Specific Water Consumption Research Articles

DYNAMICS OF WATER CONSUMPTION CHANGES IN A TOURIST RESORT

This work presents problems related to the water consumption in the city of Olecko situated in the north-east part of Poland in the Warminsko-Mazurskie Province of the country, at the eastern border of the Mazurian Lake District along the trail connecting the land of the Large Mazurian Lakes with the Suwalsko-Augustowskie Lake District. Over 2011–2012 water extraction to the municipal water supply network was studied. The volume of water extracted every day was analyzed and the gathered volumes were analyzed statistically. The varying water extraction was also studied. The obtained results were presented in a graphic form. Basing on the descriptive stats and prepared diagrams certain general conclusions were drawn and the collected study figures and facts were summed up. This allowed to determine days of the highest and lowest water consumption. Also months of extreme water extraction and consumption were determined. The water extraction ranged from 1641 m 3 /24h to 2607 m 3 /24h, at an average value of 2077.4 m 3 /24h. Over the period under study the day of the largest water extraction and consumption was in July and the day of the lowest water extraction and consumption in December. During a week inhabitants used the highest water amount on Saturdays and the lowest on Sundays and other feast-days. Basing on the conducted measurements also the coefficient of water consumption per capita was determined. The fluctuation of this coefficient was identical as that for the water consumption. Within the period of study it ranged from 73.3 l/M 24h to 116.5 l/M 24h. The average value of the specific water consumption was 92.8 l/M 24h. For the sake of discussion the obtained results were compared with observations across the country.

Hydrogen energy share improvement along with NOx (oxides of nitrogen) emission reduction in a hydrogen dual-fuel compression ignition engine using water injection

Abstract The study aims at enhancement of Hydrogen (H 2 ) energy share and reduction of Oxides of Nitrogen (NO x ) emission in a 7.4 kW-CI engine at 1500 rpm using water injection. The test engine was modified to run under dual-fuel operation with diesel–biodiesel blend (B20) and H 2 fuels for different Specific Water Consumption (SWC) of 130, 200, and 270 g/kWh. Under conventional H 2 dual-fuel mode, energy efficiency and NO x emission increased significantly while Hydrocarbon (HC), Carbon Monoxide (CO) and smoke emissions decreased. The maximum H 2 energy share increased from 20% without water to 32%, 36%, and 39% with SWC of 130, 200, and 270 g/kWh respectively. However, SWC of 200 g/kWh was selected as an optimum water quantity for knock free operation, better performance and lower emissions. At the optimum SWC with 20% H 2 energy share, the NO x emission and energy efficiency decreased about 24% and 5.7%, while HC and smoke emissions increased about 38% and 69%. At 20% H 2 energy share, the CO emission increased from 0.0 g/kWh without water to 1.2 g/kWh with the optimum SWC. However, reduction of these HC and CO emissions using oxidation catalysts needs to be studied further. A new methodology for determining heat release rate with consideration of crevice gas was proposed in the study.

Energy Efficiency in Greenhouse Evaporative Cooling Techniques: Cooling Boxes versus Cellulose Pads

Evaporative cooling systems using a combination of evaporative pads and extractor fans require greenhouses to be hermetic. The greatest concentration of greenhouses in the world is located in southeast Spain, but these tend not to be hermetic structures and consequently can only rely on fogging systems as evaporative cooling techniques. Evaporative cooling boxes provide an alternative to such systems. Using a low-speed wind tunnel, the present work has compared the performance of this system with four pads of differing geometry and thickness manufactured by two different companies. The results obtained show that the plastic packing in the cooling unit produces a pressure drop of 11.05 Pa at 2 m·s−1, which is between 51.27% and 94.87% lower than that produced by the cellulose pads. This pressure drop was not influenced by increases in the water flow. The evaporative cooling boxes presented greater saturation efficiency at the same flow, namely 82.63%, as opposed to an average figure of 65% for the cellulose pads; and also had a lower specific consumption of water, at around 3.05 L·h−1·m−2·°C−1. Consequently, we conclude that evaporative cooling boxes are a good option for cooling non-hermetic greenhouses such as those most frequently used in the Mediterranean basin.

