The Improvement of Heavy Metals Removal by Wood Membrane in Drinking Watertreatment: Comparison with Polymer Membrane and Associated Mechanism

Abstract

The application of commercial membranes is limited by the secondary pollution suchas the usage of toxic chemicals for the membrane preparation and the disposal ofaged membranes. Therefore, the green and environmentally friendly membranes areextremely promising for the sustainable development of membrane filtration in watertreatment. In this study, the comparison of wood membrane with the pore size of tensmicrons (µm) and polymer membrane with the pore size of 0.45 µm was made to studythe heavy metals removal in drinking water treatment by gravity-driven membrane(GDM) filtration system, and there was an improvement in the removal of Fe, Cu andMn by wood membrane. The cellular structure of fouling layer for wood membranemade the retention time of heavy metals prolonged in contrast to the cobweb structureof polymer membrane. The carboxylic group (-COOH) content of fouling layer for woodmembrane was greater than that for polymer membrane. Additionally, the populationabundance of heavy metal-capturing microbes on the surface of wood membrane washigher compared with polymer membrane. The wood membrane provides a promisingroute to producing facile, biodegradable and sustainable membrane as a greenalternative to polymer membranes in heavy metal removal from drinking water.

Keywords: wood membrane, Drinking water treatment, GDM filtration technology, Heavy metals removal, polymer membrane