Effects of capping on microbial populations and contaminant immobilization in an old unlined landfill

Autor(es)

Morita, Alice Kimie Martins ; Sakamoto, Isabel Kimiko ; Varesche, Maria Bernadete Amancio ; Wendland, Edson

• Tipo de documento: Artigo Científico
• Fonte: Environmental Science and Pollution Research; v. 30, n. 26, p. 15-pg., 2023-06-01.

Resumo

This research aimed at evaluating the effects of capping on the mitigation of impacts generated by a closed unlined landfill in SAo Carlos, SP, Brazil. Physicochemical and microbiological analyses (16S rRNA sequencing) of buried solid waste samples were performed, in capped and uncapped areas. Even though leachate pockets could still be encountered in capped areas, the capping construction reduced oxygen availability and created more reducing conditions, propitiating the development of sulfate-reducing bacteria and possibly contributing to the precipitation of the metals Pb, Cd, Ni, Co, As, and Zn as metal sulfides, causing their immobilization. The microbial populations adapted to the anaerobic conditions created under capped zones belonged to the phyla Firmicutes, Chloroflexi, and Euryarchaeota and the genera Methanosaeta, Hydrogenispora, Smithella, and Gelria. Differently, the phyla Acidobacteria, Proteobacteria, Bacteroidetes, and Actinobacteria were more abundant in samples from the uncapped zones, in which the abundance of different genera varied homogeneously. Methanogenic activity was not impaired by the intervention measure, as assessed by the specific methanogenic activity (SMA). Capping of old unlined landfills brings benefits to the immobilization of metals and does not impair microbial degradation, being effective for the mitigation of impacts on soils and water resources. (AU)

• Processo FAPESP: 15/03806-1 - Disponibilidade hídrica e riscos de contaminação em áreas de afloramento do Sistema Aquífero Guarani
• Beneficiário: Edson Cezar Wendland
• Modalidade de apoio: Auxílio à Pesquisa - Programa BIOEN - Temático
• Processo FAPESP: 18/24615-8 - Efeitos de impermeabilização superficial parcial na mobilização de contaminantes e na degradação microbiana em depósito de resíduos desativado
• Beneficiário: Alice Kimie Martins Morita
• Modalidade de apoio: Bolsas no Brasil - Doutorado