Application of UVA-LED based photocatalysis for plywood mill wastewater treatment

• Feasibility of LED-based photocatalytic reactor was studied.
• Optimal operational conditions were determined for model compounds.
• Promising results were obtained for treatment of real wastewater.

The batch mode UVA-LED photocatalytic reactor with recirculation was tested for formic acid (0.22 mM) and phenol (0.1 mM) degradation using commercially available titanium dioxide. Decomposition of model molecules was monitored by means of high pressure liquid chromatography (HPLC), total organic carbon analyzer (TOC) and chemical oxygen demand (COD). Apparent quantum yields for formic acid and phenol were estimated to be 0.8% and 0.98%, respectively. Also, plywood mill effluent treatment was performed using chosen reactor. Primary degradation of tannic acid, as well as TOC and COD removal were monitored in the course of an experiment. About 72% and 60% of COD and TOC removal was achieved, respectively, after 60 min of irradiation at TiO2 loading 0.5 g L−1. The evolution of average oxidation state of carbon atoms was estimated for plywood mill wastewater.