几种常用絮凝剂对饵料微藻的絮凝效应

The Flocculating Effect of Several Kinds of Frequently Used Flocculants on Bait Microalgae

采用3种常用絮凝剂明矾、氯化铁及甲壳素和3种饵料微藻球等鞭金藻、扁藻及塔胞藻,研究絮凝剂浓缩效应及其对藻细胞的影响.测定了絮凝剂对藻细胞的絮凝速率、形态变化及对双壳贝类西施舌的饵料效果.结果表明:明矾、氯化铁对扁藻及塔胞藻的絮凝速率较快(≤60min),而球等鞭金藻在120min以上才可基本完成沉淀;甲壳素对扁藻、塔胞藻及球等鞭金藻絮凝均不理想;所用絮凝剂质量浓度越大藻细胞絮凝速度越快,但藻细胞越容易形成大藻团,不利于藻细胞的重新培养;综合考虑絮凝用时、絮凝剂质量浓度及对藻细的损伤的影响,对于扁藻、塔胞藻而言,明矾最佳作用质量浓度分别为160,120mg·L-1,氯化铁最佳作用质量浓度均为40mg·L-1;而球等鞭金藻明矾为200mg·L-1,氯化铁为80mg·L-1,絮凝后的藻细胞形态未发生明显形变或破裂;用絮凝后的塔胞藻、球等鞭金藻投喂西施舌幼虫及稚贝,效果与普通藻无明显差异,表明絮凝后的塔胞藻、球等鞭金藻不影响西施舌的幼体生长,可应用于贝类人工育苗.

This paper used three kinds of flocculants including alum,ferric chloride and chitin to study the flocculating effect and the influence on three kinds of algal cells including Isochrysis galbana,Platymonas subcordiformis and Pyramimonas sp..The result determined the flocculating rate,the morphologic change of algae cells and the bait effect on Coelomactra antiquate.The result showed that alum and ferric chloride have faster flocculating rate to P.subcordiformis and P.sp.within 60min after the experiment beginning.But to I.galbana,they can be achieve substantially precipitation more than 120min.The flocculating effect of Chitin on I.galbana,P.subcordiformis and P.sp.were insignificant.The higher the initial flocculant concentration is,the easier for algal cells to form a large group,that is not good for the cultivation of algal cells.Considering about the time and concentration of flocculants and the damage effect on algal cells,the ideal effect concentration of alum should respectively be 160mg·L- 1and 120 mg·L- 1to P.subcordiformis and P.sp.and the ferric chloride both should be 40mg·L- 1.While to I.galbana,the concentration of alum is 200mg·L- 1and ferric chloride is 80mg·L- 1.The form of algae cells did not insignificant change and fracture after flocculation.There was no remarkable difference between the growth results of larvae and juvenile of C.antiquate feeded by algae before and after flocculation,which showed that I.galbana and P.sp.did not affect the growth of juveniles of C.antiquata after flocculation and could be applied to the artificial seedling of shellfish.