Deep removal of organic matter in glyphosate contained industrial waste salt by dielectric barrier discharge plasma

Abstract

The cyclic utilization of industrial waste salt can not only solve its environmental pollution problem but also reclaim the available resources. The deep removal of organic pollutants is one of the main challenges for the reuse of waste salt. In this study, dielectric barrier discharge (DBD) plasma is used to remove organic pollutants from simulated industrial waste salt containing glyphosate. Experimental results indicate that DBD plasma can reduce deeply the content of organic matters in waste salt. The decrease of total organic carbon (TOC) is affected by discharge voltage, gas flow rate, initial TOC and water content. For the simulated waste salt with an initial TOC content of 48.1 mg/kg, the finial TOC content decreased to 9.5 mg/kg after a 25 min DBD plasma treatment at the discharge voltage of 14.0 kV, the water content of 10%, and the air flow rate of 0.5 L/min. The maximum energy efficiency of TOC removal is 116.5 mg/(kW.h). A reaction mechanism of refining of the waste salt was proposed based on the detection and analysis of the degradation intermediates and mineralized products. The results of this study show that non-thermal plasma can be used to refine the organic matter contained waste salt with no production of waste water, which has a good prospect of research and application.