Pinus radiata forest residue: A bio-adsorbent of choice for Cr (VI) removal from aqueous solution

Abstract

Hexavalent chromium (Cr(VI)) is a lethally harmful heavy metal that endangers human health and biodiversity worldwide. Conventional Cr(VI) removal procedures are frequently energy-consuming and also emit hazardous byproducts. The use of NaOH-activated Pinus radiata forest residue (PRFR) as a sustainable and adaptable adsorbent for the effective removal of Cr(VI) from aqueous solutions is demonstrated in this work. To validate the adsorption and adsorption mechanism, PRFR was characterized using FTIR (Fourier transform infrared spectroscopy), SEM (Scanning electron microscopy), and XRD (X-ray diffraction) methods. Batch experiment techniques were adopted to optimize the influences of initial concentration, pH, adsorbent dose, temperature, and contact duration for Cr(VI) adsorption, all of which are critical for use on an industrial or commercial scale. After 45 min of contact time, PRFR revealed a high adsorption capacity of 13.947 mg/g with a removal effectiveness of 99.12 % for Cr(VI). The adsorbent was reusable for more than three cycles. PRFR is a nature-friendly adsorbent that can be used for a variety of purposes, including wastewater treatment, industrial effluent remediation, and environmental restoration, because it is inexpensive and easily accessible.