Research on High Flux Direct Contact Membrane Distillation Technology

Abstract

The effects of membrane materials, membrane module structure and membrane distillation operation parameters on the performance of direct contact membrane distillation were investigated by using strontium chloride solution with Sr2 + concentration of 1g/L as test solution. The results showed that the flux of PTFE is the largest, PVDF is the second, PP is the smallest, and the rejection rate of PTFE decreases rapidly with the increase of running time, which indicated that PTFE is easy to be fouled, while PVDF is a better membrane material; When the packaging fraction of membrane module increases, the membrane flux decreases, but the water yield per unit time increases. Considering the economy and treatment efficiency, it is recommended to select the membrane module with packaging fraction of 11.42%; the increase of feed flow rate and temperature is beneficial to the increase of flux in DCMD process. The rejection rate is almost unaffected by the membrane module structure and operating conditions, and remains above 99.9%. This study is helpful to provide research direction for improving membrane distillation flux, and provide theoretical reference for membrane distillation technology to treat practical radioactive wastewater.