Carbon Xerogels for Effluent Treatment
Athulya Pillai, Balasubramanian Kandasubramanian
Abstract
The adsorption process of carbonized xerogels in the form of porous microspheres or monoliths was found to be reversible. This indicated that the xerogels could be reusable, making the process of effluent treatment in eradicating metal ions and reactive dyes cost-effective and propitious. With the outburst of several kinds of water-borne epidemics, concern for effluent treatment has become a more significant factor in the design of new advanced treatment technologies. Consequently, some higher levels of effluent treatments assisted with more advanced materials were able to remove all pollutants from sewage; in contrast, their exorbitant mechanisms created hurdles in a long term perspective. Carbon and its diverse types, such as nanotubes, activated forms, and graphene oxide-incorporated carbon gels, were all studied, and their adsorption of different metal ions, the catalytic reduction, and adsorption of reactive dyes were mentioned concisely. Carbon xerogels possess very low densities (0.04–1.3) g/cm3, micromesoporous size (<50 nm), and large surface areas (600–800) m2/g, and due to their most straightforward route of preparation and high microporous fractions, about 80% during carbonization, they are more preferred over other gels. This review paper discusses the synthesis of xerogels, carbonization processes, various carbon incorporated xerogels, appropriate adsorption isotherms, and the kinetic models they follow, and their efficacies in effluent treatment.