Nowadays, biomass-based materials are gaining prominence in environmental remediation issues due to their affordability, environmental friendliness, and ease of accessibility. Traditional adsorption is the most widely used strategy for removing textile dyes, heavy metals, and hazardous substances from water. Nickel is one of the most extensively studied metals in catalysis research, particularly in gas- and liquid-phase reactions. In this study, the aim was to remove nickel from an aqueous solution using Turkish coffee grounds. For this reason, adsorption experiments were carried out on coffee grounds, an agricultural waste, at room temperature, with different adsorbent amounts (0.05 and 0.07 g), adsorption times (15-60 min), and adsorbent types calcinated at several temperatures (300-700ºC) with a 0.4 g/L initial Ni(II) solution concentration and a 200 rpm shaking rate in a water bath. After that, based on UV-VIS results, Removal Efficiency (RE, %) and Adsorption Capacity (AC, mg/g) values were calculated. Because the coffee waste released its color to the adsorption media, absorbance values were read for both nickel-included and -excluded solutions. The maximum RE value was obtained as being 98% for 0.07 g of adsorbent that was calcinated at 300ºC after 30 min of adsorption at room temperature. In addition, the maximum AC value was found to be 284 mg/g for 0.05 g of adsorbent that was calcinated at 500ºC after 45 min of adsorption at room temperature. In the literature, maximum adsorption capacity values were in the range of 0.13-60.20 mg/g for several biomass-based adsorbents for Ni (II) removal [1]. So, it was thought that the biomass calcination procedure could be effective for Ni (II) removal from water. It is thought that this study creates an alternative green way to clean wastewater using biomass wastes.
[1] Shroff, K. A., & Vaidya, V. K. (2011). Kinetics and equilibrium studies on biosorption of nickel from aqueous solution by dead fungal biomass of Mucor hiemalis. Chemical Engineering Journal, 171(3), 1234-1245.
