The joint use of LCA and emergy evaluation for the analysis of two Italian wine farms

The aim of this paper is to evaluate two agroindustrial productive processes in their entirety (one organic and one semi-industrial), focusing on the comparison of impacts derived from the inputs and outputs of the system (life cycle assessment, LCA), integrated with a physical evaluation of the resources and natural services, on a common basis (emergy). Methods based on the joint use of LCA and emergy evaluation are useful, as they measure the contribution of environmental services and products to the productive process thus focusing primarily on the environmental impact of emissions and non-renewable energy inputs. The complementarity of the methods used in this paper contributes important elements and information useful for the comprehension of the organization of agriculture within Siena's territory. The results show important elements and useful information: (1) for the comprehension of the two agroecosystems' organization; (2) for the use of the energy flows that determine their development. Moreover, the combined use of emergy and LCA gives a comparative thermodynamic performance evaluation between organic and semi-industrial farming.     

Effect of aging on catalytic properties in mechanochemical degradation of pentachlorophenol by birnessite

Mechanochemistry, a technique concerning with milling contaminated samples for prolonged times, induces massive degradation of pollutants by grinding them in ball mills with different soil components or additives. In the present study, laboratory experiments were conducted to evaluate the effect of aging on the mechanochemical efficiency of the Mn-oxide birnessite in degrading pentachlorophenol (PCP). A comparative study on an aged birnessite (KBiA), used after 3 years from synthesis, and a fresh birnessite (KBiF), employed immediately after synthesis, was carried out. The differences between the two birnessites, evidenced by spectroscopic and diffractometric techniques, are mainly relative to reduction of the Mn(IV) centered at the MnO₆ octahedra layers from the birnessite structure, which represent the most reactive sites for PCP degradation. The long term air drying at room temperature, by favouring reduction of Mn(IV) to Mn(III), produces an inorganic substrate that offers paucity of the less reactive sites for PCP degradation, thus reducing the oxidative potential of the KBiA. Accordingly, the more reactive fresh birnessite was employed in the experiment with a polluted soil. Adding a small amount of KBiF to soil only induces a light increase in PCP removal, probably due to the mechanically induced PCP adsorption and transformation onto clay minerals present in the soil. Besides, adding a higher dose of birnessite causes a stronger degradation of PCP.     

Mechanochemical removal of organo-chlorinated compounds by inorganic components of soil

The purpose of this work is to evaluate the catalytic efficiency of two metal oxides, ferrihydrite and birnessite and of a ferruginous smectite, towards organic molecules such as 4-chloroaniline (4-CA), pentachlorophenol (PCP), and five polychlorinated biphenyls (PCBs) characterised by different number and position of chlorine atoms. Mechanochemical dry contacts with light grinding between catalytic surfaces and pollutants have been carried out.

The efficiency of the mechanochemical removal was compared with batch experiments for the soluble compounds (PCP and 4-CA). The removal of 4-CA and PCP by the mechanochemical procedure resulted more effective than by batch contact in the presence of birnessite and ferrihydrite, particularly at higher pH (100% removal of 4-CA by birnessite in 30 min at pH 8.6 after the mechanochemical contact compared to 20% removal using the batch interaction at the same pH).

The mechanochemical contact of PCBs and birnessite produced a removal of pollutant that was a function of the number of chlorine atoms (complete removal of 2,2^′-dichlorobiphenyl in 10 days and a removal of 30% and 20% of 2^′,3,4-trichlorobiphenyl and 3,3^′,4,4^′-tetrachlorobiphenyl, respectively in 90 days) and of the position of chlorine atoms about the biphenyl rings (100% of 2,2^′-dichlorobiphenyl in 10 days, 84% of 3,3^′-dichlorobiphenyl in 15 days and 40% of 4,4^′-dichlorobiphenyl in 27 days).