PMDA-modified biosorbents for enhancement adsorption of basic magenta

In this study, waste materials such as beer yeast and sugarcane bagasse (BY and SB) were modified with pyromellitic dianhydride (PMDA) to enhance their adsorption capacities for cationic dye: basic magenta (BM). Adsorption factors such as initial concentration, contact time, ion strength were investigated. FTIR demonstrated that a large number of carboxyl groups (–COO−) were introduced onto the surface of the biosorbents. The adsorption capacities of the modified beer yeast (MBY) and the modified sugarcane bagasse (MSB) for basic magenta were 528.1 and 736.5 mg g−1, respectively, which were 3.3 and 7.6 times greater than those obtained on the unmodified beer yeast (UBY) and unmodified sugarcane bagasse (USB). The adsorption could be finished within 630 min for MBY and 645 min for MSB, respectively. Ion strength experiments showed that it had little effect on the adsorption of BM when the concentration of co-ion (K+) was lower than 0.1 mol L−1. Additionally, the desorption ratio of BM from MBY and MSB were 94.8 and 89.9 %, respectively, by using the appropriate eluent. These efficient biosorbents have potentials for application in wastewater treatment.