Microwave-assisted synthesis of β-cyclodextrin functionalized celluloses for enhanced removal of Pb(II) from water: Adsorptive performance and mechanism exploration

Herein, beta-cyclodextrin (beta-CD) was efficiently grafted onto rice husk-based celluloses using different crosslinking agents of epichlorohydrin ( EPI) and glutaraldehyde (GA). By feat of microwave irradiation, the functionalization procedure was completed in 17 min, and the synthesized RH PI/W beta-CD and RH A/W beta-CD exhibited fast adsorption equilibrium for Pb(II) within 20 min, excellent monolayer adsorption capacities of 216.06 and 279.08 mg g(-1) across an extensive pH scope of 3.0-6.0, unaffected affinity to Pb(II) during the existence of coexisting ions, superior reusability with over 81% and 87% of Pb(II) uptake sustained for four adsorptiondesorption cycles. Thermodynamic parameters implied that the uptake process of Pb(II) occurred spontaneously (-Delta G(0)) with an endothermic characteristic (+Delta H-0). Furthermore, electrostatic attraction and complexation were demonstrated to enhance the Pb(II) uptake onto the RH EPI/MW beta-CD and RH GAMW beta-CD. In fix-bed columns, these two adsorbents also efficiently eliminated Pb(II) under various flow rates with experimental breakthrough curves well simulated by Thomas and Yoon-Nelson models. Significantly, the RH EPI MW beta-CD and RH GA/W beta-CD could effectively purify acid battery effluent containing Pb(II) formeeting regulatory requirement. Overall, the fast fabrication, excellent adsorption and recycling performance facilitate the development of tailored adsorbents for Pb (II) elimination in wastewater. (C)2020 Elsevier B.V. All rights reserved.

Automated summary

In this study, beta-cyclodextrin was efficiently grafted onto rice husk-based celluloses using microwave irradiation, leading to fast adsorption equilibrium and superior reusability for Pb(II) removal. The synthesized adsorbents exhibited excellent adsorption capacities and could effectively purify acid battery effluent containing Pb(II), showing great potential for tailored adsorbents development in wastewater treatment.