Estimation of the Water Temperature Influence on Direct Evaporative Cooler Operation

In the present paper a study is conducted of the mass and heat transfer phenomena which rule the function of a direct evaporative cooler. A comprehensive mathematical model is developed, which is based on the latent and sensible heat transfer and can predict the effectiveness of such a cooler under any circumstances of operation and water supply. As a development of the existing simulation models of direct evaporative coolers, the model presented here is general, as far as the temperature of the supply water is concerned. In addition, direct evaporative cooling is valued according to its efficiency, the quality of outcoming air and the specific consumption of water while working in Mediterranean climates.

University campuses energy performance estimation in Ukraine based on measurable approach

Abstract Aim of research is an attempt to create the methodology for University campuses (UC) energy certification system for Ukraine. Therefore, taking into account national conditions, the certification variant, based on the instrumental approach to the UC data as a whole, has been suggested and analyzed. Normalized information on energy consumption has been analyzed based on weather and climatic conditions and operating parameters of UCs and used for UCs clustering based on the Universities’ activity profiles and their specific energy consumption. There was a research conducted of three variants of energy efficiency grading for UCs of Ukraine according to end-use specific heat consumption, electricity consumption, total energy consumption and specific water consumption. The paper demonstrates possibilities and problems of using certification to determine the UCs energy consumption efficiency. The offered approach allows to determine the University campuses energy performance in general and using certification to compare UCs energy efficiency.

Water quantity auditing of a Ghanaian beverage plant

The study aimed at conducting a water quantity audit in a Ghanaian beverage plant. Primary data on the daily volumes of input water from the main reservoirs of the plant, daily volumes of beverage produced and the water consumed at the 8 metered stages of the plant out of a total of 12 stages were recorded over a period of four months. Secondary data on the plant's monthly water consumption was obtained from Ghana Water Company Limited billing records for the period January 2005 to December 2009. The study revealed that, the average monthly water consumption was 9,825 m3 with a standard deviation of (±1,399) in the past five years (2005–2009). Stages with high water usage in the plant were the Syrup and Beverage Preparation stage (55%) and the Bottle Washer Equipment stage (34%). Furthermore, the plant's specific water consumption determined was 3.5 : 1 which is better than the company's target of 4 : 1. This indicates that the plant's current water use efficiency is good and therefore encouraging.

Assessment of the consumption of water and construction materials in state-of-the-art fossil fuel power generation technologies involving CO2 capture

There is a growing concern about the impact of energy system decarbonisation on natural resources, such as raw materials and freshwater. Along this line, this paper assesses the needs for cooling water and construction materials of pulverised coal combustion (PF), integrated gasification combined cycle (IGCC) and natural gas combined cycle (NGCC) power generation technologies with and without CCS (Carbon capture and storage). Moreover, the paper evaluates how the integration of CCS technologies influences the economics and operational performance of power plants providing up-dated techno-economic indicators. Introduction of CO2 capture results in an increase of specific water consumption compared to a conventional plant which is more significant in the cases of PF and NGCC (56–62% and 50%) than in IGCC (9–12%). Therefore, the large scale deployment of CCS can have a significant impact on freshwater resources. The introduction of CO2 capture also increases significantly the amount of plant construction materials. The increase is up to 100% for concrete and steel and up to 27% for copper and polyethylene. The cost of construction materials is 8–15% of total investment costs, hence any changes in their prices can have a measurable impact on the cost of a plant and hence on the competitiveness of the underlying technology.

Rationalizing the Use of Water in Industry—Part 1: Summary of the Instruments Developed by the Clean Technology Network in the State of Bahia and Main Results Obtained

Based on cleaner production concepts, a method for water use minimization has been developed by the Clean Technology Network of Bahia (TECLIM) at one of the largest industrial complexes in Latin America located in the State of Bahia, Brazil. This method is concerned with an area of secondary interest to the productive sector: the use of water. Based on the best cleaner production principles (CP), nine instruments have been developed during cooperative projects with chemical, petrochemical and copper metallurgical industries. These instruments are described in Part 2 of this paper [1]. The main benefits derived from partnership schemes include: a reduction in water consumption and effluent generation; the development of a techno-operational culture to increase eco-efficiency; and the introduction of conceptual projects to ensure the continuity of the activities in the company after the projects have been completed. The specific consumption of water was reduced by 20% as a consequence of the application of this method in Company A; a specific reduction in the generation of effluents of more than 40% was observed in Company B; a 42% fall in fresh water consumption in Company C; and a 20% decrease in the cost of effluent treatment in Company D. Among the difficulties encountered were the limited time availability of the operators and engineers for the project, the lack of measurement and calibration of available flow meters and the lack of detailed technical data.

