title: Carbon sequestration in soil by in situ catalyzed photo-oxidative polymerization of soil organic matter.
abstract: Here we describe an innovative mechanism for carbon sequestration in soil by in situ photopolymerization of soil organic matter under biomimetic catalysis. Three different Mediterranean soils were added with a synthetic water-soluble iron-porphyrin, irradiated by solar light, and subjected first to 5 days incubation and, then, 15, and 30 wetting and drying (w/d) cycles. The in situ catalyst-assisted photopolymerization of soil organic carbon (SOC) increased water stability of soil aggregates both after 5 days incubation and 15 w/d cycles, but not after 30 w/d cycles. Particle-size distribution of all treated soils confirmed the induced soil physical improvement, by showing a concomitant lower yield of the clay-sized fraction and larger yields of either coarse sand- or fine sand-size fractions, depending on soil texture, though only after 5 days incubation. The gain in soil physical quality was reflected by the shift of OC content from small to large soil aggregates, thereby suggesting that photopolymerization stabilized OC by both chemical and physical processes. A further evidence of the carbon sequestration capacity of the photocatalytic treatment was provided by the significant reduction of CO(2) respired by all soils after both incubation and w/d cycles. Our findings suggest that "green" catalytic technologies may potentially be the bases for future practices to increase soil carbon stabilization and mitigate CO(2) emissions from arable soils.
authors.affiliation: Dipartimento di Scienze del Suolo, della Pianta, dell'Ambiente e delle Produzioni Animali, Università di Napoli Federico II, Portici, Italy. alessandro.piccolo@unina.it
authors.forename: Alessandro
authors.initials: A
authors.lastname: Piccolo
authors.forename: Riccardo
authors.initials: R
authors.lastname: Spaccini
authors.forename: Antonio
authors.initials: A
authors.lastname: Nebbioso
authors.forename: Pierluigi
authors.initials: P
authors.lastname: Mazzei
mesh_terms: D057965:Carbon Sequestration / Q000528:radiation effects*; D002384:Catalysis / Q000528:radiation effects; D007558:Italy; D008027:Light; D009930:Organic Chemicals / Q000737:chemistry*; D010084:Oxidation-Reduction / Q000528:radiation effects; D010316:Particle Size; D058105:Polymerization / Q000528:radiation effects*; D012987:Soil / Q000737:chemistry*; D014867:Water / Q000737:chemistry
chemical_list: D009930:Organic Chemicals; D012987:Soil; D014867:Water