Reliability analysis of wastewater treatment plants

摘要: This article presents a reliability analysis of 166 full-scale wastewater treatment plants operating in Brazil. Six different processes have been investigated, comprising septic tank+anaerobic filter, facultative pond, anaerobic pond+facultative activated sludge, upflow sludge blanket (UASB) reactors alone and UASB followed by post-treatment. A methodology developed Niku et al. [1979. Performance process reliability-based design. J. Water Pollut. Control Assoc., 51(12), 2841-2857] is used for determining the coefficients (COR), terms compliance effluent biochemical oxygen demand (BOD), chemical (COD), total suspended solids (TSS), nitrogen (TN), phosphorus (TP) fecal or thermotolerant coliforms (FC) with discharge standards. The design concentrations necessary to meet prevailing standards expected percentages calculated from COR obtained. results showed that few plants, under observed conditions, would be able present reliable performances considering analyzed also discusses importance understanding lognormal behavior data setting up standards, interpreting monitoring legislation.