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.
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.
Isotopomer ratios of N2O (bulk nitrogen and oxygen isotope ratios, delta N-15(bulk) and delta O-18, and intramolecular N-15 site preference, SP) are useful parameters that characterize sources of this greenhouse gas and also provide insight into production and consumption mechanisms. We measured isotopomer ratios of N2O emitted from typical Japanese agricultural soils (Fluvisols and Andisols) planted with rice, wheat, soybean, and vegetables, and treated with synthetic (urea or ammonium) and organic (poultry manure) fertilizers. The results were analyzed using a previously reported isotopomeric N2O signature produced by nitrifying/denitrifying bacteria and a characteristic relationship between delta N-15(bulk) and SP during N2O reduction by denitrifying bacteria. Relative contributions from nitrification (hydroxylamine oxidation) and denitrification (nitrite reduction) to gross N2O production deduced from the analysis depended on soil type and fertilizer. The contribution from nitrification was relatively high (40%-70%) in Andisols amended with synthetic ammonium fertilizer, while denitrification was dominant (50%-90%) in the same soils amended with poultry manure during the period when N2O production occurred in the surface layer. This information on production processes is in accordance with that obtained from flux/concentration analysis of N2O and soil inorganic nitrogen. However, isotopomer analysis further revealed that partial reduction of N2O was pronounced in high-bulk density, alluvial soil (Fluvisol) compared to low-bulk density, volcanic ash soil (Andisol), and that the observed difference in N2O flux between normal and pelleted manure could have resulted from a similar mechanism with different rates of gross production and gross consumption. The isotopomeric analysis is based on data from pure culture bacteria and would be improved by further studies on in situ biological processes in soils including those by fungi. When flux/concentration-weighted average isotopomer ratios of N2O from various fertilized soils were examined, linear correlations were found between delta N-15(bulk) and delta O-18, and between SP and delta N-15(bulk). These relationships would be useful to parameterize isotopomer ratios of soil-emitted N2O for the modeling of the global N2O isotopomer budget. The results obtained in this study and those from previous firn/ice core studies confirm that the principal source of anthropogenic N2O is fertilized soils.
► Large energy monitoring and lifestyle campaign in the residential sector, in 12 EU countries. ► Information technologies and entertainment loads: key contributors to the power demand. ► Potential electricity savings up to 48% are possible in the European residential sector. ► Cold appliances, lighting and electronic loads are the main responsibles for the electricity savings. ► BAT associated with responsible consumer behaviour can reduce wasteful consumption. Although significant improvements in energy efficiency have been achieved in home appliances and lighting, the electricity consumption in the European Union household has increased by 2% per year during the past 10 years. Some reasons are associated with an increased degree of basic comfort and level of amenities and with the widespread utilisation of new types of loads. Wishing to increase the understanding of the energy consumption in the EU households for the different types of equipment including the consumers’ behaviour and comfort levels, and to identify demand trends, an energy monitoring campaign, was carried out in 12 geographically representative EU countries, accompanied by a lifestyle survey. From the measurements carried out it was concluded that Information Technologies and entertainment loads are key contributors to the power demand. In basically all types of loads there is wide range of performance levels in the models available in the market. Available technology, associated with responsible consumer behaviour, can reduce wasteful consumption. Based on a bottom up approach the European residential sector potential electricity savings that can be implemented by existing technologies and improved behaviour can reach 48%. The paper presents policy recommendations promoting market transformation and behavioural changes in the equipment selection and operation.
The watershed in the southern Jiangxi Province (Jiangxi Province is called simply Gan) (SGW) and the watershed in the central Guizhou Province (Guizhou Province is called simply Qian) (CQW) are two subtropical watersheds of the Yangtze River in China. Both watersheds have similar latitudes and climate, but distinct differences in basin lithology. These similarities and differences provide a good natural laboratory in which to investigate weathering processes and Sr end-members in river waters. This work aims to identify and contrast the sources, fluxes and controls on Sr isotopic composition in the river waters of these two areas. Results showed that the Sr-87/Sr-86 in the SGW waters ranged from 0.716501 to 0.724931, with dissolved Sr averaging 27 mu g l(-1). Rhyolites and granites are two major sources for the dissolved Sr. The SGW waters receive 42% of their Sr from silicates weathering, 32% from carbonates and 3.2% from evaporites. Sr-87/Sr-86 in the CQW waters has a lesser variation from 0.707694 to 0.710039, but higher Sr contents (average of 208 mu g l(-1)). Dolomite, limestone and dolomitic limestone are major sources of Sr in the waters. The CQW waters receive 69% of their Sr from carbonates, 1.7% from silicates and 0.9% from evaporites. The chemical erosion rate and Sr flux in the CQW are 122 t km(-2)a(-1) and 0.079 t km(-2)a(-1), respectively, which are higher than those of the SGW (56 t km(-2)a(-1) and 0.021 t km(-2)a(-1), respectively). These data suggest that the intensive carbonates weathering occurred in the karstic area in the upper-reach of the Yangtze River exert great influence on the high Sr concentration and low Sr isotopic ratios in the River. (C) 2011 Elsevier B.V. All rights reserved.
