Preliminary investigation of mixed adsorbents for the removal of copper and methylene blue from aqueous solutions

摘要

With most recent studies being focused on the development ofadvanced chemical adsorbents, this paper investigates the possibility ofusing two natural low-cost materials for selective adsorption. Multiadsorbentsystems containing tea waste and dolomite have been tested fortheir effectiveness in the removal of copper and methylene blue fromaqueous solutions. The effects of contact time, solution pH andadsorption isotherms on the sorption behaviour were investigated. TheLangmuir and Freundlich isotherms adequately described the adsorption ofcopper ions and methylene blue by both materials in different systems.The highest adsorption capacities for Cu and MB were calculated as 237.7at pH 4.5 and 150.44 mg.g‒1 at pH 7 for DO and TW+DO respectively. Teawaste (TW) and dolomite (DO) were characterized by Fourier transforminfrared spectroscopy, scanning electron microscopy and Energy dispersiveX-ray analysis. The removal of Cu and MB by dolomite was mainly viasurface complexation while physisorption was responsible for most of theCu and MB adsorption onto tea waste. Identifying the fundamental mechanisms and behaviour is key to the development of practical multi-adsorbent packed columns.