Evaluation of the environmental life cycle of an STP that employs a low-rate trickling filter as post-treatment of a UASB reactor and different sludge-management alternatives

This study aimed to undertake an environmental life cycle assessment (LCA) of a sewage treatment plant (STP) equipped with low-rate trickling filters (TFs) as post-treatment upflow anaerobic sludge blanket (UASB). The STP is located in South Brazil and uses landfill agriculture sludge-disposal alternatives. evaluation was performed using the LCA technique SimaPro® 9 software. results revealed that gases methane (CH4) sulfur dioxide (SO2), emitted into atmosphere after partial burning biogas flares, are mainly responsible for impacts categories global warming (GW) terrestrial acidification (TA), respectively. Due low rate hydraulic application TFs, nitrous oxide (N2O) emissions stood out due their high impact category stratospheric ozone depletion (SOD). use obtained greater potential compared landfills five eight evaluated. main agricultural were human toxicity (HT), concentration zinc present sludge, TA, emission ammonia (NH3) during hygienization sludge. In turn, positive aspects avoided products, such urea, phosphate fertilizer limestone. contribute discussion sewage-treatment processes, well sludge-management alternatives used developing countries.