The anaerobic MBR for sustainable industrial wastewater management

Anaerobic high rate processes are considered cost and resource efficient solutions for treating wastes and wastewaters. Referring to the global current “energy discussion,” anaerobic conversion processes recover “organic waste enclosed energy” to the gaseous energy carrier CH4, whereas no energy is required for stabilizing the waste organic matter. Considering the ongoing trends in industries to reduce specific water consumption, and thereby drastically changing the process water characteristics, membrane bioreactor (MBR) application opportunities are expected to grow in the future. Compared to aerobic MBR technologies, anaerobic MBR (AnMBR) systems do have the same energy benefits as all other anaerobic systems with regard to treatment of organic pollutants, but do also create an absolute barrier for the biomass. By using ultrafiltration membranes, both the dissolved and nondissolved organic matter are retained in the bioreactor preventing that they will leach out with the effluent or digestate. This makes further degradation and transformation of organic matter into biogas possible, and provides very clear and reusable water. These combined benefits provide an attractive economic and ecological perspective to treat industrial aqueous waste streams. Operating an AnMBR pilot plant for the wastewater from a salads factory has shown that the side stream (gaslift) anaerobic MBR system can operate stable at a significant higher flux levels (around 20 l/m2-h) than the submerged AnMBR. Moreover, due to the absolute barrier to biomass, more organic material is converted to biogas (conversion rates up to 90% are achieved) compared to the conventional Upflow Anaerobic Sludge Bed systems (typically around 70% conversions). The effluent is clean and free of suspended solids allowing easy reuse of water or the discharge costs will be lower.

Development and testing of a water-efficient laundry system in informal settlements of eThekwini municipality, South Africa

In the informal settlements of eThekwini municipality, South Africa, laundry activities are typically undertaken at local standpipes and washbasins of community ablution blocks (CABs), and are characterised by high levels of water consumption and greywater production. Since greywater contains a high pollution load, including sodium tripolyphosphate, it poses a significant environmental and public health risk. The overall objective of this study was to develop and test a water-efficient laundry system designed for informal settlements. Initial fieldwork at a standpipe and CAB in eThekwini municipality showed respectively 56 and 58% of users were in favour of a water-efficient laundry system based upon sharing washing water. Subsequent laboratory work assessed crosscurrent and countercurrent cascades for washing clothes. Under optimised washing conditions at a detergent dose of 5 g/kg water, specific water consumption of 5 kg water/kg clothes and three rinsing phases it was determined that the countercurrent method wasted 33% less water. Thus the countercurrent cascade has great potential for minimising greywater production in South African informal settlements. Future work should concentrate on evaluating greywater production, detergent usage and social acceptability in the field.

The water footprint of soy milk and soy burger and equivalent animal products

As all human water use is ultimately linked to final consumption, it is interesting to know the specific water consumption and pollution behind various consumer goods, particularly for goods that are water-intensive, such as foodstuffs. The objective of this study is to quantify the water footprints of soy milk and soy burger and compare them with the water footprints of equivalent animal products (cow's milk and beef burger). The study focuses on the assessment of the water footprint of soy milk produced in a specific factory in Belgium and soy burger produced in another factory in the Netherlands. The ingredients used in the products are same as real products and taken from real case studies. We analysed organic and non-organic soybean farms in three different countries from where the soybeans are imported (Canada, China, and France). Organic production reduces soil evaporation and diminishes the grey water footprint, ultimately reducing the total water footprint. The water footprint of 1l soy milk is 297l, of which 99.7% refers to the supply chain. The water footprint of a 150g soy burger is 158l, of which 99.9% refers to the supply chain. Although most companies focus on just their own operational performance, this study shows that it is important to consider the complete supply chain. The major part of the total water footprint stems from ingredients that are based on agricultural products. In the case of soy milk, 62% of the total water footprint is due to the soybean content in the product; in the case of soy burger, this is 74%. Thus, a detailed assessment of soybean cultivation is essential to understand the claim that each product makes on freshwater resources. This study shows that shifting from non-organic to organic farming can reduce the grey water footprint related to soybean cultivation by 98%. Cow's milk and beef burger have much larger water footprints than their soy equivalents. The global average water footprint of a 150g beef burger is 2350l and the water footprint of 1l of cow's milk is 1050l.

