Environmental applications of carbon-based materials: a review

Environmental pollution is a major issue, yet actual remediation techniques are limited. Carbon-based materials are increasingly used to treat air and water. Here we review the applications of carbon nanomaterials made of biochar, activated carbon, carbon nanotubes and graphene for the adsorption of toxic gases, the removal of pollutants from ecosystems, and the improvement of anaerobic digestion. Carbon materials have been found efficient in removing nitric oxide, hydrogen sulfide, heavy metals, dyes, pharmaceutical compounds and other pollutants from the environment, with adsorption efficiencies reaching 80% and degradation efficiencies up to 99%. Biochar addition induces a 60% improvement in biogas production. Similarly, in composting, up to 60% less ammonia emissions were observed when biochar was added. Biomass-based carbon materials appear economical, sustainable and eco-friendly.