Synthesis and Application of Modified Orchard Waste Biochar for Efficient Scavenging of Copper from Aqueous Solutions

Abstract

Efficient adsorbents were fabricated by modifying the orchard waste biochar (BC) to produce zero-valent iron composited BC (BC/Fe0) and phosphorus embedded BC (BC/P). The efficacy of these adsorbents for copper [Cu(II)] removal from aqueous media was investigated via pH, kinetics, and adsorption batch trials. The solution pH 7 was found optimum for the highest Cu(II) removal. Elovich model was fitted well to the Cu(II) kinetics adsorption and higher initial sorption rate 79.44, 75.71, 72.28, 61.60\xa0mg\xa0g−1\xa0min−1 for BC/Fe0, BC, AC, and BC/P, respectively, was observed than other kinetic models. Langmuir, Freundlich, and Redlich–Peterson isotherm models were applied to the experimental data and Langmuir model fitted well predicting the adsorption capacity of 427.11\xa0mg\xa0g−1. The BC became more selective in copper removal after the introduction of Fe0, and a higher removal rate of Cu(II) was observed in a short time compared to the other tested adsorbents. Therefore, zero-valent iron composited orchard waste-derived biochar as a green and cost-effective adsorbent can open new ways for the efficient removal of Cu(II) from aqueous solutions.