Technion-Israel Institute of Technology,
Keywords: activated carbon, life cycle assessment, central composite design, response surface methodology, selenite, adsorption
Summary:With the advances in material science, hybrid nanomaterials with unique structural and thermal characteristics have been developed. Among them, hybrids based on powdered activated carbon (AC) in combination with iron nanoparticles attract particular attention. Due to the structure and morphology, charge and energy transfer processes of AC lead to synergistic effects that allow the use of less material with higher productivity for water applications. In addition, the environmental advantages over prepared lignocellulose-based carbon, particularly in terms of acidification potential, non-renewable energy demand, and carbon footprint were evaluated using ISO 14040 series on LCA. The entry-level into the environment, sensitivity, major impact categories (carcinogens, respiration organics, respiration inorganics, climate change, radiation, the ozone layer, ecotoxicity, acidification, land use, minerals, and fossil fuels), availability of decision support variables were predicted by quantifying environmental interactions over the stages of the life cycle of AC manufacturing chain including disposal. After clarifying these issues, the iron nanoparticles were stacked up onto activated carbon to settle the composite. An indispensable role of the composite with high stability was tested for the complete removal of Se(IV) from wastewater at various influencing conditions. A four-factorial central composite design was anticipated, broke down through ANOVA for testing adsorption with optimum operational conditions. Adsorption isotherm study for the present system produces a 34.77 mg/g binding capacity of 2.75 g/L nanocomposites to Se(IV) ions. The present system was exothermic, unconstrained, and obeys both intra-particle and shrinking core diffusion models.