氮源对氧化亚铁硫杆菌浸提废旧印刷线路板覆层铜的影响研究

Effect of Nitrogen Sources on Copper Recovery from Waste Printed Circuit Boards by Thiobacillus ferrooxidans

采用摇瓶实验,在170rpm、30℃下,以氧化亚铁硫杆菌(Thiobacillus ferrooxidans)SW-02为浸提菌株,研究氮源对氧化亚铁硫杆菌浸提废旧印刷线路板覆层铜的影响。分析发现,以(NH4)2SO4作为氮源含量为1g/L时,浸提84h后铜浓度达到2.73g/L,铜的浸出效率较好。而采用(NH4)2HPO4作为氮源替代(NH4)2SO4,(NH4)2HPO4加入量在1g/L时效果较好,浸提84h后铜浓度达到3.52g/L。当(NH4)2HPO4在2g/L及以上时,会抑制细菌生长,导致浸出效率降低。实验结果表明,以(NH4)2HPO4作为氧化亚铁硫杆菌生长所需氮源,其浸出废旧印刷线路板覆层铜的效果优于(NH4)2SO4,最佳含量为1g/L。

Effect of nitrogen sources on copper recovery from waste printed circuit boards by Thiobacillus ferrooxidans was in- vestigated at 30℃ and a shaker rotary speed of 170 rpm. The results showed that when （NH4）2SO4 was used as nitrogen source, the concentrations of Cu leached into the aqueous phase after a 84-hour leaching process reached 2.73 g/L which could increase to 3.52 g/L when the nitrogen source changed to （NH4）2 HPO4. While the growth of bacteria was inhibited and led to low copper recovery when the concentrations of （NH4）2 HPO4 were above 2 g/L. It is concluded that （NH4）z HPO4 is a better nitrogen source than （NH4）2SO4 in leaching of copper from waste printed circuit boards by T. ferrooxidans, and the optimal concentrations of （NH4）2HPO4 are 1 g/L.