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采用振荡培养实验研究了纳米Fe0、纳米Si0和纳米Fe3O4对黄褐土中PCB77的降解作用。结果表明,土壤中PCB77投加量为20 mg kg-1,仅投加纳米Fe0时,投加量为40 mg g-1,反应24 h后PCB77含量接近最低,纳米Fe0对灭菌和未灭菌土壤中的PCB77降解过程均符合一级反应动力学,反应速率常数Kobs分别为0.0057 h-1和0.0081 h-1;反应64h后,反应体系中PCB77残留率分别为68.2%,和53.2%,可见灭菌土壤较未灭菌土壤中PCB77降解效果降低。纳米双元体系能促进PCB77的降解,当纳米Si0:纳米Fe0=1∶10时,土壤中PCB77降解效果最好,反应64h后,土壤中PCB77残留率仅为53%,当纳米Fe3O4∶纳米Fe0=1∶4时,土壤中PCB77降解效果较佳,反应64h后,土壤中PCB77残留率仅为42.5%。土壤中PCB77降解产物中除联苯外未发现其他降解产物,可能是PCB77在纳米Fe0表面连续脱氯的原因造成的。
Oscillatory culture experiments were carried out to study the degradation of PCB77 in yellow cinnamon by nano-Fe0, nano-Si0 and nano-Fe3O4. The results showed that the dosage of PCB77 in the soil was 20 mg kg-1, and the dosage of 40 mg g-1 was only 40 mg g-1 when the dosage of nano-Fe0 was added. The content of PCB77 in the soil was almost the lowest after 24 h reaction. The degradation process of PCB77 in the soil was in accordance with the first-order reaction kinetics and the Kobs of the reaction rate were 0.0057 h-1 and 0.0081 h-1, respectively. After the reaction for 64h, the PCB77 residues in the reaction system were 68.2% and 53.2% It can be seen that the degrading effect of PCB77 in the sterilized soil is lower than that in the non-sterilized soil. The nano-binary system can promote the degradation of PCB77. When the nano-Si0: nano-Fe0 = 1:10, the degradation effect of PCB77 in the soil is the best. After the reaction for 64h, the residual rate of PCB77 in the soil is only 53%. When nano-Fe3O4: nano-Fe0 = 1: 4, the degradation effect of PCB77 in soil is better. After 64 hours of reaction, the residual rate of PCB77 in soil is only 42.5%. PCB77 degradation products in the soil in addition to biphenyl did not find other degradation products, PCB77 may be in the surface of nano-Fe0 continuous dechlorination caused.