The study aimed to examine the use of nitric acid modified granular activated carbon to treat the wastewater of lead-acid battery recycling unit for lead removal. The adsorbent was characterized using FTIR, SEM, and XRD analysis. Surface functional groups, surface morphology and crystallinity has been changed due to modification. The batch adsorption study was conducted to evaluate the effects of adsorbent dose, initial pH, and contact time on adsorption performance for lead removal. Experiments were performed according to Taguchi design of experiment method and factors were optimized based on SNR analysis to maximize the response. The ideal factor values were found as pH 6, adsorbent dose of 0. 05 g, and time of 240 minutes for the adsorption of lead onto adsorbent with the adsorbent uptake capacity of 9. 93 mg\, g^-1. From ANOVA analysis pH was found most significant factor with F-value of 28. 07. Isotherm and kinetic studies were also carried out to understand the mechanism of adsorption. Adsorption was found to follow the Langmuir isotherm and second order kinetic model.
Meshram et al. (2026) studied this question.