Human-induced changes in water consumption and global warming are likely to reduce the species richness of freshwater ecosystems. So far, these impacts have not been addressed in the context of life cycle assessment (LCA). Here, we derived characterization factors for water consumption and global warming based on freshwater fish species loss. Calculation of characterization factors for potential freshwater fish losses from water consumption were estimated using a generic species-river discharge curve for 214 global river basins. We also derived characterization factors for potential freshwater fish species losses per unit of greenhouse gas emission. Based on five global climate scenarios, characterization factors for 63 greenhouse gas emissions were calculated. Depending on the river considered, characterization factors for water consumption can differ up to 3 orders of magnitude. Characterization factors for greenhouse gas emissions can vary up to 5 orders of magnitude, depending on the atmospheric residence time and radiative forcing efficiency of greenhouse gas emissions. An emission of 1 ton of CO2 is expected to cause the same impact on potential fish species disappearance as the water consumption of 10-1000 m(3), depending on the river basin considered. Our results make it possible to compare the impact of water consumption with greenhouse gas emissions.
Water-saving cultivation in wheat (Triticum aestivum L.) is an important technique for achieving high yield and high water use eficiency (WUE) in the North China Plain (NCP) where water resources are in shortage. In order to determine the effects of supplemental irrigation based on soil water content on crop evapotranspiration (ET), DM, grain yield and WUE in wheat, treatments were designed to vary the relative soil water content at jointing and anthesis stages: I-70 (70%, 70%) and I-75 (75%, 75%) with rain-fed (I-0) and traditional irrigation (I-ck) as contrasts. The results indicated that the irrigation amount of I-70 and I-75 were significantly lower than that of I-ck by 45.1 to 132.4 mm, but soil water depletion increased by 23.5 to 35.4 mm. Although the total ET throughout the growing season (ETt) of I-75 was less than that of I-ck, the ratio to ETt from anthesis to maturity increased significantly. The DM partitioning ratio was decreased in vegetable organs, but increased in grain for I-75 compared with I-ck. The grain yield for I-75 was significantly higher than that of I-0 and I-70, whereas nonsignificant difference was observed between I-75 and I-ck, and the WUE and irrigation water use efficiency of I-75 were higher than those of Ick by 11.0% and 87.4% in 2008-2009 and 3.5% and 34.0% in 2009-2010. Thus, I-75 can be developed as an optimal water-saving irrigation regimes in the NCP.
Life cycle assessment (LCA) has been used to assess freshwater-related impacts according to a new water footprint framework formalized in the ISO 14046 standard. To date, no consensus-based approach exists for applying this standard and results are not always comparable when different scarcity or stress indicators are used for characterization of impacts. This paper presents the outcome of a 2-year consensus building process by the Water Use in Life Cycle Assessment (WULCA), a working group of the UNEP-SETAC Life Cycle Initiative, on a water scarcity midpoint method for use in LCA and for water scarcity footprint assessments.In the previous work, the question to be answered was identified and different expert workshops around the world led to three different proposals. After eliminating one proposal showing low relevance for the question to be answered, the remaining two were evaluated against four criteria: stakeholder acceptance, robustness with closed basins, main normative choice, and physical meaning.The recommended method, AWARE, is based on the quantification of the relative available water remaining per area once the demand of humans and aquatic ecosystems has been met, answering the question “What is the potential to deprive another user (human or ecosystem) when consuming water in this area?” The resulting characterization factor (CF) ranges between 0.1 and 100 and can be used to calculate water scarcity footprints as defined in the ISO standard.After 8 years of development on water use impact assessment methods, and 2 years of consensus building, this method represents the state of the art of the current knowledge on how to assess potential impacts from water use in LCA, assessing both human and ecosystem users’ potential deprivation, at the midpoint level, and provides a consensus-based methodology for the calculation of a water scarcity footprint as per ISO 14046.
