Role of nano-magnetized Citrus X sinensis (orange) peels for decontamination of pendimethalin from aqueous resources: a comparative study of untreated and carbonaceous orange peels with nano-magnetized peels

Biosorption is a low-cost, environment friendly wastewater treatment method that involves a simple procedure for the removal of pesticides and their residues from wastewater. In the present investigation, untreated Citrus X sinensis peels (U-CXSP), activated carbon Citrus X sinensis peels (AC-CXSP) and nano-magnetized Citrus X sinensis peels (NM-CXSP) adsorbents were applied for the uptake of pendimethalin (PDM) from aqueous resources. The laboratory-prepared adsorbents were characterized using SEM, EDX, FTIR, VSM and XRD. Biosorption studies were carried out by varying different parameters, i.e., adsorbents dosage (0.1–0.5 g), time of contact (10–70 min), initial concentration of PDM (5–200 ppm), pH and temperature. The results showed that the removal efficiency of U-CXSP was increased from 97 to 114 mg/g for AC-CXSP adsorbent and increased from 97 to 111 mg/g for NM-CXSP adsorbent. Kinetics data obtained from this study well fitted with pseudo-second-order kinetic model. Adsorption isotherms were studied and the adsorption data well fitted with Langmuir and Freundlich models. Order of the adsorption efficiency is observed as follows: AC-CXSP > NM-CXSP > U-CXSP.