Pyrolysis temperature and biochar redox activity on arsenic availability and speciation in a sediment

Autor(es)

Soares, Matheus B. ; Duckworth, Owen W. ; Styblo, Miroslav ; Cable, Peter H. ; Alleoni, Luis R. F.

• Tipo de documento: Artigo Científico
• Fonte: JOURNAL OF HAZARDOUS MATERIALS; v. 460, p. 13-pg., 2023-10-15.

Resumo

Biochar is widely used for water and soil remediation in part because of its local availability and low production cost. However, its effectiveness depends on physicochemical properties related to its feedstock and pyrolysis temperature, as well as the environmental conditions of its use site. Furthermore, biochar is susceptible to natural aging caused by changes in soil or sediment moisture, which can alter its redox properties and interactions with contaminants such as arsenic (As). In this study, we investigated the effect of pyrolysis temperature and biochar application on the release and transformations of As in contaminated sediments subjected to redox fluctuations. Biochar application and pyrolysis temperature played an important role in As species availability, As methylation, and dissolved organic carbon concentration. Furthermore, successive flooding cycles that induced reductive conditions in sediments increased the As content in the solution by up to seven times. In the solid phase, the application of biochar and the flooding cycle altered the spatial distribution and speciation of carbon, iron (Fe) and As. In general, the application of biochar decreased the reduction of Fe(III) and As(V) after the firstcycle of flooding. Our results demonstrate that the flooding cycle plays an important role in the reoxidation of biochar to the point of enhancing the immobilization of As. (AU)

• Processo FAPESP: 20/13700-4 - Efeito do carbono pirogênico nas espécies de arsênio e sua interação com óxido de ferro biogênico em sedimento contaminado remediado com biocarvão
• Beneficiário: Matheus Bortolanza Soares
• Modalidade de apoio: Bolsas no Exterior - Estágio de Pesquisa - Doutorado
• Processo FAPESP: 19/06897-9 - Biogeoquímica de arsênio e chumbo em solo remediado com biocarvão
• Beneficiário: Matheus Bortolanza Soares
• Modalidade de apoio: Bolsas no Brasil - Doutorado