Minimum Water Consumption Research Articles

FORECASTING OF THE EXTREME WINTER LOW FLOW FOR THE NORILKA RIVER

The object of the study is the Norilka River, located in the North of the Krasnoyarsk territory. Only 45% of the norm of precipitation fell in the basin of the Norilka River for the period from October 2012 to May 2013, that resulting in an extremely low spring flood formation. The feeding of the large lakes that form the river flow was also limited, as dry weather set in during the summer. This caused great concern regarding the water availability of water intakes of mining and processing plant in the city of Norilsk for the winter of 2014. The situation required the solution of a complex of hydrological tasks, the main of which is the development of a forecast of minimum water consumption for the winter of 2014. The forecast was developed using relationship between area pre-winter moistening with intensity of the winter runoff depletion. Since the capacity of the ice cover can significantly affect to decrease of the river flow, the hydrological forecast takes into account the long-term air temperatures forecast for 2013-2014 winter period. It was obtained the forecast that the minimum monthly discharge for April would be at about 22 m3/s, meanwhile daily discharge 20 m3/s. The received results were a basis for carrying out the measures directed on maintenance of steady water supply with need discharge in 7 m3/s. The low ground dam below water intakes was arranged at backwater on a site of water intakes for August-September 2013. The actual flow discharge for April 2014 was about 14 m3/s. Therefore, the construction of the dam was justified and interruptions of water supply of the plant did not happen. The methodological approaches applied to the solution of this problem can be useful in case of similar situations in the Northern regions of Russia.

Minimizing beneficiation wastewater through internal reuse of process water in flotation circuit

Cost-effective methods for reducing freshwater requirement and wastewater emission in beneficiation processes (particularly in flotation process) are greatly important in the modern mining industry. This study aims to minimize water consumption and wastewater generation in dressing plants by internally reusing process water at certain stages of flotation circuit . Laboratory scale tests demonstrated that locked cycle recycling of process water built up chemical reagents in water, which in turn influenced the flotation performance of valuable minerals and significantly decreased the grade and recovery of concentrates. Changing flotation reagent regimes in response to flotation fluctuations can reliably and feasibly maintain mineral recovery efficiency during the reuse process. Industrial scale tests validated that the quality of concentrates obtained with and without process water reuse did not show any considerable difference and satisfied the product specifications by carefully adjusting the dosage of flotation reagent. The required reagent dosages in the flotation circuit were reduced by more than 10% after using recycled water. Among the required reagent dosages, sodium sulfide (Na 2 S) was sharply reduced by 18.56%. Most importantly, the internal reuse of process water in the flotation circuit minimized freshwater consumption by 34.62% (i.e., from 5.2 t/d to 3.4 t/d), indicating that 525.6 tons of wastewater would no longer be generated every year. Overall, the proposed internal reuse process is a cost-effective and eco-friendly alternative for greening flotation process. • Internal reuse of process water in the flotation process is feasible and reliable. • Changing reagent suite reduces the negative effect of process water on flotation. • Internal reuse of process water minimized water consumed and wastewater emission. • Internal reuse of process water promotes the reutilization of chemical reagents.

Pinch Methods for Efficient Use of Water in Food Industry: A Survey Review

The implementation of sustainable water management practices, through the recycling and reuse of water, is essential in terms of minimizing production costs and the environmental impact of the food industry. This problem goes beyond the classical audit and housekeeping practices through developing a systemic water-using reduction strategy. The implementation of such an approach needs R&D development, especially for the food industry, where there is a lack of knowledge on: (a) process integration and (b) data on the pollutant indicators or (c) volumes of water used and discharged at specific steps of the food processing line. Since energy pinch analysis emerged, different variations of pinch methods have been developed. As a variation of pinch, Water pinch analysis is a global and systematic approach to minimize water consumption and discharges, especially for the most energy-intensive and water-consuming factories. Based on the nature of the food industry, the real systems are complex, multi-source multi-contaminant systems, the problem should be well formulated, including mathematical constraints (inequalities thresholds). Current work has reviewed comprehensive literature about different variations of pinch analysis. In continue, water pinch method deeply discussed and some relevant data concerning the water using process and pollutant indicators have been reviewed with emphasis on the food industry sector.

