A integrated mechanical vapor compression enrichment system of radioactive wastewater: Experimental study, model optimization and performance prediction

Abstract

Evaporation technology has unique advantages in the enrichment of radioactive ions, which can deal with the high concentration of radioactive wastewater. A integrated mechanical vapor compression (MVC) enrichment system with high efficiency filter was proposed and studied experimentally for radioactive wastewater, whose decontamination factor was 37107.1 for Co2+, 2741.3 for Sr2+, and 52545.5 for Cs+, which saved energy by 76.7–84.3% and operation cost by 72.0–81.0% when compared to the conventional single effect (SE) evaporation system. Exergy destruction and efficiency of the single screw compressor were 7.26 kW and 34.0%, respectively, which should be prioritized for improvement. Mathematical models based on both the heat transfer coefficient (HTC) and coefficient of performance (COP) were established and optimized experimentally, the ideal running parameters were 90–110 kPa for evaporating pressure, 8.5–11.5 °C for heat transfer temperature difference, 1.50–1.60 for compression ratio and 2.0–4.0 kPa for filtration pressure difference, respectively. It will supply the theoretical and data basis for development and design of MVC enrichment system of radioactive wastewater.