荧光假单胞菌从废弃线路板中浸金的实验研究

发布时间：2018-03-24 03:04

本文选题：废弃线路板　切入点：微生物冶金　出处：《青岛科技大学》2017年硕士论文

【摘要】：随着科技的不断发展和消费者对于高科技电子产品的消费能力的改变,电子废弃物的数量逐年呈指数增长。如果能够使用环保高效的回收技术对电子废弃物进行处理和资源化回收,可以达到保护环境和解决资源匮乏困境的双重目的。本文利用具有快速繁殖和较强适应能力的荧光假单胞菌(Pseudomonas fluorescens)从典型电子废弃物(废弃线路板)中浸出金,进一步探索实现环境友好的生物法冶金从实验室研究到规模化应用的可能性。首先通过硝酸酸浸预处理线路板,然后培养荧光假单胞菌,了解其生长代谢规律,为后续浸金实验做好准备。荧光假单胞菌的浸金过程受到很多因素的限制,如细菌的自身性质、氧气含量、温度、底物、pH、线路板种类与成分、矿浆浓度及线路板的预处理效果等。本文选择了pH、底物种类、物料加入量等因素进行了浸金实验,最后获得最佳浸金率。通过实验可知,经过酸浸预处理后,线路板粉末中金的含量从0.035 mg/g提升到了0.12 mg/g;金的浸金率随着浸出液pH的升高而增大,随细菌加入量的增多先增大后减小;随着物料加入量的增大而减少,而且受其影响程度较大,在物料添加量为0.5 g时,浸金率最高达到41.75%;底物的种类也影响浸金率,甘氨酸和蛋氨酸一起作为产氰前体时,浸金率在浸金后期阶段会有较大提高,最高达到54.20%,这是由于两种底物之间具有协同作用。金属离子和营养盐的加入可以大幅提高金的浸出率,在加入适量的NaCl后,金的浸出率最高可以达到66.62%。最后由经济效益分析发现,利用荧光假单胞菌从1吨废弃线路板中浸金可获纯利润1000元,最重要的是微生物回收金属可以同时实现经济效益和环境效益。
[Abstract]:With the development of science and technology and the change of consumer's ability to consume high-tech electronic products, The amount of e-waste is increasing exponentially year by year. If we can use environmental protection and efficient recycling technology to treat and recycle e-waste, In this paper, Pseudomonas fluorescens, which has rapid propagation and strong adaptability, is used to extract gold from typical electronic waste (waste circuit board). Further exploring the possibility of realizing environment-friendly bio-metallurgy from laboratory research to large-scale application. First, pretreatment of circuit boards by acid leaching of nitric acid, then culture of Pseudomonas fluorescein, to understand its growth and metabolism, The gold leaching process of Pseudomonas fluorescens is limited by many factors, such as the nature of bacteria, oxygen content, temperature, substrate pH, type and composition of circuit board. In this paper, pH, substrate type, material quantity and other factors were selected for gold leaching experiment, and the best gold leaching rate was obtained. Through the experiment, we can know that after acid leaching pretreatment, the gold leaching rate can be obtained. The gold content in the powder of PCB increased from 0.035 mg/g to 0.12 mg / g. The gold leaching rate increased with the increase of pH value of leaching solution, and then decreased with the increase of bacterial content, and decreased with the increase of material content. The gold leaching rate reached the highest of 41.75 when the material was added 0.5 g, and the type of substrate also affected the gold leaching rate. When glycine and methionine were used as precursor of cyanide production, the gold leaching rate increased greatly in the later stage of gold leaching. The maximum is 54.20 because of the synergism between the two substrates. The addition of metal ions and nutrient salts can greatly increase the leaching rate of gold, after the addition of appropriate amount of NaCl, The highest leaching rate of gold can reach 66.62%. Finally, by economic analysis, it is found that 1000 yuan of net profit can be obtained by using Pseudomonas fluorescens to extract gold from 1 ton waste circuit board. The most important thing is that microbial recovery of metals can achieve both economic and environmental benefits.
【学位授予单位】：青岛科技大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：X705;X172

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