Accessing biochar's porosity using a new low field NMR approach and its impacts on the retention of highly mobile herbicides

Autor(es)

de Pierri, Leticia ^[1] ; Novotny, Etelvino Henrique ^[2] ; Pellegrino Cerri, Carlos Eduardo ^[1] ; de Souza, Adijailton Jose ^[1] ; Mattos, Bianca Braz ^[2] ; Tornisielo, Valdemar Luiz ^[3] ; Regitano, Jussara Borges ^[1]

Afiliação do(s) autor(es)

^[1] Univ Sao Paulo, Luiz de Queiroz Coll Agr ESALQ, Dept Soil Sci, CP 09, BR-13418260 Piracicaba, SP - Brazil

^[2] Brazilian Agr Res Corp, Embrapa Soils, BR-22460000 Rio De Janeiro, RJ - Brazil

^[3] Univ Sao Paulo, Ctr Nucl Energy Agr CENA, BR-03178200 Piracicaba, SP - Brazil

• Tipo de documento: Artigo Científico
• Fonte: Chemosphere; v. 287, n. 3 JAN 2022.
• Citações Web of Science: 1

Resumo

Agrowaste biochars {[}sugarcane straw (SS), rice husk (RH), poultry manure (PM), and sawdust (SW)] were synthesized at different pyrolysis temperatures (350, 450, 550, and 650 degrees C) to evaluate their potential to retain highly mobile herbicides, such as hexazinone and tebuthiuron that often contaminate water resources around sugarcane plantations. A new low field nuclear magnetic resonance approach based on decay due to diffusion in internal magnetic field (NMR-DDIF) was successfully used to determine biochar's porosity and specific surface area (SSA) to clear the findings of this work. SSA of pores with diameters >5.0 mu m increased with pyrolysis temperatures and seemed to dictate biochar's retention, which was >70% of the applied amounts at 650 degrees C. These macropores appear to act as main arteries for herbicide intra-particle diffusion into smaller pores, thus enhancing herbicides retention. Biochar granulometry had little, but herbicide aging had a significant effect on sorption, mainly of tebuthiuron. However, soils amended with 10,000 kg ha-1 of the biochars showed low sorption potential. Therefore, higher than usual biochar rates or proper incorporation strategies, i.e., surface incorporation, will be needed to remediate areas contaminated with these highly mobile herbicides, thus pre-cluding their leaching to groundwaters. (AU)

• Processo FAPESP: 14/18293-7 - Dinâmica de tebuthiuron e hexazinona em solos sob aplicação de biocarvão
• Beneficiário: Letícia de Pierri
• Modalidade de apoio: Bolsas no Brasil - Doutorado