Efficient photocatalytic mineralization of polymethylmethacrylate and polystyrene nanoplastics by TiO2/β-SiC alveolar foams

Household wastewaters contain microplastics and nanoplastics that end up in ecosystems because these pollutants are not filtered by current wastewater treatment plants. Therefore, there is a need for advanced removal technologies. Here, we tested the degradation of polymethylmethacrylate (PMMA) and polystyrene (PS) nanoparticles by photocatalysis with TiO2-P25/beta-SiC foams under UV-A radiation. We studied the effect of flow rate, initial pH and light intensity. Results show that about 50% of the carbon of polymethylmethacrylate nanobeads are degraded in 7 h at an irradiance of 112 W/m(2), a flow rate of 10 mL/min and an initial pH of 6.3. Degradation is faster at low pH (4-6) and low flow rate. 140-nm polystyrene degrades faster than 508-nm polystyrene.

Automated summary

Household wastewaters contain microplastics and nanoplastics that are not filtered by current wastewater treatment plants, requiring advanced removal technologies such as photocatalysis. Degradation of PMMA and PS nanoparticles using TiO2-P25/beta-SiC foams under UV-A radiation showed that lower pH and flow rate led to faster degradation, with 140-nm PS degrading quicker than 508-nm PS.