The objective is to develop a measure of perceived risk underlying urban water consumption (UWC) that is applicable in situations of drought and strong rainfall. First, we analyse existing scales and the dimensions involved in perceived risk related to UWC. Second, we test our proposed scale using two studies. Study 1 was carried out in Spain in 2012 (n = 701) during a period of heavy rains. Study 2 was performed in 2014 in the semi-arid area of Spain (n = 477) during a long drought period. The proposed scale has three dimensions (impact, time-related and control) and high reliabilities (0.86-0.89), validities (convergent, discriminant, construct) and is invariant between both rainy and dry periods. UWC Perceived Risk Scale fits into a Pearson 'Type VI distribution', which can serve scholars and technicians in measuring urban water perceived risk in their researches and urban water management projects.
Consumption of ultrapure water (UPW) during semiconductor manufacturing processes is a very important topic. A new water-dispensing arm design uses a small volume of UPW to remove slurry residue and defects inside pad grooves. This innovative water conditioning arm, in contrast to the conventional atomizer and diamond disc, not only reduces UPW consumption by 87% but also reduces scratch defects caused by diamond abrasive particles. The small water volume arm conditioning system injects UPW with diameters at micro levels. Experimental results show that oxide film removal amount under continuous polishing conditions is maintained at 716 A even after 20 runs. The removal amount and profile not only is maintained but improved by over 2% in comparison with the conventional atomizer under no-dressing conditions. Finally, using a water pump to increase the water pressure up to 50 km/cm 2 and treating for 5 s resulted in only 0.5-mm dishing for the IC1010 polish pad.
The shortage of agricultural water from freshwater sources is a growing concern because of the relatively large amounts needed to sustain food production for an increasing population. In this context, an impact assessment methodology is indispensable for the identification and assessment of the potential consequences of freshwater consumption in relation to agricultural water scarcity. This paper reports on the consistent development of midpoint and endpoint characterisation factors (CFs) for assessing these impacts.Midpoint characterisation factors focus specifically on shortages in food production resulting from agricultural water scarcity. These were calculated by incorporating country-specific compensation factors for physical availability of water resources and socio-economic capacity in relation to the irrigation water demand for agriculture. At the endpoint, to reflect the more complex impact pathways from food production losses to malnutrition damage from agricultural water scarcity, international food trade relationships and economic adaptation capacity were integrated in the modelling with measures of nutritional vulnerability for each country.The inter-country variances of CFs at the midpoint revealed by this study were larger than those derived using previously developed methods, which did not integrate compensation processes by food stocks. At the endpoint level, both national and trade-induced damage through international trade were quantified and visualised. Distribution of malnutrition damage was also determined by production and trade balances for commodity groups in water-consuming countries, as well as dependency on import ratios for importer countries and economic adaptation capacity in each country. By incorporating the complex relationships between these factors, estimated malnutrition damage due to freshwater consumption at the country scale showed good correlation with total reported nutritional deficiency damage.The model allows the establishment of consistent CFs at the midpoint and endpoint for agricultural water scarcity resulting from freshwater consumption. The complex relationships between food production supply and nutrition damage can be described by considering the physical and socio-economic parameters used in this study. Developed CFs contribute to a better assessment of the potential impacts associated with freshwater consumption in global supply chains and to life cycle assessment and water footprint assessments.
The purpose of this research was the characterization and improvement of the quality of water used for human consumption of unregulated/regulated water sources located in the Cameron/Tuba City abandoned uranium mining area (NE Arizona, western edge of the Navajo Nation). Samples were collected at six water sources which included regulated sources: Wind Mill (Tank 3T-538), Badger Springs and Paddock Well as well as unregulated sources: Willy Spring, Water Wall and Water Hole. Samples taken from Wind Mill, Water Wall and Water Hole were characterized with high turbidity and color as well as high level of manganese, iron and nickel and elevated value of molybdenum. High level of iron was also found in Badger Spring, Willy Spring, and Paddock Well. These three water sources were also characterized with elevated values of fluoride and vanadium. Significant amounts of zinc were found in Water Wall and Water Hole samples. Water Wall sample was also characterized with high level of Cr VI . Compared to primary or secondary Navajo Nation Environmental Protection Agency (NNEPA) water quality standard the highest enrichment was found for turbidity (50.000 times), color (up to 1.796 times) and manganese (71 times), Cr VI (17.5 times), iron (7.4 times) and arsenic (5.2 times). Activities of 226 Ra and 238 U in water samples were still in agreement with the maximum contaminant levels. In order to comply with NNEPA water quality standard water samples were subjected to electrochemical treatment. This method was selected due to its high removal efficiency for heavy metals and uranium, lower settlement time, production of smaller volume of waste mud and higher stability of waste mud compared to physico-chemical treatment. Following the treatment, concentrations of heavy metals and activities of radionuclides in all samples were significantly lower compared to NNEPA or WHO regulated values. The maximum removal efficiencies for color, turbidity, arsenic, manganese, molybdenum and nickel were 100.0%. Maximum removal percentage of Cu, F − , V, Zn, 137 Cs, 226 Ra, 232 Th, 238 U were as follows: 98.0%; 82.7%; 99.9%; 95.6%; 75.0%; 76.9%; 80.0% and 99.2%. From the results presented it could be concluded that electrochemical treatment is a suitable approach for the purification of drinking water with complex mixture of contaminants, especially those with high turbidity and color.
