摘要
筛选得到的荧光假单胞菌(Pseudomonas fluorescens)产生的絮凝剂——PF-2在处理高岭土悬浊液时,具有用量少、絮凝效果好等优点,对高岭土悬浊液的絮凝率可达96.5%。呈色反应和紫外扫描的测定结果表明,PF-2大部分为胞外分泌的多糖,含有少量的核酸,提取后每升发酵液可制得絮凝剂粗品2.3g;ζ电位测定及氢键和离子键检验结果表明,PF-2与高岭土颗粒之间的作用力为离子键;红外光谱扫描分析PF-2中含有O—H、C—H、C=C和C—O—C等多糖的特征吸收峰;利用扫描电镜观察絮体形态表明,絮体结构密实,其絮凝机制为PF-2和高岭土以离子键的形式结合,之后通过架桥作用絮凝沉淀。
The microbial flocculant PF-2 produced by Pseudomonas fluorescens is attractive because of its low dosage and outstanding flocculating capability; 96.5% turbidity reduction of a kaolin suspension （0.4 g in 100 mL of test solution） was achieved in this study. The color reaction test results coupled with the UV spectrum confirmed that PF-2 was mostly extracellular polysaccharides with some nucleic acids; its yield was about 2.3 g/L of the growth media. Based on the Zeta potential measurements, the force connecting PF-2 and kaolin clay particles was due to both the ionic bond and the hydrogen bond. The infrared spectrum of PF-2 showed the presence of O--H, C--H, C=C, C--O--C and characteristic absorption peaks of polysaccharide. PF-2 produced large and dense floes beneficial to flocculation and sedimentation of suspended solids. The outstanding PF-2/CaCl2 flocculation of the kaolin suspension resulted from the effective initial neutralization of the surface negative charge and double layer compression by Ca^2＋ followed by the enhanced attraction of PF-2 for the kaolin particles due to the combined actions of bonding force, bridging and adsorption.
出处
《环境污染与防治》
CAS
CSCD
北大核心
2008年第2期37-40,44,共5页
Environmental Pollution & Control
基金
江苏大学高级人才基金资助项目(No.04JDG017)
关键词
微生物絮凝剂
成分分析
絮凝机制
多糖
吸附架桥
microbial flocculant
component analysis
flocculating mechanism
polysaccharide
bridging and adsorption
