This study aimed to carry out the Life Cycle Analysis (LCA) targeting to decide the better management system for sludge from both Activated Sludge Process (ASP) and from Upflow Anaerobic Sludge Blanket (UASB). Using the SimaPro^® software, three post-use scenarios were applied to this process for each type of sludge: Scenario A, which consisted of the option of disposing of UASB sludge in a sanitary landfill; Scenario B, in anaerobic digestion (AD) with the generation of biogas and electricity and use of digested sludge; and Scenario C, the use of UASB sludge as an agricultural fertilizer. Besides, we carried out the analysis of heavy metals in the sludge before and after the AD using the Scanning Electron Microscopy. The elements found with a marked presence in the treatment of UASB and ASP sludge samples, before and after AD, were, among others: Oxygen, Carbon, Aluminum, Silicon, and Iron. The energy avoided for UASB sludge is 0.0502 MJ. For activated sludge, it is 0.00173 MJ. The use of activated sludge as an agricultural fertilizer (Scenario C) presented the best performance in eight of the eleven categories due to the presence of products avoided in the process.

本研究旨在进行生命周期分析 (LCA)，旨在确定对来自活性污泥法 (ASP) 和来自上流式厌氧污泥床(UASB) 的污泥的更好管理系统。使用 SimaPro ^®在该软件中，针对每种类型的污泥，将三个使用后场景应用于该过程：场景 A，包括在卫生垃圾填埋场中处置 UASB 污泥的选项；情景 B，在厌氧消化 (AD) 中，产生沼气和电力以及使用消化污泥；情景 C，使用 UASB 污泥作为农业肥料。此外，我们使用扫描电子显微镜对 AD 前后污泥中的重金属进行了分析。在 AD 之前和之后，在 UASB 和 ASP 污泥样品处理中发现的显着存在的元素包括：氧、碳、铝、硅和铁。UASB 污泥避免的能量为 0.0502 MJ。对于活性污泥，它是 0.00173 MJ。