RESUMO
Municipal sewage sludge is a waste with high organic load generated in large quantities that can be treated by biodegradation techniques to reduce its risk to the environment. This research studies vermicomposting and vermicomposting after composting of sewage sludge with the earthworm specie Eisenia andrei. In order to determine the effect that earthworms cause on the microbial dynamics depending on the treatment, the structure and activity of the microbial community was assessed using phospholipid fatty acid analysis and enzyme activities, during 112days of vermicomposting of fresh and composted sewage sludge, with and without earthworms. The presence of earthworms significantly reduced microbial biomass and all microbial groups (Gram+ bacteria, Gram- bacteria and fungi), as well as cellulase and alkaline phosphatase activities. Combined composting-vermicomposting treatment showed a lesser development of earthworms, higher bacterial and fungal biomass than vermicomposting treatment and greater differences, compared with the control without earthworms, in cellulase, ß-glucosidase, alkaline and acid phosphatase. Both treatments were suitable for the stabilization of municipal sewage sludge and the combined composting-vermicomposting treatment can be a viable process for maturation of fresh compost.
Assuntos
Biodegradação Ambiental , Oligoquetos , Esgotos/microbiologia , Eliminação de Resíduos Líquidos/métodos , Fosfatase Alcalina/química , Animais , Bactérias , Biomassa , Carbono/química , Celulase/química , Ácidos Graxos/química , Fungos , Fosfolipídeos/química , Fósforo/química , Solo , Espanha , Águas Residuárias , Purificação da Água/métodosRESUMO
Se estudian sujetos expuestos ocupacionalmente por más de 10 años a radiaciones electromagnéticas no ionizantes. Se realizaron determinaciones de inmunocomplejos; cuantificación de inmunoglobulinas A, G y M, y prueba de roseta activa y espontánea para estudiar inmunidad humoral y celular, así como otras pruebas. Se utilizó un grupo control con edad promedio similar al grupo estudiado y no expuesto a radiaciones. Se evidenciaron cambios en la inmunidad humoral, dados por alteraciones encontradas en la IgG e IgA. Se comprobó la disminución de la roseta activa y espontánea en el grupo expuesto en relación con el grupo control