Difunctional MOF-EDTA modified wood membrane for efficient water purification

The environmental pollution caused by the discharge of oily wastewater and printing and dyeing wastewater is becoming more and more serious. Therefore, it is necessary to find an efficient method to separate oil/water emulsions and remove organic dyes from water simultaneously. However, the traditional separation membranes are usually very expensive and easy polluting the environment. Therefore, how to prepare high-efficiency separation membrane from low-cost, green renewable materials remains a huge challenge. In this study, ethylenediaminetetraacetic acid (EDTA) modified metal–organic framework (MOF-808) nanoparticles were introduced into the wood substrate to construct a 3D wood/MOF-808-EDTA membrane with efficient water purification performance (oil/water emulsion separation and organic dye removal). Due to the introduction of hydrophilic MOF-808-EDTA nanoparticles, this novel membrane can effectively separate stable oil-in-water emulsions and remove organic dyes from water. The prepared wood/MOF-808-EDTA membrane has a high separation efficiency (more than 99.9 %) and permeation flux (1698 ± 15.85 L·m −2 ·h −1 ). The removal efficiency of organic dyes is more than 94 % with the permeation flux 1360 ± 2.54 L·m −2 ·h −1 . More importantly, the separation efficiency (oil/water emulsion) remained above 99.9 % and the dye removal efficiency was still above 90 % after 10 cycles. Additionally, the wood/MOF-808-EDTA membrane also has good mechanical/chemical stability and anti-fouling properties. This work opens a new approach for the development of functional biomass material membranes for sewage purification.