Maintenance, cell death and predation are endogenous processes of microorganisms and play an important role in governing the overall performance of biological wastewater treatment systems. However, in the previous studies on the activated sludge system, a widely used biological wastewater treatment process, the endogenous processes are summarized as a single process and the kinetics of all related processes are lumped into a single parameter set. In order to better understand the endogenous processes, efforts are made to quantify the maintenance, cell death and predation processes separately with both experimental and mathematical approaches in this work. A model-based analysis on endogenous processes of activated sludge is performed. Both oxygen uptake and biomass concentration gradually decrease with the increasing length of aerobic starvation. Model predictions are in accordance with experimental data. The active bacteria content is reduced to about 23% of the initial value after 10-day starvation, and the maintenance energy consumption rate under non-growth conditions is found to be about four times of that when the microbial growth is of its maximum level. The active microorganisms form the prey for the predator growth. The oxygen consumption related to the predation of active bacteria significantly contributes to the total oxygen consumption.
Galaxias maculatus is an osmeriform native fish of the Southern Hemisphere, in which the crystalline larvae is considered as a luxury delicacy, for this reason, it has been commercially exploited in Chile, Argentina and New Zealand. However, the fisheries have been rapidly decreasing due to the overexploitation and the predation of introduced species. Because of these events, there is a need to determine a carrying capacity for an intensive fish culture. In order to optimize stocking densities for fish culture, this paper proposes objectives to determine oxygen consumption (OC) rates, dissolved oxygen concentrations that produce signs of hypoxia and the average time elapsed between food intake and peak OC in G. maculatus . In the oxygen experiments under routine metabolism conditions, we found that G. maculatus adults and whitebait showed signs of asphyxia at dissolved oxygen concentrations between 1.3 and 2.2 mg L −1 and that adults tolerated dissolved oxygen levels as low as 1.3 mg L −1 . The results showed that G. maculatus individuals with an average weight of 0.04 g consumed 0.048 mg O 2 h −1 , whereas individuals with an average weight of 1.4 g consumed 0.345 mg O 2 h −1 . Galaxias maculatus increased the OC rate by 31%, from 0.39 to 0.51 mg O 2 h −1 g −1 , occurring 14 min after food intake. The carrying capacities for industrial cultures of G. maculatus , were estimated using an allometric equation (OC=0.2363 × W 0.612 ), a water flow rate of 1 m 3 h −1 and an input oxygen concentration of 10 mg L −1 at 12 °C. The density culture of whitebait (4 g) can be allowed to reach 8–11 kg m −3 ; therefore, these stocking densities reduce the risk of hypoxia and mortality, ensuring the appropriate growth and feed conversion rates.
▶ Systematic methodology to define and evaluate a process for a subsequent in-depth energy analysis. ▶ Definition and characterization of a base case in a water and energy oriented perspective. ▶ Procedure: data gathering, master diagram construction, utilities systems analysis, simulation. ▶ Simulation model developed to obtain detailed information of the steam and water systems. ▶ Process inefficiencies are identified such as condensate recovery or non-isothermal mixing. The development of a base-case process is a fundamental step in an energy efficiency study to obtain reliable results. However, this step is often overlooked and there are no clear guidelines for the systematic development of the base-case. A methodology has been proposed to properly define and evaluate the complete process for a subsequent in-depth energy analysis. It consists of two stages: definition and characterization of the process, and benchmarking analysis. In this paper, the first stage is presented. The base-case should encompass the process and the utilities systems, i.e., steam and water, as they are the driving forces of the chemical transformations. A four-pronged procedure is proposed to properly define and characterize a process and its utilities: data gathering, master diagram construction, utilities systems analysis, and simulation. The main objective is to build a computer simulation model to provide detailed information on production, distribution, utilization and post-utilization treatment of steam and water. Process inefficiencies are also identified, such as the low condensate recovery or the presence of non-isothermal mixing points. The procedure has been applied to an operating Kraft pulping mill in Eastern Canada.