以铀矿渣为载体联合PEG2000的细菌固定化培养

以铀矿渣为载体，采用逐次降低接种率循环培养的方法，开展了氧化亚铁硫杆菌的固定化培养试验，研究了聚乙二醇2000（PEG2000）对游离细菌和铀矿渣载体柱中固定化细菌生长的影响。试验结果表明：90 mg/L PEG2000对游离细菌的生长促进作用最大。铀矿渣和K3环材料均可作为载体进行细菌固定化培养。固定化完成时，其亚铁离子的平均氧化速率分别稳定在0.6和0.5 g/(L?h)附近。90 mg/L PEG2000对循环培养和连续培养阶段的固定化细菌生长均具有促进作用。循环培养阶段，可使Fe2+氧化为Fe3+的时间缩短约1/3。连续培养阶段，PEG2000能够促进固定化细菌对亚铁离子的氧化速率，在0.5 L/h进液流量时，未加PEG2000的亚铁离子氧化速率为7.04 g/(L?h)，而加PEG2000的，达到了8.18 g/(L?h)，亚铁离子氧化效率提高了16.2%。

Immobilization Culture of Bacteria Using Uranium Slag as Carrier Combined with PEG2000

Using uranium slag as carrier, immobilization culture test of Thiobacillus ferrooxidans was carried out by adopting the method of successively reducing the inoculation rate and cyclic culture to investigate effect of PEG2000 on bacterial growth. The test results show that 90 mg/L PEG2000 has the highest effect on growth of free bacteria. Both uranium slag and K3 ring material can be used as carriers for immobilized bacteria culture. When the immobilization is completed, the average oxidation rate of its ferrous ions is stable at around 0.6 and 0.5g/(L?h) respectively. 90 mg/L PEG2000 has great promoting effects on cyclic culture and continuous culture stages. In the cyclic culture stage, time for oxidation of Fe2+ to Fe3+ can be shortened by about 1/3. In the continuous culture stage, PEG2000 can promote the oxidation rate of ferrous ions by immobilized bacteria. When influent flow rate is 0.5 L/h, the oxidation rate of ferrous ions without PEG2000 is 7.04 g/(L?h), while it is 8.18 g/(L?h) with addition of PEG2000, where the oxidation efficiency of ferrous ions rises by 16.2%.