted. The characteristics of flocs (particle size, strength factor) during coagulation were investigated. The results showed that the coagulation effect of AlStue 13) and Alsp 30) was dominated by electrostatic cluster action. For the microcystis aeruginosa and Chlorella aeruginosa system, due to the existence of a certain depression on the surface of algae particles, when Alf13) and Alpene 30) are coagulant coagulants. In the case of low dosage, the coagulant "deactivated" adsorbed on the hollow part of the particle surface, other parts are still with certain negative charge, resulting in flocs formation is not obvious, and when as is used as coagulant. The coagulation mechanism is mainly electric neutralization, which can obviously reduce the repulsive force between particles, and form floc at lower dosage. For the microcystis, the algal cells show smooth surface. Alsin-13) and Alac _ (30) can effectively exert the mechanism of electrostatic cluster action, and the flocs can be formed effectively at a lower dosage. The membrane flux has a significant correlation with the particle size of the flocs, and the larger the particle size of the flocs is. The looser the sediment layer formed during ultrafiltration, the larger the specific flux of the membrane.
【作者单位】：西安建筑科技大学环境与市政工程学院;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;
【分类号】：TU991.2
【正文快照】： 北京100085)近年来,日益严重的水体富营养化问题已成为全球性的环境问题.水体的富营养化会导致水体中藻类的大量生长繁殖,不仅会破坏水体的生态平衡,而且会严重地干扰水处理过程[1].例如,原水中的大量藻类会堵塞滤床、恶化水质、堵塞或腐蚀管道、增大混凝剂投加量[2]、产生嗅

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