Wind tunnel analysis of artificial substrates used in active living walls for indoor environment conditioning in Mediterranean buildings

In this paper, a low-speed wind tunnel was used for experimental analysis of water volume retained, pressure drop, saturation efficiency and water consumption for three types of synthetic substrates used in active living walls: polyester (PR), polyurethane (PU) and polyamide–polypropylene (PA–PP) The substrates were of a similar thickness and were tested for different water and air flows. The water retained increases with higher water flow. The pressure drop increases with the presence of vegetation and when air speed and water flow is higher. Cooling efficiency is enhanced with vegetation and low air speed. Specific consumption of water is greater with vegetation at higher air speeds. Therefore, low air (between 0.25 and 0.5 m s−1) and water flows are recommended to ensure a homogeneous wetting of the substrate surface. PA–PP has the greatest pressure drop of the three, but also presents the best saturation efficiency, with an average water retention capacity and less specific consumption. PU offers the least resistance to air flow, with an intermediate efficiency level and high water consumption and water retention capacity. PR presents the worst saturation efficiency, a medium level of pressure drop and high water consumption.

Environmental Impacts of Water Use in Global Crop Production: Hotspots and Trade-Offs with Land Use

Global crop production is causing pressure on water and land resources in many places. In addition to local resource management, the related environmental impacts of commodities traded along international supply chains need to be considered and managed accordingly. For this purpose, we calculate the specific water consumption and land use for the production of 160 crops and crop groups, covering most harvested mass on global cropland. We quantify indicators for land and water scarcity with high geospatial resolution. This facilitates spatially explicit crop-specific resource management and regionalized life cycle assessment of processed products. The vast cultivation of irrigated wheat, rice, cotton, maize, and sugar cane, which are major sources of food, bioenergy, and fiber, drives worldwide water scarcity. According to globally averaged production, substituting biofuel for crude oil would have a lower impact on water resources than substituting cotton for polyester. For some crops, water scarcity impacts are inversely related to land resource stress, illustrating that water consumption is often at odds with land use. On global average, maize performs better than rice and wheat in the combined land/water assessment. High spatial variability of water and land use related impacts underlines the importance of appropriate site selection for agricultural activities.

Changes in water dependence of Russian economy

Indicators of source water use in different economic branches, water consumption in recycling and recycling-successive water supply in 1980–2006 are analyzed. Trends were identified in variations in specific water consumption in industry, agriculture, and municipal economy. Territorial differentiation of wetness indicators of regional product over federal districts and constituent territories of the RF is shown. Wetness values of gross domestic product in different economies are compared.

Wet electrostatic scrubbers for the abatement of submicronic particulate

Water electrostatic scrubber (WES) represents an alternative technology for the abatement of that submicronic fraction of particulate – belonging to the so-called Greenfield gap – usually hardly captured with other cleaning techniques. The promising potentialities of WES are recognized by the scientific and industrial communities, but the design of this kind of reactor is far from being optimized. This work reports a mathematical model to evaluate the particle removal efficiency in wet electrostatic scrubbers. The model is used to find out optimal working condition of WES units, through the maximization of the particle collection efficiency in function of different process parameters: contact time, specific water consumption, water/gas relative velocity, size and charge of sprayed droplets. The model has been validated by comparison with different experimental data available in literature, both for charged and uncharged scrubbers. Then it is applied to a reference case study to obtain generalizable results. The model shows that the process optimization for micronic and submicronic size particles follows different criteria. For micronic particles, the collection efficiency increases for higher water/gas relative velocity, with a small effect of droplet diameter and a moderate increase with the droplet charge. On the contrary, in the Greenfield gap, the water/gas velocity plays a secondary role in the capture mechanisms, while a substantial increase of collection efficiency by improving the droplet charge level and reducing the droplet size has been observed. With reference to the actual performances of water spraying and charging devices, the model predicts that a collection efficiency as high as 99.5% can be reliably obtained in few seconds with a water consumption of 100 ml/m 3 by adopting droplet diameters around 100 μm and charge to mass ratio from 1 to 3 mC/kg, corresponding to droplet charge equal to 10–30% of Rayleigh limit.

