Optimization of lead adsorption from lead-acid battery recycling unit wastewater using H2SO4 modified activated carbon

During the recycling of exhausted lead-acid battery, large amount of wastewater is discharged, which contains the toxic Pb(II) ions in high concentration. In this study, the granular activated carbon after modification with sulfuric acid has been used to remove the Pb(II) ions from this wastewater. Adsorbents were characterized using Fourier Transform Infrared, Scanning Electron Microscope, and X-Ray Diffraction analyzer. Taguchi orthogonal L16 array (4^3) was used for batch adsorption study with four levels of three factors initial pH, adsorbent dose, and contact time. Optimum level of parameters was fourty + nd pH 4.5, time 240 min, and dose 0.05 g/50 mL using signal-to-noise ratio (larger-the-better response). Analysis of variance technique was used to signify the adsorption experiment model. The effect of parameters on uptake capacity of adsorbent has been evaluated. Maximum adsorbent capacity for Pb(II) uptake from wastewater of battery recycling unit was found 8.19 mg/g after modification with sulfuric acid. To further understand the mechanism of adsorption, isotherm and kinetic studies were carried out. Experimental data were well fitted with Langmuir isotherm model and pseudo-second-order kinetic model. The study suggested that H₂SO₄ modified granular activated carbon can be potentially used to remove Pb(II) from lead-acid battery recycle wastewater.