Selective removal of anionic dyes in single and binary system using Zirconium and iminodiacetic acid modified magnetic peanut husk.

A novel adsorbent (PN-Fe3O4-IDA-Zr) was developed from the chemical modification of peanut husk (a low cost material) with Fe3O4, iminodiacetic acid (IDA) and zirconium (Zr) and its efficacy for the sequestration of wastewater assessed using Alizarin red (AR) and Acid chrome blue K (AK) as model pollutants. To elucidate the characteristics of the formed adsorbent, analytical techniques such as the Bruauner-Emmet-Teller (BET) method, X-ray photoelectron spectroscopy (XPS), Fourier-transform infrared (FTIR) spectroscopy, X-ray diffractive spectroscopy (XRD) and vibrating sample magnetometer (VSM) were applied. Results from these studies confirmed the formation of a crystalline mesoporous adsorbent with surface properties which enhanced its usefulness. From the adsorption studies, it was observed that factors such as pH, salts, temperature and contact time influenced the uptake of the anionic dyes. The maximum monolayer capacity of PN-Fe3O4-IDA-Zr for AR was 49.4 mg g-1 (at 313 K) and was well fitted by the Langmuir model with the chemisorption process being the dominant reaction mechanism. In binary systems, PN-Fe3O4-IDA-Zr exhibited higher affinity for AR as compared with AK. The significant removal efficiency exhibited by this novel adsorbent as well as other unique features such as easy retrieval and high regeneration promotes its prospects as an adsorbent for practical wastewater remediation processes.