Carbon-mineral adsorbents with a diatomaceous earth/perlite matrix modified by carbon deposits

Carbon-mineral adsorbents (CMA) were prepared using complex diatomaceous earth/perlite adsorbent spent in purification of apple juice and carbonized with addition of starch or glucose to enhance the content of carbon deposits and to develop the porosity of the CMA. The specific surface area of the carbon deposits was 500–640 m2/g at the pore volume Vp = 0.28–0.35 cm3/g depending on the type of an additive and the amounts of grafted carbon. Carbon deposits in CMA represent nanoparticles (nanodeposits) totally covering a surface of the mineral matrix. Thermal stability of these nanoparticles is lower than that of larger microparticles of activated carbon (AC) or carbon black. Contribution of aromatic structures with C atoms with the sp2 hybridization is larger in CMA than AC but smaller than in graphitized carbon black.

Carbon-mineral adsorbents with a diatomaceous earth/perlite matrix spent in fruit juice purification and modified by carbonized residual organics with added starch or glucose.Figure optionsDownload as PowerPoint slideHighlights
► Carbon-mineral adsorbents were prepared using waste diatomaceous earth/perlite adsorbent.
► Porosity is a non-linear function of carbon content.
► Carbon nanodeposits totally cover a surface of the mineral matrix.
► Thermal stability of carbon nanodeposits is lower than that of activated carbon or carbon black.