Wood Reactive Evaporator for Selenium Recovery
We developed and tested a wood-based reactive evaporator, which reduces the volume of the wastewater and recovers selenium at the same time.
Selenium is a vital trace element that is essential to all living organisms, but it has emerged as a water treatment concern in various industries such as mining, oil refining, and power generation. However, conventional methods of removing selenium are complex and expensive due to low discharge limits and large volumes of wastewater. In this study, we developed and tested a wood-based reactive evaporator, which reduces the volume of the wastewater and recovers selenium at the same time. The unique properties of the wood evaporator allow for a fast evaporation rate of 2.6 LMH and a selenium recovery efficiency of 96%. This is achieved by converting 95% of solar energy into thermal energy for water evaporation and concentrate selenium to the surface, while using the remaining 5% for photocatalytic reduction. Additionally, the acidic nature of the wood provides a preferred pH environment for selenium reduction even with alkaline water sources, and the photocatalytic reaction can be sustained without additional hole scavengers. Furthermore, our evaporator has shown success in recovering other heavy metals and can be adjusted for selectivity.