Dry fruit shell-derived biochar increases biosorption potential and detoxification of organic pollutants for land safety

The increase in water pollution and land degradation ultimately reduces the supply of clean water for the growing population. Biochar produced from dry fruit shells is an effective adsorbent for organic pollutants. It can help reduce soil contamination and water pollution, making it an important option for land safety. For this experiment, dry fruit shell biochar was produced and activated chemically with 1 M KOH to increase the pollutants' removal efficiency. The efficiency of biochar as an adsorber of pollutants was assessed by characterizations of scanning electron microscope, Fourier transform infrared, and X-ray diffraction (XRD) techniques. The peak of almond shell biochar was observed between 1033 and 1068 cm-1, while in pistachio, it was observed at 1458-1446 cm-1. Data extracted from XRD showed that most peaks were shifted after activation. For example, in walnut shell biochar, the peak shifted from 11 degrees to 18 degrees after biochar activation. The highest pollutant removal efficiency, such as 92%, 90%, and 87%, was observed in walnut shell biochar at 1, 2, and 3 mLL-1 adsorbate concentration, respectively. Pistachio shell biochar was most effective in the presence of the chemical activator to remove toluene and phenol organic contaminants. An increase in adsorbate concentration decreased the removal efficiency from 50% to 46% in activated almond shell biochar, 58% to 55% in activated pistachio shell biochar, and 55% to 54% in activated walnut shell biochar by 1 gL-1 of adsorbent. Kinetic and equilibrium data with different applied models established that the adsorption process was favorable, and models were fitted to the experimental setup. Biochar prepared from different dry fruit shells and their optimum activation can be used as bio-sorbent for pollutants' removal and hence improved land development for agriculture and other industrial purposes.