Sequential quadratic programming and analytic hierarchy process for nonlinear multiobjective optimization of a hydropower network

AbstractIn this paper, an optimal annual scheduling for power generation (i.e. rule curves and volume of water releases) in serial or parallel hydropower plants is developed. Multiobjective programming and weighted sum method are used to convert a multiobjective problem to a single objective one. Furthermore, to obtain viable alternatives under existing uncertainty, some random weight vectors in the whole weighting space are generated and for each weight vector an optimal solution is found using sequential quadratic programming (SQP). Then, analytic hierarchy process (AHP) is used to select the best solution according to a given criterion, and determine the most preferred one. Besides, this method does not require choosing a priori preference for the objective function, thus making an ideal tool for handling complicated multiobjective models and easy to use with the aid of computer programs. Combination of multiobjective optimization and multicriteria decision analysis (MCDA) is an integrated methodology that is capable of dealing with complex water management problems. Various scenarios for dry, median, and wet years are assumed based on stochastic flows from external sources (e.g. flooding rivers, unexpected rains, etc.) coming into each reservoir, and turbine power generation is obtained from hill diagrams provided by the manufacturer. The application of this methodology is illustrated in a case study for optimal scheduling of Karoon River Basin, where the decision support system and optimization routines are implemented in MATLAB. The total energy productions for 10 optimized solutions under dry, median, and wet scenarios (generated from forty‐year historical inflow records) are calculated, and specific water consumption for each reservoir is obtained in different months. This can significantly help decision makers to have an optimal and more intelligent management over energy productions in hydropower plants and associated thermal power plants. Copyright © 2009 John Wiley & Sons, Ltd.

Studies on the performance of a rotating drum bioreactor for bioleaching processes — Oxygen transfer, solids distribution and power consumption

Rotating drum bioreactors have shown the potential for bioleaching processes with high solids concentration. A gas-sparger that can produce small bubbles (∼ 1.0 mm) has been fitted into a rotating drum bioreactor to improve gas–liquid mass transfer performance. Gas–liquid mass transfer, solids distribution and power consumption in the rotating drum bioreactor were evaluated as function of bioreactor operating parameters. k L a of the evaluated rotating drum bioreactor varied in the range between 0.0326 s − 1 and 0.0927 s − 1 with aeration rate varying from 0.286 vvm to 1.43 vvm and rotational speed from 1.67 rpm to 10.0 rpm, which was close to that of typical stirred tank bioreactors. A relative uniform solids distribution was achieved at the rotational speed 3.33 rpm and the aeration rate 0.429 vvm. The specific power consumption of tap water and slurry were 0.0186 W/L (11.0 rpm, without particles) and 0.0407 W/L (11.0 rpm, solids volume fraction 0.097) respectively, and this indicated that the rotating drum bioreactor could provide microbes in a slurry with low particle collision effect. The tested rotating drum bioreactor possessed excellent gas–liquid mass transfer performance and low power consumption, making it suitable for gas–liquid–solid-microbes reaction systems, such as bioleaching processes.

Adoption of European Union's IPPC Directive to a textile mill: Analysis of water and energy consumption

The present study was undertaken as part of the first application and evaluation of the BREF (Best Available Techniques; BAT Reference Document) Textile Document within the context of the European Union's Integrated Pollution Prevention and Control (IPPC) Directive to a large scale textile mill in Turkey. The BAT requirements for the denim manufacturing textile mill were selected in cooperation with the factory management. Detailed mass balance calculations were conducted to evaluate the overall effect of the selected BAT options. The initial findings indicated that the adoption of the selected BAT options resulted in considerable savings in water and energy consumption in the mill. Besides the installation of flow meters and use of semi-counter current rinsing in the most water-intensive processes, minimization of wash waters in the water softening plant, reuse of the concentrate stream from the reverse osmosis plant and compressor cooling waters provided a 29.5% reduction in the total specific water consumption of the mill, reaching the lower limits suggested by the BREF Textile Document. In terms of energy consumption, use of waste heat from finishing wastewater streams in heating up the wash waters, heat insulation and maintenance applications in addition to BAT measures taken for water minimization reduced specific energy consumption by 9% achieving the limits set by the BREF Textile Document.

