INVESTIGADORES
CRISTOBAL Adrian Alberto
congresos y reuniones científicas
Título:
PHYSICOCHEMICAL AND ENVIRONMENTAL CHARACTERIZATION OF TWO BIOMASS WASTES
Autor/es:
NANCY QUARANTA ; MARTA CALIGARIS; GISELA PELOZO; ANDREA CESARI ; ADRIÁN CRISTÓBAL
Reunión:
Simposio; ISGC 3rd international symposium on green chemistry; 2015
Resumen:
Organic material originated from a natural or induced process that can be used as an energy source is called biomass residue. Within the wastes obtained from biomass process, two types of residues can be mentioned: those who remain as residual materials from the own productive process, such as olive pits, peanut shells, corncobs; and the ashes obtained when these residues are effectively used as fuel to produce energy. In this work, peanut shells and waste from the brewery are studied in order to assess their environmental suitability for use as fill or soil improvers. Various characterization techniques such as energy dispersive analysis of X-rays, differential and gravimetric thermal analyses, pH, conductivity and ecotoxicity among others, are used. Ecotoxicity testing is carried out by adapting the IRAM 29114: 2008 standard, using ryegrass species seeds and dilutions of 25%, 50% and 100% of the eluate and then measuring the percentage inhibition of the radicle elongation. Figure 1 shows photographs of these residual materials taken with a magnifier. Chemical analysis shows that both residues are composed almost entirely of C and O; in the case of beer residue 60.6% C and peanut shell 54.0% C. Also, in much smaller quantities Mg, Si, S, K and Ca, were found. It is important to know pH and conductivity parameters in order to consider modification of soil characteristics on which the residues are to be deposited. For the studied residues the values of these parameters, conductivity and pH, are 1.906 mS and 5.15 for peanut shells and 1.867 mS and 4.5 for brewery residue. Both residues may be used as acidifying of soils. The combination of chemical analysis with ecotoxicity testing, as an integrated strategy to characterize a sample, has the advantage of providing more complete information about the possible toxic effects of it. Unlike traditional seed germination test, evaluation of the effect on the seedling radicle elongation allows determining the toxic effect of soluble compounds present in very low concentration levels in the waste sample. The results of this test show that both residues have a negative influence on the growth of radicles. This effect is more pronounced for beer residue. Thermal analysis of residues from beer fabrication is shown in Figure 2. In the range 20-250C a small loss in TGA curve is observed. It is assigned to the H2O loss and the release of light adsorbed gases. Exothermic peaks in DTA curve are observed between 250-600C, corresponding to degradation and decomposition reactions. At 317C the thermal fragmentation of glucosidic bonds of cellulose and hemicellulose takes place, generating volatiles with high content of oxygen, leaving a carbonaceous residue. Above 400C char are degraded releasing gases and aromatics compounds [1,2]. XRD patterns of these biomass residues show the profile of noncrystalline organic samples, and a small ridge characteristic of silica at low angles is observed. FIG1 LEGEND Photographs of residual materials (a) brewery waste (b) peanut shells. Magnification x50. FIG2 LEGEND DTA-TGA of brewery waste KEYWORDS biomass waste | peanut shells | brewery waste REFERENCES [1] F. Collard, J. Blin. Renewable and Sustainable Energy Reviews, 2014, 38, 594-608. [2] K.Tekin, S. Karagoz, S. Bektas. Renewable and Sustainable Energy Reviews, 2014, 40, 673-687.