Avaliação da toxicidade do lodo de estação de tratamento de água e esgoto, antes e após vermicompostagem, usando teste de germinação com semente de alface (Lactuca sativa)

• Autor(a) principal: Tavares, Rosangela Gomes
• Data de Publicação: 2019
• Outros Autores: Sobrinho, Maurício Alves da Motta, Pereira, Luciana, Côrrea, Marcus Metri, Arruda, Valmir Cristiano Marques de, Melo, Rafael Roney Camara de
• Tipo de documento: Artigo
• Idioma: por
• Título da fonte: Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos)
• Texto Completo: http://hdl.handle.net/1822/60925
• topic: WTP sludge; WWTP sludge; Phytotoxicity; Lactuca sativa

The objective of this work was to evaluate the phytotoxicity of elutriate obtained from WTP and WWTP sludge before and after treatment by vermicomposting (TVC). The tests used the interfacial water of pure and consorted sludge in the 75, 50 and 25% of the respective sludge (mixture of WTP and WWTP sludge) sludges. To evaluate the toxicity were used seeds of lettuce, Lactuca sativa. The lettuce seeds were placed in Petri dishes with filter paper and moistened with 4 mL of elutriate solution, the plates were sealed with plastic film, to avoid evaporation of the elutriate, and later with aluminum foil, to preserve the absence of light, kept in a BOD type incubator at 25 ± 1 ºC for 120 hours. The design was completely randomized with 15 samples of each sludge mixture, before and 15 after the TVC, 5 dilutions (10, 25, 50, 75 and 100%) and three replications, totaling 450 sample plots and 6 plots of controls. Al concentrations were determined in all samples and controls. The toxicity test showed that there was an increase in germination index after CVT; As well as the elutriatro, with the highest dilution of 10% and lower Al concentration, obtained a more expressive result, showing that the germination of the seeds was reduced proportionally to the increase of aluminum concentrations present in the elutriate.