Functionalized magnetic biocomposite based on peanut husk for the efficient sequestration of basic dyes in single and binary systems: Adsorption mechanism and antibacterial study

Abstract

In this study, an efficient and highly recyclable magnetic biocomposite based on peanut husk (labeled as MPN-Cit) was synthesized for the adsorption of Methylene Blue (MB) and Rhodamine B (RhB) dyes in single and binary systems. MPN-Cit was found to be a crystalline magnetic adsorbent with mesoporous structure and acidic functional groups based on the results obtained from the characterization studies carried out. Adsorption study via the batch method showed that the maximum monolayer adsorption capacity of MPN-Cit for MB and RhB was 245 and 57.3 mg g−1 at 303 K, respectively. The chemisorption process dominated the uptake of MB onto MPN-Cit whereas the physisorption process largely dominated by the hydrogen bonding was the major mechanism underlying the uptake of RhB. MPN-Cit in the binary system exhibited greater affinity towards MB as compared with RhB in all of the competitive systems and in actual wastewater. Another significant feature of this study is the ability of the loaded adsorbents (i.e. MPN-Cit-MB and MPN-Cit-RhB) to exhibit antibacterial properties; which our search shows has not been fully investigated. These results coupled with the high recyclability of MPN-Cit for further adsorption cycles and its ease of separation enhance its practical prospects.