Section 1 : Introduction

This year, we have been working at solving the problem of recycling rare earth elements in the mine drainage, and then designed the REE Miner program. Nowadays, our country has already had some methods on disposing drainage, such as chemical precipitation method and microbiological disposal method. But there are still some inadequacies in recycling REE in drainage, which will cause the waste of non-renewable REE resource to some extent. Because of comprehensive environment problems in mining and industrial processing, mining REE has been suspended in some area of China for several years. Recycling REE from drainage would improve resource utilization rate. Therefore, to achieve the target of recycling and enriching REE, we designed and made corresponding synthetic biology system and hardware device.

Section 2 : Proposed end user

REE disposal plants need to dispose a large amount of mine drainage, but few of them recycle REE from drainage. Current methods frequently-used are chemical oxalic acid precipitation and ammonium sulfate replacement, which will pose a threat to the environment in the long run and be disadvantageous to the sustainable development. Simultaneously, the recycling rate of REE is limited through using chemical methods. For every 54 tons of REE produced, 1 ton of REE will be wasted.

Our proposed end users are REE mining plants and drainage disposal plants, which need to recycle REE from drainage to reach higher resource efficiency. Meanwhile, using our product will be more environmental-friendly, improve resource utilization rate and reduce the harm of chemical reagents on workers’ health.

Section 4 : How to use our products?

REE Miner will be applied to the drainage discharging process in plants. Put our device in the drainage, and the drainage will inflow from the hardware inlet and stay for a while. Through releasing drainage layer by layer, it can achieve adsorbing REE repeatedly, and improve adsorption rate. We have simulated and tested the activity of the target protein under the working conditions. At pH=6.5, the REE adsorption rate is up to 84%, which illustrates that our engineering bacteria are still highly active in real working environment. With the hardware we designed, we can achieve multilayer adsorption. We estimate it will reach 95% adsorption rate.

Section 5 : Safety

In order to ensure bio-security, we have placed bacterial filter membrane at the hardware entrances and exits while installing sterilization room on the exits, as a result we can guarantee our engineering bacteria not to escape from the device.

Section 6 : Challenges

In the real practice, we still need to overcome some challenges. Firstly, there is no carbon source in the working conditions, so our engineering bacteria cannot grow in working environment directly, and they need to be incubated in advance instead. Secondly, the drainage in some plants is produced with high content of inorganic salt ions, where our engineering bacteria cannot work. Thirdly, there are some fluctuations in the adsorption rate, and we cannot make sure all the engineering bacteria would reach the highest adsorption rate while working. Although there are still some challenges, we have already had a more detailed plan, which can improve the adsorption rate as much as possible under the premise of ensuring bio-security.