RESEARCH ARTICLE Iminodiacetic acid functionalized magnetic peanut husk for the removal of methylene blue from solution: characterization and equilibrium studies Aaron Albert Aryee 1 & Farid Mzee Mpatani 1 & Alexander Nti Kani 1 & Evans Dovi 1 & Runping Han 1 & Zhaohui Li 1 & Lingbo Qu 1 Received: 11 March 2020 /Accepted: 9 July 2020 # Springer-Verlag GmbH Germany, part of Springer Nature 2020 Abstract A novel adsorbent PN-Fe 3 O 4 -IDA was developed by the chemical modification of magnetic peanut husk with iminodiacetic acid (IDA) and its efficacy for the sequestration of cationic dyes assessed using methylene blue (MB) as a model. This modification process enhanced the adsorption capacity of peanut husk as an adsorbent for dye sequestration and at the same time greatly minimized the adverse effects associated with its use in the pristine state. Results from the batch adsorption studies indicated that the uptake of MB onto PN-Fe 3 O 4 -IDA increased with MB concentration, contact time, temperature and pH whereas it decreased in the presence of some common salts. The pseudo-second-order kinetic model was observed to best describe the adsorption process which may greatly be influenced by the intra particle diffusion mass transfer. A maximum monolayer adsorption capacity of 43.5 mg g -1 was observed at 313 K according to the Langmuir model. There was good property of regeneration for MB-loaded PN-Fe 3 O 4 -IDA. Based on these results, as well as other unique features such as easy separation and preparation under benign environmental conditions, PN-Fe 3 O 4 -IDA exhibits great potential for the removal of MB and other cationic pollutants in practical applications with easy separation from solution using external magnet. Keywords IDA-modified magnetic peanut husk . Adsorption . Methylene blue . Regeneration Highlights • Iminodiacetic acid functionalized magnetic peanut husk (PN-Fe 3 O 4 -IDA) was synthesized. • PN-Fe 3 O 4 -IDA possessed mesoporous structure and operational convenience. • PN-Fe 3 O 4 -IDA exhibits excellent adsorption capacity and easy recovery from solution. • PN-Fe 3 O 4 -IDA can be regenerated using HCl (0.1 mol L -1 ) with a high efficiency of about 86 %. Responsible Editor: Tito Roberto Cadaval Jr * Runping Han rphan67@zzu.edu.cn * Zhaohui Li zhaohui.li@zzu.edu.cn * Lingbo Qu qulingbo@zzu.edu.cn Aaron Albert Aryee a.niiayi@yahoo.com Farid Mzee Mpatani papilampatani@gmail.com Alexander Nti Kani mykani@yahoo.com Evans Dovi evansdovy@gmail.com 1 College of Chemistry, Zhengzhou University, No 100 of Kexue Road, Zhengzhou 450001, People’s Republic of China Environmental Science and Pollution Research https://doi.org/10.1007/s11356-020-10087-6