Universidade de Trás-os-Montes e Alto Douro, Escola de Ciências e Tecnologia, 5000-801 Vila Real, Portugal; C-MADE - Centre of Materials and Building Technologies, University of Beira Interior, 6201-001 Covilhã, Portugal.
Universidade de Trás-os-Montes e Alto Douro, Escola de Ciências e Tecnologia, 5000-801 Vila Real, Portugal; C-MADE - Centre of Materials and Building Technologies, University of Beira Interior, 6201-001 Covilhã, Portugal.
Sci Total Environ. 2014 Sep 15;493:463-71. doi: 10.1016/j.scitotenv.2014.05.129. Epub 2014 Jun 21.
Wastewater and greywater have different scales of end-uses in irrigation in Portugal. Wastewater is treated in a central wastewater treatment plant and reused in public/private large areas of irrigation, like agriculture, public gardens and golf courses. On the contrary, greywater reuse is generally applied in in situ small scales, treated and used in the same place, generally in the production site. The main aim of this paper is to compare the two types of systems: a wastewater centralized reuse system (WWCRS) and a greywater decentralized reuse system (GWDRS) in terms of water quality, energy consumption and CO2 emissions. In this paper, the main characteristics of both streams are presented and the degree of treatment required in each stream is analyzed. The advantages and disadvantages of its reuse in different scales, in terms of water quality, energy consumption and CO2 emissions are discussed. A methodology to calculate the energy consumptions and CO2 emissions related to wastewater treatment that may be applied in different cases is presented. A hypothetical example of the two systems: one referring to a WWCRS and the other to a GWDRS is presented. The energy consumption and the CO2 emissions are analyzed and compared. The WWCRS needs a higher degree of treatment and so it spends more energy and leads to more CO2 emissions to the environment than the GWDRS that consumed between 11.8 and 37.5% of the energy consumed in the WWCRS considering the same number of inhabitants served.
葡萄牙的灌溉中，污水和灰水有不同的用途。污水在中央污水处理厂进行处理，然后在公共/私人大型灌溉区（如农业、公共花园和高尔夫球场）中再利用。相比之下，灰水再利用通常在现场小规模应用，就地处理和使用，通常在生产现场。本文的主要目的是比较两种系统：集中式污水再利用系统（WWCRS）和分散式灰水再利用系统（GWDRS）在水质、能源消耗和二氧化碳排放方面的差异。本文介绍了这两种废水的主要特征，并分析了每种废水所需的处理程度。讨论了在不同规模下，从水质、能源消耗和二氧化碳排放方面考虑，其再利用的优缺点。提出了一种计算与废水处理相关的能源消耗和二氧化碳排放的方法，可应用于不同情况。提出了这两种系统的一个假设示例：一个是 WWCRS，另一个是 GWDRS。对能源消耗和二氧化碳排放进行了分析和比较。WWCRS 需要更高程度的处理，因此它比 GWDRS 消耗更多的能源，并导致更多的二氧化碳排放到环境中，考虑到相同数量的服务居民，GWDRS 消耗的能源仅为 WWCRS 的 11.8%至 37.5%。
