Integrated phytoremediation of lead and cadmium-contaminated soils using Helianthus annuus: A pathway to green remediation

Ushna Saleem and Wasiq Ikram

Abstract

Phytoremediation is an eco-friendly and cost-effective approach that utilizes plants to remediate heavy metal contamination in urban and rural environments. A greenhouse study was conducted to evaluate the ability of sunflowers (Helianthus annuus L.) to absorb heavy metals such as lead (Pb) and cadmium (Cd) from contaminated soils. The soil was treated with varying concentrations of Pb (100 and 150 mg/kg) and Cd (20 and 30 mg/kg), as well as combinations of Pb and Cd (10+50 and 15+75 mg/kg). Fertilizers including urea, di-ammonium phosphate (DAP), and potassium sulfate (SOP) were applied to the treatments. The collected soil was sterilized using 10% formalin, and its physical properties—such as water content, organic matter, pH, and particle size—were assessed following ASTM standards. Results indicated that the sunflower's ability to remediate individual metals was more effective than for combined metal treatments. The efficiency of phytoremediation increased with higher concentrations of Pb and Cd. Statistical analysis using Tukey's HSD test further highlighted sunflower's significant potential as a phytoremediator, alongside its role in food and energy production.