RESUMO:O presente trabalho avaliou as condições de reúso dos efluentes finais de dois sistemas de tratamento biológico de esgotos: um reator UASB e um sistema de lodo ativado frente aos padrões recomendados da Organização Mundial de Saúde (OMS) e os critérios de qualidade de água para irrigação. As variáveis avaliadas foram pH; CE; Ca 2+ ; Mg 2+ ; Na + ; Cl -; NTK; Fósforo total; DQO; Turbidez; SST; amônia; coliformes termotolerantes e ovos de helmintos; RAS; e salinidade. Os resultados demonstraram que os sistemas só cumprem parcialmente os requisitos para reúso agrícola. O sistema UASB apresentou SST e turbidez como limitantes na irrigação localizada, concentração de coliformes apenas para irrigação restrita em subsuperfície, NTK acima de 30 mg.L -1 e a contagem > 1,0 ovo.L -1 de helmintos que inviabiliza o reúso. O sistema UCT apresentou menos limitações de acordo com os parâmetros avaliados, com inviabilidade de reúso direto principalmente devido à turbidez, coliformes e ovos de helmintos. PALAVRAS-CHAVE:Lodo Ativado; Reatores; Reúso Agrícola; UASB. QUALIT Y OF EFFLUENTS FROM UASB AND UCT BIOLOGICAL TREATMENT SYSTEMS FOR AGRICULTURAL REUSEABSTRACT: The reuse of affluents from two biological sewage treatment systems is assessed. The study comprised a Upflow Anaerobic Sludge Blanket (UASB) reactor and an activated sludge system according to standards recommended by the World

Aim This study aimed to develop a Trophic State Index that simulates the cumulative impact in 18 reservoirs in the Banabuiú basin, located in the semiarid region of the State of Ceará. Methods Analyses were made for physical (temperature, transparency and turbidity), chemical (dissolved oxygen, pH and total phosphorus) and biological (chlorophyll-a) variables as indicators of reservoir water quality. Data used in this study were made available by the Water Resources Management Company of the State of Ceará (COGERH), in the years between 2010 and 2013. An adaptation was developed for trophic classification (TSISA), incorporating the three most relevant variables for trophic evaluation, total phosphorus, chlorophyll-a and transparency. For interpreting the data set, we used multivariate statistics as Hierarchical Cluster Analysis (HCA) and Factor Analysis/Principal Component Analysis (PCA). Results The similarity of Banabuiú basin reservoirs in relation to water eutrophication gave rise to three distinct groups: I, II and III consisting of nine, four and five reservoirs, respectively. The calculation of minimum and maximum values and percentiles of the correlated parameters defined four classes of trophic state; it was observed that the reservoirs in the group I showed trophic classification predominantly between oligotrophic (54.7%), mesotrophic (30.2%), group II, eutrophic (44.4%) and hypertrophic (33.3%) and those of the group III, eutrophic (39.1%) and hypertrophic (60.9%). Conclusions The TSISA presented a simple methodology and easy interpretation of the data, grounded in the quality of water of reservoirs located in the semiarid region of Ceará. Thus, its use can contribute for the reduction of errors in the inference of the trophic state of reservoirs in this region and should be considered as an indicator for more detailed studies.