Untreated drinking water is frequently overlooked as a source of antibiotic resistance in developed countries. To gain further insight on this topic, we isolated the indicator bacteria spp. from water samples collected in wells, fountains and natural springs supplying different communities across Portugal, and characterized their antibiotic resistance profile with both phenotypic and genetic approaches. We found various rates of resistance to seven antibiotic families. Over 50% of the isolates were resistant to at least ciprofloxacin, tetracyclines or quinupristin–dalfopristin and 57% were multidrug resistant to ≥ 3 antibiotics from different families. Multiple enterococcal species ( , , , and other spp) from different water samples harbored genes encoding resistance to tetracyclines, erythromycin or gentamicin [ (M)-46%, (L)-14%, (S)-5%, (B)-22%, -12%] and putative virulence factors [ -28%, 1-16%]. The present study positions untreated drinking water within the spectrum of ecological niches that may be reservoirs of or vehicles for antibiotic resistant enterococci/genes. These findings are worthy of attention as spread of antibiotic resistant enterococci to humans and animals through water ingestion cannot be dismissed. ►Non-treated human drinking water (NTHDW) has antibiotic resistant (AB ) enterococci. ►Several genes, (B), were dispersed in water samples. ►This is one of the few studies of AB enterococci from NTHDW of developed countries. ►This study adds NTHDW to the environmentally relevant reservoirs of resistant bacteria.
In recent history, human development overbalanced towards economic growth has often been accompanied by the degradation and reduction of freshwater resources at the expense of freshwater dependent ecosystems. For their subsistence and correct functioning, understanding environmental water requirements (EWR) represents an area of great interest for life cycle impact assessment (LCIA) and it has been only marginally explored. The aim of this paper is to investigate how this concept has evolved in ecological and hydrological literature and how it can be better integrated in LCIA, to identify potential options for improvement of LCIA indicators in the short, mid and long term.To address the limitations of existing LCIA approaches in modelling EWR, four families of EWR methods have been reviewed, namely hydrological, hydraulic, habitat simulation and holistic methods. Based on existing scientific literature and their broad application, 24 methods have been selected and their suitability to be adopted in LCIA has been evaluated against nine criteria, with regard to data management issues, accuracy, scientific robustness, and potential for future development. A semi-quantitative performance score has been subsequently assigned for each criterion, showing the main strengths and weaknesses of selected methods.The underlying rationale of the chosen approaches is markedly different, likewise the input information needed and results applicability. Hydrological methods are well suited for the development of global models and they are the only ones currently considered in LCIA, although their applicability remains limited to water stress indicators. Habitat modelling is identified as an essential step for the development of mechanistic LCIA models and endpoint indicators. In this respect, hydraulic, habitat simulation and holistic methods are fit for the purpose. However, habitat simulation methods represent the best compromise between scientific robustness and applicability in LCIA. For this reason, a conceptual framework for the development of habitat-based characterization factors has been proposed. Among the evaluated habitat simulation methods, ESTIMHAB showed the best performance and was the method retained for the development of an LCIA model that will assess the consequences of water consumption on stream ecosystems.This study identifies the advantages of specific modelling approaches for the assessment of water requirements for ecosystems. Selected methods could support the development of LCIA models at different levels. In the short-term for improving environmental relevance of water stress indicators, and in the mid/long-term to build up midpoint habitat indicators relating water needs of ecosystems with new endpoint metrics.