NO2- and NO3- leaching and solubilization of Al in variable charge soils treated with sewage sludge

Autor(es)

Borba, Ricardo Perobelli ^[1] ; de Camargo, Otavio Antonio ^[2] ; Kira, Carmen Silvia ^[3] ; Coscione, Aline Renee ^[2]

Afiliação do(s) autor(es)

^[1] Univ Estadual Campinas, Inst Geociencias, BR-13083870 Campinas, SP - Brazil

^[2] Inst Agron SP, Ctr Solos & Recursos Ambientais, BR-13012970 Campinas, SP - Brazil

^[3] Adolfo Lutz Inst, Ctr Alimentos, BR-01246902 Sao Paulo, SP - Brazil

• Tipo de documento: Artigo Científico
• Fonte: ENVIRONMENTAL EARTH SCIENCES; v. 74, n. 6, p. 4625-4638, SEP 2015.
• Citações Web of Science: 2

Resumo

The use of sewage sludge (SS) for agricultural purposes provides macronutrients and micronutrients and increases the soil organic matter. This study was conducted after 5 years of agricultural sludge application to a variable charge soil (clay loam-textured dark red dystroferric oxisol) in an experimental field at the Brazilian Federal Agriculture Research Institute in JaguariA(0)na, So Paulo. The mineralization of SS organic matter forms sulfate (SO4 (2-)) and ammonium (NH4 (+)) or ammonia (NH3). Subsequently, nitrification of NH4 (+) or NH3 occurs, resulting in the formation of nitrite (NO2 (-)) and NO3 (-) which release H+ and increases the redox potential of the solution. In studied area, the SS organic matter decomposition favored the anion exclusion, which led to SO4 (2-), NO2 (-) and NO3 (-) leaching along the profile. At 2 m, the soil solution showed pH and Eh values of 4.2 and 600 mV, respectively. In addition, the highest soil NO2 (-) (27 mg/L), NO3 (-) (1220 mg/L) and Al (20 mg/L) concentrations were observed at 2 m. The low pH and high Eh at 2 m potentially resulted from the oxidation of leached NO2 (-). Furthermore, the H+ released in solution due to nitrification was partially consumed during the solubilization of soil Al compounds, such as kaolinite and amorphous Al oxide. Geochemical modeling (GM) indicated that Al3+ in solution results from the solubilization of kaolinite and amorphous Al oxide. GM also highlights the importance of soil oxide protonation in buffering the soil solution acidity and in controlling the solubility of Al compounds and free Al in solution. (AU)

• Processo FAPESP: 02/12671-2 - Mobilidade de metais pesados (Cd, Cu, Ni,Pb e Zn) na zona não saturada, e possível contaminação do aquífero livre, decorrente da aplicação agrícola do lodo de esgoto em latossolo ácido
• Beneficiário: Otávio Antonio de Camargo
• Modalidade de apoio: Auxílio à Pesquisa - Regular
• Processo FAPESP: 02/09667-3 - Mobilidade de metais pesados (cd, cu, ni, pb, zn) na zona nao saturada, e possivel contaminacao do aquifero livre, decorrente da aplicacao agricola do lodo de esgoto em latossolo acido.
• Beneficiário: Ricardo Perobelli Borba
• Modalidade de apoio: Bolsas no Brasil - Pós-Doutorado
• Processo FAPESP: 03/10949-6 - Mobilidade de metais pesados (Cd, Cu, Ni, Pb e Zn) na zona não saturada, e possível contaminação do aquífero livre, decorrente da aplicação agrícola do lodo de esgoto em latossolo ácido
• Beneficiário: Ricardo Perobelli Borba
• Modalidade de apoio: Auxílio à Pesquisa - Programa Primeiros Projetos