ABSTRACT
Vineyard pruning waste (VP) can be converted into a useful char using pyrolysis as part of a valorization strategy. This study analyzed the effect of temperature (300 and 600 °C) and residence time (1 and 3 h) on an ample number of properties of VP derived biochars, including potential negative environmental impacts. The results showed a clear influence of temperature on biochar's properties and a weaker effect of residence time. Increasing temperature raised soil pH, electrical conductivity (EC), ash and C contents, aromaticity, specific surface area, solid density, mesoporosity and partial graphitization. However, higher pyrolysis temperature reduced O/C and N/C ratios, total N, P and Mg, and polycyclic aromatic hydrocarbons (PAHs). Particularly, the concentration of water extractable organic carbon (WEOC) decreased dramatically with pyrolysis temperature. Moreover, the WEOC fraction of biochars pyrolyzed at 300 °C exhibited a larger aromaticity than those pyrolyzed at 600 °C. Prolonged residence time increased ash content and fixed carbon (FC) and decreased H/C and O/C ratios; however, most frequently this parameter affected biochar properties following opposite trends for the two pyrolysis temperatures. Hydrophysical properties were adequate to consider VP derived biochars as growing media component. PAH concentration was much lower than thresholds following international standards. The germination index increased with temperature and decreased with residence time, so that phytotoxicity was observed in VP and in biochars pyrolyzed for 3 h. Our research demonstrates that, besides temperature, residence time can be useful to modulate the properties of biochars and that prolonged time effect is temperature-dependent.
ABSTRACT
This work quantified ecosystem services (ES) and the geographic gross product (GGP) at municipal level in the Metropolitan Region of Buenos Aires (MRBA), Argentina. The ES offer and GGP were evaluated for each land use (extensive agriculture EA, intensive agriculture IA, urban and periurban agriculture UPA, green areas GA, urban use URB), expressed as a percentage (%), at the municipality level. Municipalities with a greater URB percentage (<70) presented an elevated ES offer from GA. In periurban municipalities EA contributed to ES offer more than other vegetated land uses (IA, GA, and UPA). Urban municipalities presented 20% more GGP than periurban municipalities. The GGP was negatively associated with total ES offer (-0.34) and ES offer from EA (-0.46). The identification and quantification of ES and GGP is relevant for achieving an adequate landscape planning and a sustainable environmental and economic use of urban systems.
