产氰混合菌浸出废弃线路板中金的实验研究

Study on Leaching of Gold from Waste Circuit Boards by Using Cyanogenic Bacteria

利用荧光假单胞菌和绿脓杆菌混合生物浸取废弃线路板中的金元素,通过产氰细菌在生长代谢中产生的次生代谢物CN-与废弃线路板粉末中的金发生络合反应,生成可溶性的金络合物,从而将线路板中的金浸取出来。由于浸金过程存在多种影响因素,本实验选用了混合接种比例、菌液加入量、粉末投加量以及NaCl浓度等因素进行了浸金实验,通过控制各单一变量,并进行平行实验,探究生物浸金的最佳条件。在V(荧光假单胞菌)∶V(绿脓杆菌)=2∶1,菌液量为5 mL,粉末投加量0.1 g,NaCl浓度为3.4×10^-1 mol·L^-1时,细菌的浸金率是最高的,最高的浸金率为65.33%。

In this paper,the mixed organisms of Pseudomonas fluorescens and Pseudomonas aeruginosa were used to extract gold elements from waste printed circuit boards,and the secondary metabolites CN-produced by cyanogen-producing bacteria in growth and metabolism occurred with gold in waste printed circuit board powder.The complexation reaction generates a soluble gold complex that leaching out metals from waste printed circuit boards.Factors such as the bacterial solution addition ratio,the bacterial solution addition amount,the powder addition amount,and the NaCl concentration were selected for the gold leaching experiment.By controlling each single variable,parallel experiments were performed.Under the condition of V(Pseudomonas fluorescens)∶V(Pseudomonas aeruginosa)=2∶1,5 mL bacterial solution,0.1 g WPCB powder,3.4×10^-1mol·L^-1 NaCl,the highest leaching efficiency of gold was 65.33%.