Search

Data centers are estimated to have the fastest growing carbon footprint from across the whole information and communication technology (ICT) sector. Evaluating the performance of data centers in terms of energy efficiency and sustainability is becoming an increasingly important matter for organizations and governments (e.g., for regulation or reputation purposes). It nonetheless remains difficult to achieve such evaluation, as data centers imply to take into consideration a wide range of dimensions and stakeholders. Even though a wide range of sustainability performance indicators exist in the literature, there is still a lack of frameworks to help data center stakeholders (spanning from data center owners, governmental regulators to engineers/field operators) to evaluate and understand how a data center performs in terms of sustainable development/behavior. Our research work proposes such a framework, whose originality lies in the combination of state-of-the-art sustainability metrics with the biomimicry commandments of eco-mature system, which enables holistic sustainability assessment of data centres. From a theoretical perspective, the proposed model is designed based on a benefit-cost analysis using the Analytic Hierarchy Process (AHP) technique. This approach allows data center stakeholders for specifying their own preferences and/or expertise in the comparison process, whose practicability is demonstrated in this paper considering three data center candidates, which are respectively located in France, Germany and Sweden. • A new model for comparing data center sustainability performance is proposed. • The model makes use of state-of-the-art sustainability metrics together with biomimicry lessons. • The model is designed based on a benefit-cost approach using the AHP technique. • A comparison study is carried out with three distinct data center candidates. [ABSTRACT FROM AUTHOR]

To tackle water micropollutant pollution, the development of an advanced wastewater treatment is necessary and should be supported by an environmental evaluation to guide decision-makers. Life cycle assessment (LCA) methodology has been applied in the literature for several technologies and highlighted the variability of results (e.g. site-specific conditions) and the limited (eco-)toxicity benefits compared to additional operating impacts. In this study, the LCA of an activated carbon (AC) adsorption process based on a fluidized bed (limiting AC usage) was performed to determine its optimal operating conditions (dosage, use of micro-grain – μGAC or powder – PAC) and environmental benefits compared to the common ozonation process. This study was based on pilot processes installed at the Seine Centre treatment plant (France), using sensitivity analyses to identify the conditions for choosing a technology. For the seven scenarios (fluidized bed with 10 and 20 mg/L, both for PAC and μGAC; ozonation with 0.6 and 0.9 gO 3 /gDOC; and pre-ozonation combined with μGAC), the operational impacts generated (energy and material use) and the impacts avoided (micropollutant removal) were evaluated for climate change, freshwater ecotoxicity and human toxicity (USEtox characterization factors for micropollutants complemented with literature data). The LCA results showed that the fluidized bed process should preferably be operated with μGAC rather than PAC. The advantage of μGAC adsorption compared to ozonation is negligible but could nevertheless be significant in European countries with a significant share of coal-based electricity (i.e. all countries except Sweden and France). As in most of the previous works, the (eco)toxicity impacts avoided were found to be negligible, but other substances, such as hormones and oxidation by-products, should be further considered and characterized to better represent the treatment performances. The combination of ozonation and μGAC adsorption on a fluidized bed is a promising option to efficiently remove micropollutants, as well as oxidation by-products, while keeping the impacts generated within a reasonable range. This paper presented valuable results to support the eco-design of advanced wastewater treatment (both in terms of operating conditions and targeted substances) but should be complemented with large-scale evaluations (e.g. using consequential LCA) and better impact characterization of micropollutants. • Powder and micro-grain activated carbon (AC) in fluidized bed pilot were evaluated. • The use of micro-grain (μGAC) has lower environmental impacts than other AC types. • Its impacts are similar than ozonation process, tested in the same treatment plant. • Pre-ozonation and μGAC process is promising due to potential oxidation by-products. • Threshold values are provided to guide decisions depending on operating conditions. [ABSTRACT FROM AUTHOR]