Continuous electricity from charged total dissolved solids in wastewater using a wood-based ion-selective power generator

Exploring the potential for secondary utilization of wastewater is a prudent strategy to achieve “take-make-use-reuse” circular economy. Taking advantages of wood’s hierarchical structure and large surface area, in this project, we fabricate surface-encapsulated anion-selective and cation-selective wood membranes (comprising up to 98% eco-friendly materials) through a two-step process: dip-coating with either positively charged 2(dimethylamino)ethyl methacrylate or negatively charged acrylic acid, followed by energy-efficient sunlight-induced polymerization. The output voltage and current of a single modified wood cell (20 × 20 × 3 mm 3 ) in modulated wastewater from flue gas desulfurization are 55 mV and 0.6 µA, respectively, tenfold higher than that of untreated wood cells. When five cells are connected in series, the output voltage reaches 0.27 V, sufficient to power simple electronic devices. This underscores its potential for scaling up and its viability for future applications in industrial power plants.