【摘要】 采用自制的脉冲鼓泡压力溶气气浮系统进行小球藻Chlorella sp.的连续采收试验,首先设计正交试验,用烧杯法确定合适的絮凝药剂条件,包括pH值、阳离子凝聚剂FeCl3用量和絮凝剂聚丙烯酰胺的用量;在最优药剂条件下,研究处理量、入料高度和循环溶气水量对分离柱流体流动和气浮采收效果的影响。试验结果表明:pH值在7~10时,对小球藻Chlorella sp.的促凝效果不明显,增加FeCl3的用量有助于絮凝;当pH达到11时,可显著促进小球藻的絮凝,絮凝率达96%以上,其他药剂的剂量对絮凝效果不再有明显作用;气浮处理量、入料高度和循环溶气水量一起决定了分离柱的流体环境,进而影响气泡与小球藻细胞絮凝体的碰撞粘附效率,对气浮采收效率产生影响。分析试验结果表明,适当增大分离柱的高度、控制合理的循环溶气水量能够有效提高微藻的气浮分离效率。更多还原

【Abstract】 A dissolved air flotation experiment that dissolving air with pulse bubble-liquid in a pressure tank was used to harvest biomass of Chlorella sp. In order to make the optimum addition solution of flocculation agents, orthogonal beaker experiments was carried out to investigate the effect of coagulant(FeCl3), flocculant(PAM) and pH on flocculation of Chlorella sp.. Then,the flow rates of feed and circulation water used for dissolving air and feed site were changed during the flotation experiments to understanding their effect on biomass recovery rate, while agents were added according to optimum solution offered by beaker experiment. The results showed that, when pH was adjusted from 7 to 10, flocculation rate rised with the increase amount of FeCl3 but no obvious change due to pH itself;This situation reversed when pH value up to 11, in this pH value,algae cells flocculated strongly that the flocculation rates were over 96%, and the influences of other agents could be neglected. During air flotation, feeding flow rate, circulation flow rate and feeding site constructed a certain flow pattern in the column, which determined the adhesion efficiency of flocs to bubbles and effect the flotation recovery ultimately. The results showed that a certain circulation flow rate and higher column can increase the air flotation harvesting rate.更多还原