Abstract Decentralized systems for treatment of domestic effluents have been suggested as a sustainable alternative for situations where conventional sanitation has not yet been established. This study compares three possible scenarios for the destination of separated blackwater (BW) and kitchen waste (KW), being: co-digestion of both (BWK discharge of BW into a septic-tank and composting of the KW (scenario 2) and discharge of the BW into a septic-tank and of the KW at a solid waste disposal (scenario 3, actually the most common situation in large part of Brazil). In order to compare the scenarios, the use of equivalent amounts of water and fertilizer was considered in scenarios 2 (septic-tank and composting) and 3 (septic-tank and landfill), in order to maintain functional equivalence with that of scenario 1 (co-digestion and reuse). In scenario 1, treatment of the organic waste in an Upflow Anaerobic Sludge Blanket (UASB) reactor, for a period of 6 (scenario 1A) or 12 days (scenario 1B), with effluent recycling, was considered. In order to verify the effect of the use of energy in scenario 1 and to verify the effect of the degree of treatment realized in scenarios 2 and 3, a sensitivity analysis was realized for the parameters energy use and COD removal. The management of the sub-products in scenario 1 resulted in emission gains, when compared to scenarios 2 and 3, where the need to include amounts of water and fertilizer, to obtain functional equivalence, increased the environmental impacts associated to these scenarios. However the energy consumption increased the impact levels in scenario 1 and, overall, scenario 2 (septic-tank and composting), obtained the lowest impact scores, presenting the most advantageous scenario, among the three scenarios studied, from an environmental point of view, considering the restrictions as defined here, followed by scenarios 3 (septic-tank and landfill), 1A (6-day co-digestion and reuse) and 1B (12-day co-digestion and reuse). After the sensitivity analysis the influence of energy consumption on the impact categories for scenario 1 became evident, whereas, on the other hand, the degree of pollution removal from the blackwater did not change the overall results, making thus minimizing energy consumption during treatment more relevant than improving pollutant removal, in order to minimize the environmental impacts.

中文翻译：

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使用生命周期评估方法比较黑水和厨余现场再利用的不同场景

摘要 用于处理生活污水的分散式系统已被建议作为传统卫生尚未建立的情况的可持续替代方案。本研究比较了分离后的黑水 (BW) 和厨房垃圾 (KW) 的三种可能目的地，即：两者共同消化（BWK 将 BW 排放到化粪池中，并将 KW 堆肥（场景 2）和排放将 BW 放入化粪池，将 KW 放入固体废物处理处（场景 3，实际上是巴西大部分地区最常见的情况）。为了比较这些场景，使用等量的水和肥料在情景 2（化粪池和堆肥）和 3（化粪池和垃圾填埋场）中考虑，以保持与情景 1（共同消化和再利用）的功能等效。在情景 1 中，考虑在上流式厌氧污泥毯 (UASB) 反应器中处理有机废物，时间为 6（情景 1A）或 12 天（情景 1B），并进行污水回收。为了验证场景1中能源使用的效果以及场景2和3中实现的处理程度的效果，对能源使用和COD去除参数进行了敏感性分析。与情景 2 和情景 3 相比，情景 1 中子产品的管理导致排放增益，情景 2 和情景 3 需要包括水和肥料的数量，以获得功能等效，增加了与这些情景相关的环境影响。然而，能源消耗增加了情景 1 和总体情景 2（化粪池和堆肥）中的影响水平，在所研究的三个情景中，从环境的角度来看，考虑到此处定义的限制，获得了最低的影响评分，呈现了最有利的情景，其次是情景 3（化粪池和垃圾填埋场）、1A（6 天合作） -消化和再利用）和 1B（12 天共同消化和再利用）。在敏感性分析之后，能源消耗对情景 1 影响类别的影响变得明显，而另一方面，从黑水中去除污染的程度并没有改变整体结果，从而使处理过程中的能源消耗最小化更加相关而不是提高污染物去除率，以尽量减少对环境的影响。考虑此处定义的限制，然后是情景 3（化粪池和垃圾填埋场）、1A（6 天共同消化和再利用）和 1B（12 天共同消化和再利用）。在敏感性分析之后，能源消耗对情景 1 影响类别的影响变得明显，而另一方面，从黑水中去除污染的程度并没有改变整体结果，从而使处理过程中的能源消耗最小化更加相关而不是提高污染物去除率，以尽量减少对环境的影响。考虑此处定义的限制，然后是情景 3（化粪池和垃圾填埋场）、1A（6 天共同消化和再利用）和 1B（12 天共同消化和再利用）。在敏感性分析之后，能源消耗对情景 1 影响类别的影响变得明显，而另一方面，黑水的污染去除程度并没有改变整体结果，从而使处理过程中的能源消耗最小化更加相关而不是提高污染物去除率，以尽量减少对环境的影响。