Salt-dye separating nanofiltration membrane as well as preparation method and application thereof

Abstract

The invention discloses a salt-dye separating nanofiltration membrane as well as a preparation method and application thereof. According to the preparation method, an ultrafiltration membrane is used as a basement membrane; 2,2'-benzidinedisulfonic acid is used as a water-phase monomer; trimesoyl chloride is used as an organic-phase monomer to be dissolved in an organic solvent; a polyamide selecting layer is prepared and obtained through a water phase-organic phase interfacial polymerization method. According to the preparation method, the nanofiltration membrane with suitable charge performance and an appropriate membrane aperture is obtained through the regulation of monomer concentration, polymerization time, pH (potential of Hydrogen) and the like; by means of a Donnan effect and aperture sieving action, a dye and an inorganic salt are subjected to separation treatment; while an organic macromolecular dye can be effectively intercepted, ions of the inorganic salt are enabled to pass through to a greater extent; in comparison with a conventional commercial membrane, the water consumption is greatly reduced; the operating time is also obviously shortened. In addition, the nanofiltration membrane prepared by the preparation method has the advantages of being higher in mechanical strength, better in stability and easy to wash, and the like; the treatment of salt-dye wastewater can be effectively realized.

Description

technical field [0001] The invention belongs to the technical field of nanofiltration membrane preparation, and relates to a salt-stained separation nanofiltration membrane, a preparation method and application thereof. Background technique [0002] Industrial wastewater has become the main source of water pollution, especially printing and dyeing wastewater. The data shows that it takes 200-350m to produce 1t of dye 3 Pure water, resulting in a large amount of printing and dyeing wastewater, has caused great harm to the environment. Printing and dyeing wastewater has high salinity (NaCl: 6.0wt%, Na 2 SO 4 : 5.6wt%), high COD, high chroma and other characteristics, the recycling of dyes and salts can not only significantly reduce the preparation of dyes and the waste of salt, but also greatly reduce the pollution and harm of wastewater to the environment, but many printing and dyeing wastewater treatment Processes (such as adsorption, sedimentation, biodegradation, oxida...

AI Technical Summary

Problems solved by technology

Lin Jiuyang et al. used commercial membranes Sepro NF 6 and Sepro NF 2A to separate mixed solutions of different dyes (DR80, DR 23, CR) and salts (NaCl), and found that these commercial membranes had good retention of dyes ( 99.9%), but the penetration capacity of salt is average, and it is easy to cause concentration polarization, which leads to serious water consumption and energy consumption in the process of treatment (Lin, J.Y et.al.J.Memb.Sci.2015)

Wang Zhan et al. used loose nanofiltration membranes to separate salt-stained wastewater, and the interception of methylene blue and Congo red reached 97.3% and 97.1%, which has good dye retention capacity, but the flux in the separation process is small and takes a long time , membrane cleaning and only low concentration dyes were studied (Wang, Z et.al.J.Memb.Sci.2016)

Images