A sustainable lignin-clay nano-absorbent for highly efficient methylene blue removal

Xiangju Fu; Lulu Cao; Shugang Zhang; Shanyu Meng; Yuechao Yang; Yuncong C Li; Guodong Liu; Zhaohui Tong

doi:10.1016/j.ijbiomac.2024.137030

A sustainable lignin-clay nano-absorbent for highly efficient methylene blue removal

Int J Biol Macromol. 2024 Oct 30;282(Pt 4):137030. doi: 10.1016/j.ijbiomac.2024.137030. Online ahead of print.

Authors

Xiangju Fu¹, Lulu Cao², Shugang Zhang³, Shanyu Meng⁴, Yuechao Yang⁵, Yuncong C Li⁶, Guodong Liu⁷, Zhaohui Tong⁸

Affiliations

¹ Agricultural and Biological Engineering, Institute of Food and Agricultural Sciences, University of Florida, Gainesville, FL 32611, USA; Department of Horticultural Sciences, Institute of Food and Agricultural Sciences, University of Florida, Gainesville, FL 32611, USA.
² National Engineering Laboratory for Efficient Utilization of Soil and Fertilizer Resources, National Engineering & Technology Research Center for Slow and Controlled Release Fertilizers, College of Resources and Environment, Shandong Agricultural University, Taian, Shandong 271018, China.
³ Agricultural and Biological Engineering, Institute of Food and Agricultural Sciences, University of Florida, Gainesville, FL 32611, USA; National Engineering Laboratory for Efficient Utilization of Soil and Fertilizer Resources, National Engineering & Technology Research Center for Slow and Controlled Release Fertilizers, College of Resources and Environment, Shandong Agricultural University, Taian, Shandong 271018, China. Electronic address: [email protected].
⁴ Agricultural and Biological Engineering, Institute of Food and Agricultural Sciences, University of Florida, Gainesville, FL 32611, USA.
⁵ National Engineering Laboratory for Efficient Utilization of Soil and Fertilizer Resources, National Engineering & Technology Research Center for Slow and Controlled Release Fertilizers, College of Resources and Environment, Shandong Agricultural University, Taian, Shandong 271018, China; Department of Soil and Water Sciences, Tropical Research and Education Center, Institute of Food and Agricultural Sciences, University of Florida, Homestead, FL 33031, USA.
⁶ Department of Soil and Water Sciences, Tropical Research and Education Center, Institute of Food and Agricultural Sciences, University of Florida, Homestead, FL 33031, USA.
⁷ Department of Horticultural Sciences, Institute of Food and Agricultural Sciences, University of Florida, Gainesville, FL 32611, USA. Electronic address: [email protected].
⁸ Agricultural and Biological Engineering, Institute of Food and Agricultural Sciences, University of Florida, Gainesville, FL 32611, USA; School of Chemical & Biomolecular Engineering, Georgia Institute of Technology, Atlanta, GA 30318, USA. Electronic address: [email protected].

PMID: 39486716
DOI: 10.1016/j.ijbiomac.2024.137030

Abstract

Water pollution caused by toxic dyes such as methylene blue (MB) has become a bottleneck for recycling or reusing enormous industrial wastewater. Designing a green and cost-effective bio-absorbent for the highly efficient removal of MB from wastewater is crucial but remains a great challenge. In this study, abundant, inexpensive, and environmentally benign lignin and bentonite were used as starting materials, and quaternary and amphiphilic lignin as a network macromolecule was designed to be inserted into the galleries of the stacked bentonite clay to prepare lignin-bentonite nanohybrids. The specific surface area of the modified nano-absorbent was significantly increased to 45.60 m²/g and owned a type II-like isothermal mechanism. The absorbent showed a maximum removal of MB of 99.7 % at neutral pH and room temperature with a maximum adsorption capacity of 822.22 mg/g, demonstrating the potential of an excellent adsorbent. The MB adsorption process fits well with both Langmuir and Freundlich isotherm models, the adsorption mechanism includes strong electrostatic attraction between absorbent and MB, and physical adsorption in a complicated monolayer and multiple macroporous structures. This study leverages the economic and environmental benefits of lignin and bentonite clay to prepare a cost-effective bio-absorbent for efficient removal of MB from aqueous solutions.

Keywords: Cost-effective bio-adsorbent, adsorption mechanism; High-efficiency MB removal; Lignin-clay nanohybrid.