RESPONSE SURFACE APPROACH FOR RECOVERY AND OPTIMIZATION OF COPPER (II) FROM POLLUED SOIL

Copper (II) extraction from polluted soil is crucial for environmental remediation. This study employed the Response Surface Method (RSM) to optimize the recovery of Copper (II) from contaminated soil. The effects of pH, stirring rate and ratio of solid to liquid and concentration of sulphuric acid on Copper (II) recovery from the contaminated soil were investigated. A quadratic model was developed to predict the recovery efficiency, and the optimal conditions were identified. Results showed that the maximum Copper (II) recovery of 98% was achieved, and it was found that the ideal values for the solid-to-liquid ratio, pH, sulphuric acid concentration, and stirring speed were 6. 5 g/100 mL, 300 rpm, and 0.25 mol/L, respectively. The elemental analysis by XRF showed that the contaminated soil is composed mainly of 10.5% Al2O3, 54.2 SiO2, 1.93 P2O5, 2.90 CaO, 2.14 TiO2, 23.5 Fe2O3, 0.26 ZrO2 and 3.11%CuO. Moreover, FTIR revealed the presence of Si-O-(Si) and Si-O-(Al) vibrations. The CCD model accurately predicted the recovery efficiency, with an R² value of 0.98. This study demonstrates the effectiveness of Centrale composite design in optimizing Copper (II) recovery from contaminated soil, providing a valuable approach for soil remediation and sustainable management. According to the results of these experiments, the leaching rate rose as the pH, stirring speed, acid concentration, and solid-to-liquid ratio decreased.