Adsorptive Removal of Nickel from Aqueous Solution by Palm Seeds-based Magnetic Biochar

Here, the possibility of using biomass wastes such as palm seed as a suitable precursor for the preparation of magnetically responsive adsorbent was explored. Magnetic biochars (MB) were prepared from raw palm seed in the presence of iron oxide (Fe3O4) particles and utilized for adsorption of nickel. The thermal decomposition processes of the adsorbents were determined by thermogravimetric analysis. The physical structure and textural characteristics of the adsorbents were investigated. The effects of adsorption parameters, including pH, adsorbent dosage, temperature, interfering ions and contact time were investigated. The results showed that the magnetic biochar exhibited high sorption capacity, excellent dispersion and convenient separation after spent. The relationship between the MB and the pollutant (Ni2+) was established to follow Langmuir model, described well by pseudo-second-order kinetic and intraparticle diffusion played an important role in the sorption process. 27.8 mg/g was obtained as the maximum nickel uptake. The values of thermodynamic parameters revealed that the sorption process depended on the temperature of the medium, was spontaneous and endothermic in nature. Lastly, the magnetic biochar was regenerated via a simple technique and reuse with no significant loss in activity, suggesting that MB is technically and economically efficient. Keywords: Magnetic biochar, palm seed powder; nickel (II) ions, adsorption