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 CaWO4-biochar nanocomposites by co-precipitation method with calcium chloride and sodium tungstate in the presence of commercial biochar. The prepared CaWO4-biochar nanocomposites combine the adsorption effect from biochar and photodecoloration of dyes from CaWO4 nanoparticles. The influence of the ratio of CaWO4 to biochar on the organic dyes including rhodamine (RhB) and methyl orange (MO) is studied. The improved organic dye removal capacity of the CaWO4-biochar composites compared with bare biochar is obtained. The synthesis of CaWO4-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.