Non-thermal plasma degradation of dye wastewater assisted by reverse osmosis process through interfacial mass transfer enhancement

A two-stage system of dye wastewater treatment was proposed, containing reverse osmosis (RO) process and nonthermal plasma (NTP) degradation. The dye wastewater was concentrated by reverse osmosis to enhance the mass transfer of organic dye from the falling film to the reaction interface, promoting dye removal and energy yield of the plasma degradation. The effects of the methylene blue concentration (100-500 mg center dot L-1), flow rate, and the discharge power of plasma (40-100 W) on the methylene blue removal and the energy yield of the NTP mode were investigated. At the removal of 45%, the energy yield of RONTP mode was 1198.0 mg center dot kWh-1, which was 2.36 times than NTP mode. 8 degradation intermediates were detected by LC-MS, which mass/charge ratio were in the range of 80-400. This investigation provides a guidance to improve the energy yield of dye wastewater by plasma through mass transfer enhancement.