紫球藻溶气气浮法采收条件研究

Recovery Conditions of Porphyridium cruentumCells by Dissolved Air Flotation

探讨溶气气浮法采收紫球藻细胞的可行性,较为详细地研究了气浮操作参数对气浮采收效果的影响,确定合适的紫球藻细胞溶气气浮采收工艺条件。结果表明,通过调节pH值,能够获得藻细胞絮体,从而为无絮凝剂添加的紫球藻细胞气浮采收创造了条件。确定的最佳溶气气浮工艺为:pH值10.1,溶气压力0.6MPa,溶气时间17h,溶气水进水流量60L/h,溶气水/原料藻液体积比1.0。在此条件下,紫球藻的采收效果很好,细胞采收率可达到90%以上,浓缩倍数可达到4左右。培养液藻细胞浓度的增加对细胞采收率影响不大,但会降低浓缩倍数。

Porphyridiumis a kind of important valuable microalgal species.It produces many active substances such as phycobiliprotein,polyunsaturated fatty acids（AA/EPA）and algal polysaccharide,which can be used as healthcare and pharmaceutical agents.However,high cost of its harvesting by conventional centrifugation always limits its profits in industrial scale production.The paper focused upon the feasibility of Porphyridium cruentumcells harvesting by air dissolved flotation.It was investigated that all operation factors such as the pH value of the culture medium,air saturation pressure（P）and saturation time（T）for the preparation of air dissolved water,flow rate（V）of air dissolved water and water-feed volume ratio（？？would influence the efficiency of air dissolved flotation.The suitable conditions were determined as pH 10.1,P 0.6MPa,T 17h,V 60L/h,and？？.0,under which the recovery rate and concentration fold of Porphyridiumcells could approach about 90%and 4,respectively.Increasing the concentration of Porphyridiumcells in the culture medium has no obvious effect on the recovery rate,but lowers the concentration fold.These results indicated that the method of changing pH to recover Porphyridiumcells was feasible,and provided important parameters for future design on practical scale of harvesting Porphyridiumcells using air dissolved flotation.techniques.