Innovative benign-to-design functionalized adsorbents from biomass for rapid azo-dyes separation

摘要

Highly toxic dye wastewater constantly threatens ecological balance and human health, resulting in that efficient separation of dye wastewater becomes increasingly urgent. In this study, novel PDA@CMCS microspheres (average specific surface area: 16.28 m(2) g(-1)) were successfully synthesized by two-step successive route. As-prepared PDA@CMCS microspheres were characterized by using SEM, FTIR and EDS. The amino content of PDA@CMCS microspheres were further determined by linear titration. Methyl orange (MO) was selected as the representative of azo-dyes to evaluate the adsorption properties of PDA@CMCS microspheres. Various influencing factors such as grafting time, initial solution pH, inorganic anions, and adsorbents dosage were analyzed to obtain the optimal MO adsorption condition. Under this condition, the maximum adsorption capacity of PDA@CMCS microspheres towards MO was up to 207.469 mg g(-1). The adsorption kinetics was better described by the pseudo-second-order model, while the adsorption isotherms of PDA@CMCS fitted the Langmuir model well. The MO adsorption by PDA@CMCS microspheres was dominated by electrostatic attraction, accompanied by hydrogen bonding. Furthermore, the excellent mechanical strength and the stable regeneration property of PDA@CMCS microspheres were also verified. Therefore, novel PDA@CMCS microspheres could be a highly promising candidate for dye wastewater treatment.