Alternative technique using Biochars to improve the quality of soil contaminated with zinc

• Grant number: 16/14102-8
• Support Opportunities: Scholarships in Brazil - Master
• Effective date (Start): January 01, 2017
• Effective date (End): May 31, 2018
• Field of knowledge: Agronomical Sciences - Agronomy - Soil Science
• Acordo de Cooperação: Coordination of Improvement of Higher Education Personnel (CAPES)
• Principal Investigator: Cleide Aparecida de Abreu
• Grantee: Lindiamara Sertoli
• Host Institution: Instituto Agronômico (IAC). Agência Paulista de Tecnologia dos Agronegócios (APTA). Secretaria de Agricultura e Abastecimento (São Paulo - Estado). Campinas , SP, Brazil

Abstract

Recently, soils treated with biochars have shown positive results on soil chemical, physical and biological characteristics. However, the extent of biochar contribution to soil recovery depends on the biomass origin, the biomass burning conditions and the soil characteristics. Therefore, it is necessary to have biochar as an easily available, ecologically correct and low-cost product to be considered a feasible technique to restore or remediate areas contaminated with heavy metals. For that, it is important to choose the adequate biomass, which does not have any efficient final destine or any aggregated agronomic value, but is largely produced, such as the waste of coffee grounds and the fine coal. Therefore, the present research proposal main objective is to evaluate the efficiency of biochars from industrial waste originated from the soluble coffee production (coffee grounds), from coffee parchment removal from dry coffee beans, and from fine coals, on the recovery of soils contaminated with heavy metals, as an alternative technique to improve soil quality. Biomass originated from coffee industry will be submitted to pyrolysis at 700oC, and following, to chemical, physical and image analysis (MEV). In the first experiment, each biochar sample will be analyzed to determine the maximum capacity of zinc (Zn) adsorption and desorption (the major contaminant). The treatments will consist of soil samples (0-20 cm depth) from Zn-rich area (absolute control, without pH adjustment and without biochar addition); soil plus 5% (m/m) of biochar from coffee grounds; soil plus 5% (m/m) of biochar from coffee parchment; soil plus 5% (m/m) of fine coal. Nevertheless, if pH increase occurs due to alkalinity of the biochar from coffee biomass, two more treatments will be added to the experiment, without biochar and with pH adjustment. The treated soil samples will be incubated for 90 days. In different time periods, samples will be analyzed for chemical determinations (pH, organic matter (OM), P, K, Ca, Mg, CEC, Al, Fe, Mn, Cu, Zn, Cd, Ni, and Pb); microbiological analysis (microbial biomass carbon, basal respiration, metabolic quotient, microbial quotient, dehydrogenase activity, ²-glycosidase activity, protease); and physical analysis (particle size classification and water retention curve). Furthermore, the index of soil quality (ISQ). (AU)