Synthesis of ultralight chitosan/activated biochar composite aerogel globules for ketoprofen removal from aqueous solution

•The ultralight chitosan/biochar composite aerogel globules were synthesized.•The sorption kinetics, isotherms and mechanism of KTP onto globules were studied.•Factors affecting sorption performance and property of globules were discussed. A novel non-template method was used to prepare ultralight composite aerogel globules that were exploited for the removal of anti-inflammatory drug ketoprofen (KTP) from aqueous solution. The composite aerogel globules were synthesized by freeze-drying and characterized with FESEM, BET, FTIR, XRD and Zeta potential. Swelling behavior of these aerogel globules was strongly affected by the solution pH. The results showed that the presence of 10% activated biochar (ABC) in chitosan (CS), which was named CS-ABC2, was the most desirable aerogel globules as it had high mechanical property and remarkable sorption performance. The sorption kinetics and isotherms of KTP onto composite aerogel globules were studied in detail. In addition, the effects of ion strength and regeneration on sorption performance were investigated, indicating decent environment tolerance, complete recovery rate and excellent reusability of the composite aerogel globules. The composite aerogel globules also exhibited other outstanding advantages such as biodegradability, economy and ease of separation.