Assessment of combined treatment of landfill urban solid waste leachate and sewage using Danio rerio and Daphnia similis.

The co-treatment from Morro do Céu landfill leachate with domestic sewage in the Icaraí STP was monitored with regard to the behavior of toxicity of its inflows and outflow. Leachate not exceeded 1.5% in volume in the plant. The acute ecotoxicological tests showed that, although leachate is far more harmful to D. rerio (LC50 approximately = 4) and D. similis (LC50 approximately = 5) than sewage (LC50 approximately = 62; LC50 approximately = 22), statistically the mixture of leachate with sewage did not result in a more toxic inflow (LC50 approximately = 57; LC50 approximately = 12) for treatment than raw sewage. After treatment, the outflow toxicity (LC50 approximately = 76; LC50 approximately = 16) complied with the environmental laws.