Developing the technology for the effective final concentration of gold-containing gravity concentrates

Jigging technology in a closed cycle is tested and optimized at one department of industrial gold mining for the final concentration of gravity concentrates with the use of PGShOK-50-2 sprinkling installation. The equation of regression—which adequately describes the dependence of the Goden selectivity index on the travel and vibration frequency of the cones, the specific consumption of the undersize water, and the height of the artificial bed during the operation of the jigging machine in such a mode—is obtained. It is established that, as the Au content in the starting product increases, which is promoted by the closed jigging cycle, its extraction into the concentrate (ɛ) also increases. As the operation of the concentration table is optimized, the influence of the frequency and travel length of the saddle, as well as of the angle of its transverse inclination, is investigated. The tailings of all apparatuses, which are used for the final concentration of gravity concentrates, are repurified by column flotation prior to output into the pile. The kinetics for gold grains of different fineness is investigated. As a result of optimizing the operation of a MOD-0.2 jigging machine and the SKO-0.5 concentration table, the extraction of metal from the crude concentrate into a product corresponding to requirements of refining (>92% of gold bullion) increased by 1.4–1.7% and was ≥98%. An increase in the productivity of the jigging machine, due to the use of jigging technology in a closed cycle and the stable operation of the concentration table, provided an increase in the productivity of the final concentration department of the gold-concentration installation on the whole.

Chemical characterisation of extract derived from Daphne papyraceae and sonicator dyeing of cotton, silk and wool with the extract

PurposeThe purpose of this paper is to evaluate the efficiency of ultrasonication on new natural dye obtained from leaves and stem extracts of Daphne papyraceae using metal mordant for good cotton, silk and wool dyeing prospects. It also proposes to effect the characterisation of the colorant.Design/methodology/approachFor effective natural dyeing with leaves and stem extracts of D. papyraceae, both conventional and sonication methods for cotton, silk and wool dyeing were carried out using metal mordants. The purpose of using sonication was for betterment of dye uptake, improved dye adherence and good wash and light fastnesses. Results show marked improvement by the chosen dyeing method. Simultaneously, chemical characterisation of the colorant was carried out by first column chromatographic separation of the crude extract, followed by spectral analysis of the isolated products.FindingsThe superiority of sonicator dyeing over conventional dyeing in terms of enhanced resource productivity and, as a result, reduced wastes makes it the established best available technique in the natural dyeing industry. This fact has been examined for several natural dyes. Use of sonicator shows marked enhancement for cotton‐, silk‐ and wool‐dyed fabrics. Typical bath liquor to fabric ratio for conventional dyeing varies from 20:1 to 15:1 and for sonicator dyeing from only 12:1 to 10:1, thereby reducing specific water and energy consumption by 30 and 50 per cent, respectively. The cycle time for dyeing was also reduced by 50 per cent and this would benefit the dyeing process with more tonnage of fabric per unit time and with lower waste generation. This would also result in improved capacity utilization leading to enhanced productivity levels in the dyeing houses.Research limitations/implicationsAlthough metal mordanting with copper sulphate and potassium dichromate is not ecofriendly, only 2 per cent of these metal salts has been used to prepare different shades with leaves and stem extracts of D. papyraceae for cotton, silk and wool fabrics.Practical implicationsThe method developed for natural dyeing of cotton, silk and wool fabrics using sonication in conjunction with metal mordanting has shown marked improvement. The chemical composition of the crude extract shows the presence of flavonoids and other specific natural pigments.Originality/valueThe method developed for natural dyeing of cotton, silk and wool fabrics using stem and leaves extracts of D. papyraceae under sonication in conjunction with metal mordanting has shown marked improvement in terms of dye adherence and fastness properties and can thus be recommended for industrial application. This is a new source of natural dye.