Highly porous carbon with rich inherent groups for ultrahigh adsorption of organic dyes from wastewater

Activated carbon from renewable biomass or its waste to purify various dyeing wastewater from textile industry is highly desired. In this work, porous activated carbon was prepared by using silk waste as precursor via a simple one-step carbonization process. The obtained SWC-1-800 had ultrahigh adsorption for anionic dye AR73 and cationic dye MB owing to its ultrahigh specific surface area (2774 m(2) g(-1)) and rich functional groups. SWC-1-800 had an increased adsorption capacity reaching 1310 and 928 mg g(-1) for AR73 and MB respectively as the initial concentration up to 1000 mg L-1. Moreover, the adsorption capacity was stable under a wide range of Na+ and SDS concentration. By adjusting the temperature and pH value, the maximum adsorption capacity reached 1337 and 1000 mg g(-1) for AR73 and MB respectively, keeping the removal rate of AR73 and MB more than 80 % after 5 adsorption cycles. Besides, SWC-1-800 demonstrated quite good adsorption ability for many other kinds of dyes, which adsorption capacity as high as 1998 mg g(-1) (Rh B). The adsorption mechanism was further proposed according to the structural characteristics, inherent functional groups and adsorption properties. Using silk waste-derived carbon to effectively absorb the harmful dyes in the wastewater shows dual value for cleaner production via a "waste-waste to clean products" model, which has great application potential in dyeing wastewater purification.