藻类不同生长周期对其混凝去除的影响

Conference on Environmental Pollution and Public Health (CEPPH2011)

Variability of Coagulation Effect to

Algae with Different Age

Junlian QIAO1, Qing LEI2

1

College of Environmental Science and Engineering, Tongji University, Shanghai, 200092

2

College of Chemical, Tongji University, Shanghai, 200092

Email: qiaoqiao@tongji.edu.cn

Abstract: This paper studied the growth cycle characteristics of laboratory pure-culture Microcystis aeruginosa and its impact on coagulation efficiency of PAC coagulant. The results showed the order of algae removal effectiveness was: stationary phase>logarithmic phase>early senescence phase>late senescence phase. The reason may be related to the Zeta potential changes and the content and components of Extracelluar Organic Matter (EOM) in different growth phase. In early senescence phase and late senescence phase, the concentration of EOM significantly increased, and it competed with algal cells for coagulant, which resulted in the decrease of coagulation effectiveness. While the concentration of EOM was almost equal in stationary phase and logarithmic phase, but the components with the molecular weight more than 200Kda, which played a coagulant effect, increased by 13.52% in stationary phase, compared with that in logarithmic phase. That was one of the leading reasons why the algae removal efficiency in stationary phase excelled that in logarithmic phase.

Keywords: Microcystis aeruginosa; growth phase; coagulation

藻类不同生长周期对其混凝去除的影响

乔俊莲，雷青2

1

1

同济大学环境科学与工程学院，上海，200092

2

同济大学化学系，上海，200092 Email: qiaoqiao@tongji.edu.cn

摘 要：以实验室纯培养的水华优势藻铜绿微囊藻为研究对象，采用聚合氯化铝（PAC）混凝剂，研究了铜绿微囊藻不同生长周期混凝去除规律及机理，结果表明：各个藻生长阶段除藻效果为：稳定期＞对数期＞衰亡前期＞衰亡后期。其原因可能与不同生长期Zeta电位变化、胞外分泌物（ＥＯＭ）含量及组分不同有较大关系，藻处于衰亡前期和衰亡后期ＥＯＭ含量显著增大，与藻细胞争夺混凝剂，干扰混凝效果；稳定期和对数期藻液中EOM的值几乎相等，但稳定期比对数期分子量200Kda以上的

大分子含量增加13.52%，起到了助凝剂的效应，是造成稳定期混凝效果优于对数期的主要因素之一。关键词：铜绿微囊藻；生长周期；混凝

由于藻细胞是一种具有生命活性的微生物，同其他悬浮在水中的固体颗粒不同，絮凝沉降过程也同固体颗粒有着一定的区别，藻细胞的生理与形态特征对混凝过程具有较大的影响[1-3]。藻细胞的生长与其他微生物同样会出现停滞期、对数期、稳定期、衰亡期(内源呼吸期)几个阶段，随着生长期和代谢条件的变化，与藻细胞壁相联系的官能团(主要是羧基,偶尔也有酚基、羟基)的浓度和反应会发生波动，直接影响藻细胞的负电荷密度和等电点。由于这些官能团多存在于藻细胞的EOM中，因此，EOM的性质及其动态变化必然

基金项目：国家科技支撑计划项目(2006BAJ04A09)

罗晓鸿[5]等用小球藻及月牙藻不同影响藻类的混凝[4]。

浓度及生长周期对混凝的影响后发现：小球藻和月牙藻在对数期干扰混凝，稳定期和衰亡期时，低浓度促进混凝，高浓度干扰混凝。Konno[6]发现藻细胞的最佳混凝剂(Al盐)量随培养时间递增,到对数期末达最大值，在稳定期反向降低，随后几乎保持为常数。本文利用聚合氯化铝为混凝剂，考察了铜绿微囊藻不同生长周期的混凝效果，分析了影响其混凝效果的因素。

1 实验材料与方法

1.1 实验仪器

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