Pomegranate‐Peel Derived Carbon Quantum Dots Iron Oxide (PPCQD‐Fe ₃ O ₄ ) Nanocomposite Adsorbent for Arsenic and Nickel Removal from Soil

ABSTRACT This study investigated the effectiveness of PPCQD‐Fe 3 O 4 nanocomposite to extract arsenic (III) and nickel (II) from soil. The optimal conditions for batch treatment were determined: an initial concentration of 20 ppm for both metals, pH 8 for arsenic and pH 4 for nickel, a contact time of 60 min for arsenic and 120 min for nickel, and a soil‐to‐PPCQD Fe3O4‐nanofluid ratio of 1:20. The selective sequential extraction technique was used to evaluate the efficiency of arsenic and nickel removal from different soil fractions using PPCQD‐Fe 3 O 4 nanofluid. The removal rates were: 94.6% arsenic and 93.8% nickel from carbonates, 96% arsenic and 95.5% nickel from oxides and hydroxides, 82.4% arsenic and 84.4% nickel from the residual fraction, 92% arsenic and 94% nickel from organic matter, and 100% removal from the exchangeable fraction for both metals. These results indicate that the PPCQD‐Fe 3 O 4 nanocomposite is highly effective in removing arsenic and nickel from soil.