High efficiency selenium recovery via reactive evaporation driven by wood-based evaporator

Selenium is a vital trace element for living organisms but also a contaminant released from industrial runoff. Conventional methods of removing selenium from solutions 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 that offers a one-pot solution to simultaneously reduce wastewater volume in tailings ponds and recover selenium. The wood-based evaporator achieves a rapid evaporation rate of 2.6 LMH and 96 % selenium recovery by converting whole solar energy spectrum for photothermal water evaporation and photocatalytic selenium 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. Synopsis The wood-based reactive evaporator leverages lignocellulosic porosity and surface functional groups to evaporatively concentrate wastewater and redox-capture selenium at 96 % recovery, markedly reducing effluent volume.