Effect of salinity and temperature on treatment of concentrated wastewater from RO by FO-MD

International Conference on Energy Engineering and Environmental Protection 2017

能源学;生态环境科学

Zhou, Yingru^1 ; Huang, Manhong^1 ; Deng, Qian^1

College of Environmental Science and Engineering, State Environmental Protection Engineering Center for Pollution Treatment, Control in Textile Industry, Donghua University, Shanghai

201620, China^1

关键词: Concentrated wastewater;    High salinity wastewaters;    Membrane distillation;    Permeation fluxes;    Removal rate of cods;    Salt concentration;    Stable operation;    Total dissolved solids;   

Others  :  https://iopscience.iop.org/article/10.1088/1755-1315/121/3/032001/pdf
DOI  :  10.1088/1755-1315/121/3/032001

学科分类：环境科学（综合）

来源: IOP

【 摘 要 】

In this study the appropriate temperature of the membrane distillation (MD) hot side (the permeation flux of MD was controlled by adjusting the hot side temperature) was selected according to the water flux of FO process so that the water transfer rate on both sides of FO and MD was consistent and the FO-MD process could be stable operation. When the salt concentration of feed solution was 30, 55, 80 and 100 g/L, the desalination rates changed little, which were 99.1%, 98.4%, 98.9% and 98.7%, respectively. The removal rate of COD was 93.8%, 94.2%, 91.6% and 92.7% which also changed little like the desalination rates. The removal rate of chromaticity increased with the increase of salinity, which attained 96.6%, 97.0%, 97.2% and 97.9%, respectively. This study proved that salinity of the feed solution affected little on the removal rate of contaminants but great on the water flux, with the increase of salinity from 30 to 100 g/L, the water flux was 6.05, 4.81, 4.33 and 3.87 LMH with the appropriate temperature (67.5±0.5, 64.5±0.5, 62.5±0.5 and 60.5±0.5 °C) of MD hot side. In a word, FO-MD was first used to treat the high salinity RO water with over 30 g/L total dissolved solids (TDS), FO-MD was a promising new process for high salinity wastewater treatment, and the hybrid system can solve the problem of lower draw solution concentration, and the high-quality production water will be obtained directly by this hybrid system with low membrane fouling tendency.