Cassava is a prominent crop in Brazil, with high production and consumption. From their processing flour or starch comes as final products, from different types of processing. In this context, waste is generated without proper disposal, such as handling and wastewater from puba. These effluents are rich in organic matter, with low pH and cyanide presence. Thus, the objective of this study was to evaluate the efficiency of biological treatment of effluents as a form of sustainable incentive to flour producing units. The experiment consisted of three systems, using facultative lagoons (L1, L2 and L3) and UASB reactors (U1, U2 and U3) each treated with the following proportions: (A1) raw sewage and puba water (6:4); (A2) raw sewage and cassava wastewater (9:1) and (A3) raw sewage, puba water and manipueira (6 3:1), which were prepared weekly by a volume of 150 liters. All were monitored and evaluated through physical and chemical analysis. The characterization of the cassava wastewater presented the following results: pH 4,51; total cyanide 297 mg. L-1 and COD of 62.493 mg. L-1. While puba water had a pH of 3,85; total cyanide 27.6 mg. L-1 and COD of 11.124 mg. L-1. The pH stabilization of the lagoons in relation to the tributaries presented in all five treatment start cycles within the recommended for the buffer capacity of the UASB reactors. Regarding the concentration of CN-, the lagoons (L1, L2 and L3) removed, respectively, 76%, 66% and 71%. For COD, overall removal values were 66% for system 1, 63% for system 2 and 59% removal for system 3. The treated effluents from the UASB reactors showed significant levels of NTK, NH4+, Pt and PO43- for reuse in fertigation. Therefore the treatment systems showed technical and economical viability in the use of biological processes in the elevation of the pH and the removal of cyanide, as well as in the environmental quality with the removal of most of the biodegraded organic matter
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