Fine Particle Adsorption Capacity of Volcanic Soil from Southern Kyushu, Japan

Abstract

“Akahoya” is a volcanic soil classified as a special soil deposited in Kyushu, Japan. Many of its properties are not yet clearly understood. We found that Akahoya had the potential to adsorb bacteria in cattle feces, which prompted us to investigate its material properties and perform experiments to comprehensively evaluate its adsorption performance for various fine particles such as acidic and basic dyes, NOx/SOx gas, and phosphoric acid ions, in addition to bacteria. Akahoya had a very high specific surface area owing to the large number of nanometer-sized pores in its structure; it exhibited a high adsorption capacity for both NO2 and SO2. Regarding the zeta potential of Akahoya, the point of zero charge was approximately pH 7.0. The surface potential had a significant effect on the adsorption of acidic and basic dyes. Akahoya had a very high cation exchange capacity when the sample surface was negatively charged and a high anion exchange capacity when the sample surface was positively charged. Akahoya also exhibited a relatively high adsorption capacity for phosphoric acid because of its high level of Al2O3, and the immersion liquid had a very high Al ion concentration. Finally, filtration tests were performed on Escherichia coli suspension using a column filled with Akahoya or another volcanic soil sample. The results confirmed that the Escherichia coli adhered on the Akahoya sample. The results of the Escherichia coli release test, after the filtration test, suggested that this adhesion to Akahoya could be phosphorus-mediated.

Nanostructured and Functional Nanomaterials for Energy Storage and Removal of Pollutants

“…The present Special Issue contains eight papers [5][6][7][8][9][10][11][12] devoted to the synthesis and application of nanostructured materials for water decontamination through adsorption, photocatalysis and filtration and the building of high energy density energy storage devices. The papers present different nanostructured materials such as Doped biomassactivated carbon materials, Titanate Perovskite-Based Nanocomposites, composites based on Graphene Oxide/TiO 2 , Nano-Clay, Three-Dimensional Na 3 V 2 (PO 4 ) 3 /Carbon Frameworks, and Nanostructured ZnO.…”

“…These nanomaterials have been applied in the decontamination of polluted synthetic waters, including the adsorption of dyes [6,7], the filtration of heavy metals [6], adsorption coupled with ultrafiltration to remove nitrite ions [8], and the removal of dyes and organic contaminants using photocatalysis [9,10] to the degradation of dyes and pharmaceuticals, along with heavy metal ion and radioactive ion extraction.…”