A synergistic integration of life cycle assessment and response surface methodology to optimize grape stalk waste-based biosorption for effective Cd(II) removal

Abstract

In order to remove Cd(II) ions from aqueous solutions, this research suggests an in-depth study on a laboratory scale for the efficient and sustainable removal of Cd(II) in aqueous solution using wine industry grape stalk waste. The maximum biosorption capacity that was achieved was 84.74 mg/g for the Langmuir isotherm model. The kinetic studies revealed that the biosorption data were better explained by a pseudo-second order model. By using the response surface method with desirability functions, the optimal variables were determined for three optimization scenarios. The first optimization scenario yielded the highest percentage of cadmium removal, reaching 87.75%. The goal of that scenario was intended to obtain the maximum percentage of cadmium removal while minimizing the cost of the process. In this scenario, the greatest environmental impact was on the marine aquatic ecotoxicity (2.685 kg 1.4 DB eq.) with a power consumption of 27.05 W. Furthermore, the values for the input variables were an initial cadmium concentration of 0.6 mg/l, pH of 7.5, stirring time of 10 min, stirring speed of 100 rpm, a process temperature of 15 °C, and a dose of grape stalk of 0.50 g. The experimental and predicted findings agree. This suggests that grape stalk waste has potential applications as a biosorbent for the removal of Cd(II) ions from aqueous solution.