Synthesis of CaWO4-biochar nanocomposites for organic dye removal

Abstract Wastewater contaminated by organic dyes is a serious environmental concern. Absorption and photodegradation are two of the most common methods for organic dye molecule removal in wastewater. In this work, we develop a facile method to synthesize CaWO 4 -biochar nanocomposites by co-precipitation method with calcium chloride and sodium tungstate in the presence of commercial biochar. The prepared CaWO 4 -biochar nanocomposites combine the adsorption effect from biochar and photodecoloration of dyes from CaWO 4 nanoparticles. The influence of the ratio of CaWO 4 to biochar on the organic dyes including rhodamine (RhB) and methyl orange (MO) is studied. The improved organic dye removal capacity of the CaWO 4 -biochar composites compared with bare biochar is obtained. The synthesis of CaWO 4 -biochar composites developed in this work provide a facial technique to improve the biochar removal abilities, which can be used in industrial wastewater treatment to increase the organic dye removal efficiency.