Abstract:

The complex of PVA solution and sodium alginate solution crosslinked by Ca(NO3)2 as entrapment medium was prepared. The mixture of Acidithiobacillus ferrooxidans suspension and the entrapment complex were extruded into a solution of Ca(NO3)2 to form beads, and then the beads were frozen at -20°C for 1~2d and thawed at room temperature. A maximum oxidation rate of 2.90g Fe2+ / (L•h) was achieved in a packed-bed bioreactor with immobilized cells at the dilution rate of 0.5/h. In addition, the operation of this method was very simple, and the gelation solution (calcium nitrate) used was of low toxicity and very cheap. Moreover, the oxidation activity of the beads obtained by this technique was excellent even under non-sterile conditions. So its application on a commercial scale would be practicable.

摘要： 用Ca(NO3)2凝固聚乙烯醇(PVA)、海藻酸钠和氧化亚铁硫杆菌复合水溶胶，并把成形后的颗粒置低温冷冻，从而形成固定化颗粒。用该颗粒填充固定床生物反应器进行连续操作，考察了不同稀释率下固定床生化反应器氧化Fe2+ 的情况，在温度31 ℃、pH值1.8、稀释率0.5 h—1条件下，Fe2+最大氧化速率达2.90 g/(L•h)。系统即使在没有灭菌的情况下，稳定性保持良好，具有较好的应用前景。