废弃印刷线路板资源化中的微生物

Microorganisms in the Resource Recovery of Waste Printed Circuit Boards

电子产品更新速度加快导致大量电子废弃物产生。废弃印刷线路板是金属资源和污染物的集合体,故其资源化和无害化备受关注。废弃印刷线路板的金属赋存状态、材料特性和结构特点与金属矿物有明显差异。废弃印刷线路板资源化常用微生物有嗜酸菌、产氰微生物和真菌。其中嗜酸菌和真菌多用于基本金属的浸出,产氰微生物多用于贵金属的浸出。嗜酸菌主要通过直接-间接作用机理回收金属;产氰微生物通过产生的氰化物浸出金属;真菌通过产生的有机酸对金属可进行酸解、络合、还原和生物富集。微生物回收废弃印刷线路板中零价金属的作用机理尚未达成共识,该机理的解析将成为研究热点。

The high renewal speed of electronic products has led to the generation of the plenty of Waste electronic and electric equipments. Waste printed circuit boards are aggregate of metals resources and pollutants, therefore, their resource and harmless treatment receive an increase amount of attention. The occurrence state of metals, the material and structural characteristics of waste printed circuit boards have obvious differences compared with metal minerals. The common microorganisms of resource recovery of waste printed circuit boards mainly include acidophilic bacteria, cyanogenic microorganisms and fungi. Among them, the acidophilic bacteria and fungi are frequently applied to leach the basic metals from waste printed circuit boards, and the cyanogenic microorganisms are commonly used to leach the precious metals. The acidophilic bacteria recycle metals by the direct-indirect leaching mechanisms. The cyanogenic microorganisms leach metals with the generated cyanide. The dissolution of metals with organic acids from the fungi is mainly by acidolysis, complexolysis, reduction and bioaccumulation. The recycling mechanism of zero-valent metals through microorganisms has not reached a consensus in waste printed circuit boards. Therefore, the analysis of biological leaching mechanism will become a research hotspot.