"EMU: Acquisition of an ionic chromatograph for speciation of soil solutions of agronomic and environmental interest, involving inorganic cations and anions and organic acids of low molar mass"

• Grant number: 23/17029-3
• Support Opportunities: Research Infrastructure Program - Small Medium Sized
• Start date: September 01, 2024
• End date: August 31, 2027
• Field of knowledge: Agronomical Sciences - Agronomy - Soil Science
• Principal Investigator: Luís Reynaldo Ferracciú Alleoni
• Grantee: Luís Reynaldo Ferracciú Alleoni
• Host Institution: Escola Superior de Agricultura Luiz de Queiroz (ESALQ). Universidade de São Paulo (USP). Piracicaba , SP, Brazil
• Associated researchers: José Alexandre Melo Demattê ; Tiago Tezotto

Abstract

The ionic chromatograph will be used to obtain the species of inorganic cations and anions and low molar mass organic acids in the soil solution from an agronomic point of view, involving the dynamics of carbon and other mineral nutrients in conservationist agricultural production systems, in addition to the environmental perspective, involving the behavior of potentially toxic elements in contaminated areas. The chemical species of the elements will be determined by ionic chromatography and will provide important insights into the state of that environment, which, when associated with simpler measurements, such as oxidation-reduction potential and pH, support the prediction of the behavior of potentially toxic elements, such as immobilization by precipitation or by formation of oxides, leaching potential or bioavailability.A pioneering application will be the determination of oxalic acid content as an indicator of the biological activity of fungi that has the potential to remove heavy metals from environmental waters through intracellular bioaccumulation and extracellular adsorption. The possibility of determining the concentration of low molar mass organic acids is also related to an innovative project with the potential for great scientific impact, CCarbon, one of FAPESP's current Diffusion and Information Research Centers (CEPID), of which the proponent is the Director of Dissemination and one of the main researchers. The quantification of anions in solution will be the chromatograph's greatest contribution to the project linked to the sequestration of C in the soil and greenhouse gas emissions to mitigate climate change, which will improve scientific understanding of the C cycle (especially organic acids) in agricultural systems and will provide relevant information on C sequestration in the tropics. When evaluating the impact of variations in ambient temperature on chemical and biological attributes of a soil contaminated by zinc and cadmium and remediated with biochar, it is expected that the ion concentration results determined by the ionic chromatograph, which will be used for geochemical modeling, will allow obtain Cd and Zn species formed in solution and correlate them with their bio/geoavailability. In the study of phosphorus dynamics in soils amended with alternative sources of phosphate fertilizers, the use of the device will make it possible to obtain P species formed in soils amended with conventional mineral fertilizers, as well as alternative fertilizers. In turn, in the project that studies thiol-modified nanobiochar in controlling the biogeochemistry of Hg in soil in the Amazon region contaminated by mining activities, changes in the redox condition are included, in which sulfur can be in an oxidized or reduced form, which can interfere with the toxicity and mobility of mercury. Furthermore, the quantification of the content of low molar mass organic acids can be indicative of biochar nanoparticle degradation under anoxic conditions.In another project, the results from the chromatograph will be used to validate the use of remote sensing and machine learning algorithms with cloud processing to assess soil quality. The contents of the elements and their respective species obtained by chemical extraction and correct analytical determination on the chromatograph will allow the validation of integrated methodologies via geotechnologies, geoprocessing, pedotransfer and soil functions that allow mapping, with high spatial resolution, the quality of soils throughout Brazilian territory. (AU)