中文摘要：

以絮凝率为指标,比较Ca（OH）_2、FeCl_3、Fe_2（SO_4）_3、聚丙烯酰胺、聚合氯化铝、硅藻土、壳聚糖-海藻酸钠和甲壳素等8种絮凝剂对3-羟基丙酸（3-HP）发酵液的絮凝效果,筛选出壳聚糖-海藻酸钠复合絮凝剂。观测絮凝前后菌体结构,探讨壳聚糖絮凝机制,考察壳聚糖用量、发酵液p H和搅拌时间对絮凝的影响;随后探究活性炭粒度、发酵液p H和时间等因素对脱色率的影响;通过正交试验确定3-HP发酵液预处理的最优工艺。结果表明：当复合絮凝剂中壳聚糖和海藻酸钠用量均为1.60 g/L,3-HP发酵液pH 7,搅拌时间20 min,静置30 min时,絮凝效果最佳,菌体絮凝率达99.10%,且3-HP损失率小于2.00%;当活性炭粒度小于150μm,用量5.00 g/L,接触时间30 min时,脱色效果最佳,脱色率达46.45%。

英文摘要：

In this study,we investigated the flocculation ratios of 3-hydroxypropionic acid（3-HP） fermentation broth treated with eight different flocculating agents,namely Ca（OH）_2,FeCl_3,Fe_2（SO_4）_3,polyacrylamide,aluminium chlorhydrate,kieselguhr,chitosan-sodium alginate and chitosante. The results showed that the chitosan-sodium alginate complex was most effective. The flocculation process was observed by scanning electron microscopy（SEM）. The effects of varying the chitosan dosage,p H value and stirring time on flocculation were investigated.Also,the influence of activated carbon particle size,p H value and time on the decoloration pocess were individually examined. Finally,orthogonal design was employed to optimize the pretreatment of the 3-HP fermentation broth.The optimum flocculation conditions were found to be as follows： 1. 60 g/L of chitosan,1. 60 g/L of sodiumalginate,p H 7,20 min of turbidity time,and 30 min of settlement. Under these conditions,the flocculation ratio reached99. 10% and the loss ratio of 3-HP was less than 2%. With an activated carbon size of 150 μm,a concentration of5. 00 g/L,and incubation time of 30 min,the decoloration ratio reached 46. 45%.