Efficient Coacervate Extraction of Cationic Industrial Dye from Wastewater

Effluent wastewater containing dyes from textile, paint, and various other industries have long posed environmental issues. Functional Nano materials offer new opportunities to treat these effluent wastes in unprecedentedly high efficient and facile fashion due to their large surface area-to-volume ratio. In this work, we explore a new organic-inorganic hybrid nanomaterial based on the complexation of zwitterionic polyampholyte with anionic polyoxometalate (POM) nanocluster to demonstrate coacervate extraction of cationic dye, methylene blue (MB) as a model waste from its salted aqueous solution. MB wastewater samples were prepared at a concentration of 0.2 g/L and were used to subject the hybrid complexes to multiple rounds of extraction to determine the upper limit of adsorption of the material. Efficiency of coacervated complexes at varied POM concentrations and molar ratio to polyampholyte were measured using a UV-vis spectrophotometer. Our polyionic complexes exhibited ~99% removal efficiency for all initial MB wastewater samples with measured adsorption capacity as high as 352 mg/g, indicating extremely high efficiency. Our study also suggested that coacervate extraction could be a facile and robust method for ionic selective wastewater treatment with parameters such as temperature and pH showing no influence on removal efficiency.