Otilio Arturo Acevedo Sandoval

Zeta potential and electrophoretic mobility for the recovery of a saline soil with organic amendments

The accumulation of salts in the soil profile produces conditions that affect the growth of crops. The effects of these conditions on crops and the intensity of these effects depend on the quantity and type of salts that predominate and are also influenced by soil characteristics and climate, among other aspects. The salinization of agricultural soils is a serious problem facing agriculture today. The use of organic amendments has increased in recent years, acting on the texture of the soil, correcting compaction or granularity problems, and influencing chemical and/or biological reactions. The objectives of this work were to analyze the use of compost and vermicompost using different analysis techniques to determine the influence of conditions on the remediation of a saline soil. In saturation extracts of soil, compost, and vermicompost, a Zeta potential value 2.34–2.44 times more negative (more-stable colloids) than that in the soil colloids was observed in the amendments. The values of electrophoretic mobility were more negative in the organic amendments compared with the soil. This is the first time that these parameters have been reported for these purposes and for a saline soil. In this study, the soil has low organic matter content (1.65%), so these amendments are expected to improve soil quality and texture, achieving the recovery of saline soils.

Physico-Chemical Characterization of Agricultural Residues as Precursors for Activated Carbon Preparation

Flores, R.A.C., F.P. García, E.M.O. Sánchez, A.M.B. Miró and O.A.A. Sandoval, 2018. Physico-chemical characterization of agricultural residues as precursors for activated carbon preparation. Bulg. J. Agric. Sci., 24 (3): 427–436 Biomass is a promising alternative and renewable energy source that can be transformed into other value-added products such as activated carbon. In this research, barley husk, corn cob and Agave salmiana leaves were characterized to determine their chemical composition and morphology to evaluate their potentiality as precursors of activated carbons. Based on the main composition results obtained, the biomass samples have suitable chemical and physical characteristics to be considered as good precursors of activated carbons, such as carbon contents greater than 40%, ash content less than 10%, moisture content less than 30%, high volatile contents with values from 75 to 80% and a porous and fi brous morphology. The results indicate that the main compositions in the biomass were cellulose and lignin. The cellulose content was more than lignin (15-26%) for the residues selected. Specifi cally, α-cellulose contents with values from 52% to 79%, β-cellulose contents of 13-44%, γ-cellulose contents less than 11%, and holocellulose contents of 82-83% were determined. The thermal decomposition for the biomass samples proceeded with fi ve stages attributed to the evaporation of some volatile compounds (70-150°C), to the degradation of hemicellulose (180-230°C), to the cellulose volatilization (250-350°C), to the lignin decomposition (380-550°C), and to the degradation of complex polymers and inorganic salts, respectively. The stage corresponding to the cellulose decomposition showed rapid mass decreased in the three residues. This results show that the cellulose and lignin content is another important parameter to evaluate the pyrolysis characteristics of a good precursor of activated carbon.