Abstract:
<p align="justify"> Human wastes are a permanent challenge to the environment. Current research has evaluated the amount of copper metal in the sewerage and in the sludge of the Sewerage Treatment Stations (STSs) of Maringa PR Brazil. Sample collection was undertaken at the STSs and samples were digested with nitric acid at a reduced volume. Biosolid samples, previously dried and ground, at constant weights, were digested by aqua regia. Determination of metal concentrations was made by atomic absorption spectrometry. The pH, nitrogen, carbon, and organic matter (OM) values were determined by the respective classical methods. Total average were: a) Cu in affluent sewerage 0.077 and effluent sewerage 0.058 .&#956;g.ml^-1. b) biosolid; Cu = 0.74 mg.g^-1; pH= 3.38; N = 3.24 %; C = 24.5 % e OM= 42.1 %. Variance analysis of the experimental values, and taking into consideration the variation sources of STSs and collection time showed that no significant difference between the values of copper concentration, N (%), C (%), and organic matter (%) respectively existed in both variation sources. The total average rate of copper concentration of STSs is higher than the international world average value found in the relating literature. Amounts of organic matter and the C: N (carbon: nitrogen) proportions of sewage sludge are appropriate for soil application; </p>