电场强化嗜酸性氧化亚铁硫杆菌(Acidithiobacillus ferrooxidans) MA-Y1固定化细胞浸出废弃电路板的铜和镍

An electric current improves Cu and Ni leaching from waste printed circuit boards by immobilized Acidithiobacillus ferrooxidans MA-Y1

摘要:

目的 废弃电路板中有色金属含量约为40%，是天然矿石的40倍以上，堪称名副其实的“城市矿山”。为了实现废弃电路板的高效绿色回收，开发高效浸出电路板中有色金属的浸出体系。方法 利用嗜酸性氧化亚铁硫杆菌(Acidithiobacillus ferrooxidans) MA-Y1构建电路板的生物浸出体系，并通过引入电场进一步强化铜和镍的浸出效率。结果 最佳浸出工艺参数为：电路板浓度80.0 g/L，电路板粒径4.0 cm，液体流速2.0 L/min，电流70.0 mA。在此条件下，铜和镍的浸出率分别为84.0%和75.3%，与无电场生物浸出体系相比，分别提高了15.8%和17.1%。结论 外加电场显著提升了A. ferrooxidans MA-Y1回收电路板中铜和镍的能力。

关键词:固定化;响应面;电路板;嗜酸性氧化亚铁硫杆菌;生物浸出

Abstract:

Objective Waste printed circuit boards (PCBs) contain about 40% non-ferrous metals, which is more than 40 times that of natural ores, and thus they are known as a veritable “urban mine”. To achieve efficient and green recycling of PCBs, this study developed a leaching system that can efficiently leach non-ferrous metals from PCBs.Methods Acidithiobacillus ferrooxidans MA-Y1 was used to construct a bioleaching system for PCBs. Additionally, an electric current was introduced to strengthen the Cu and Ni leaching from PCBs.Results The optimal leaching parameters were addition of PCBs at 80.0 g/L, particle size of 4.0 cm, liquid velocity of 2.0 L/min, and electric current of 70.0 mA. Under these conditions, the leaching ratios of Cu and Ni from PCBs were 84.0% and 75.3%, respectively, which represented increases of 15.8% and 17.1% compared with the case without electric current.Conclusion An electric current improves the ability of A. ferrooxidans MA-Y1 to recover Cu and Ni from PCBs.

Key words:immobilization;response surface;printed circuit boards;Acidithiobacillus ferrooxidans;bioleaching