Eco-efficient cadmium(II) removal from water using alcohol distillate waste: A study of life cycle assessment

This study investigates the use of exhausted grape pomace, a byproduct of alcohol distillation, as a biosorbent for use in removing cadmium(II) from wastewater, in line with principles of a circular economy. Cadmium in water presents substantial environmental and health risks. Conventional treatment methods are often costly and environmentally damaging. This research proposes the use of agro-industrial waste as a sustainable and economical alternative. The biosorption process was optimized with Box-Behnken Design and Response Surface Methodology an adjusting factor such as the cadmium concentration, biosorbent dosage, solution pH, and stirring time. The findings reveal that cadmium(II) removal improves with increased stirring time, reaching a 99 % removal rate at 134 min. Optimal conditions include a biosorbent dosage of 2.4 g, pH 4.7, and initial cadmium concentration of 55 mg/L. The biosorption process also increased the solution’s pH, ensuring compliance with wastewater discharge regulations. Two optimization scenarios were evaluated. One achieved a 99.99 % removal efficiency for maximum cadmium reduction, The second focused on cost-effectiveness and environmental impact, attaining 77.35 % removal. This scenario highlights reduced the environmental impact, thereby supporting the role of exhausted grape pomace as a viable and eco-friendly option for wastewater treatment. Life cycle analysis, using CML-IA mid-point and ReCiPe end-point indicators, further underscores the sustainability of this approach, affirming the potential of grape pomace to contribute to circular, resource-efficient wastewater management.