Experimental studies of furfural production from water hyacinth (Eichhornia Crassipes)

AbstractFurfural is a very promising product of lignocellulosic biomass‐based biorefineries and has the potential to become a useful resource for further conversion and utilization. Aquatic plants show an enormous potential as feedstock since they do not compete for land use, and they require minimal water consumption in a biorefinery concept due to their very high water content. This work is focused on experimental studies of furfural production from water hyacinth (Eichhornia crassipes) by means of aqueous, acid‐catalyzed dehydration. The temperature range of the process, and the acid and seawater presence were chosen based on the previous relevant studies. The aim of the study was to determine whether water hyacinth is suitable for furfural production. The experiments were performed between 160°C and 200°C with a water hyacinth concentration of 2 wt%. The results suggest that the effects of acid catalyst presence on biomass dehydration are similar to the case of pure pentose dehydration. Furthermore, the addition of seawater did not have a positive catalytic effect in terms of the furfural yield. The maximum yield was 53.2 mol% based on the C5 sugar content in the original biomass. The furfural yield of 7.9 wt% of water hyacinth input was comparable to the yield of feedstocks such as corn cob, bagasse, and oat's residue and higher than the cases of rice straw or hulls. Thanks to the comparatively high pentose potential, water hyacinth shows promising results as a candidate feedstock for furfural production. A certain variability of pentosan should be taken into account, as the chemical composition of the plant depends on the source and harvesting seasons.

Process Integration and Feedstock Optimisation of a Two-Step Biodiesel Production Process from Jatropha Curcas Using Aspen Plus

Abstract Jatropha curcas oil (JCO) has been recognized as a viable non-edible feedstock for biodiesel production with the focus of achieving lesser reliance on fossil fuels. The aim of this work is to integrate and simulate the production of biodiesel from Jatropha curcas oil by a two-step process; a hydrolysis step and a trans-esterification step. The challenge is then to optimise the feedstock ratios to obtain the minimal water and methanol consumption to give optimal biodiesel yield. For this purpose, steady-state simulation model of a two-step production process of biodiesel from Jatropha curcas oil was prepared using ASPEN Plus V8.8. The response surface methodology (RSM) based on a central composite design (CCD) was used to design optimisation experiments for the research work. From the ANOVA, methanol/oil ratio of the trans-esterification step was found to have a significant effect on the biodiesel yield compared to the water/oil ratio of the hydrolysis step. The linear model developed was shown to be a good predictor of feedstock ratios for biodiesel yield. The surface plot revealed that both feedstock ratios do not show a significant combinatorial effect on each other. Numerical optimisation gave the optimum values of the feedstock ratios as a methanol/oil ratio of 2.667 and a water/oil ratio of 1. The optimisation results also indicated a predicted optimum biodiesel yield of 10.0938 kg/hr.

Modified genetic algorithm with simulated annealing applied to optimal load dispatch of the Three Gorges Hydropower Plant in China

ABSTRACTA method is presented for optimal load dispatch in large-scale hydropower plants using a genetic algorithm integrated with simulated annealing. The genetic algorithm overcomes dependence on an initial value and provides parallel processing and fast convergence, whereas simulated annealing prevents prematurity and retrieving of the local instead of the global optimum. Thus, the integrated genetic-simulated annealing algorithm improves efficiency and robustness to obtain solutions close to the global optimum. We evaluated the proposed algorithm to determine the optimal load dispatch of 32 units of the Three Gorges Hydropower Plant in China. Test results show that the minimum water consumption obtained using the proposed algorithm is similar to the optimum obtained from a previously proposed “improved” genetic algorithm when the total load of the plant is relatively high. However, for reduced load, the proposed algorithm clearly outperforms the “improved” genetic algorithm.

A novel green approach for dyeing polyester using glycerine based eutectic solvent as a dyeing medium

In the past decade, water scarcity has become major concern and is going to be reality in future too. At the same time textile is necessity which needs a billion liters of fresh water for its processing. Out of this 16 % of water is only used for dyeing of textile materials. In a quest to develop a sustainable approach to reduce water scarcity, an attempt has been made to minimize water consumption in textile wet processing. In this work, an eco-friendly glycerine based eutectic solvent (GES) was prepared by using choline chloride, urea and glycerin to reduce water consumption in polyester dyeing. The prepared solvent was characterized in terms of FTIR. Dyeing parameters like time, temperature and pH were optimized for dyeing of polyester using GES as a dyeing medium. The efficacy of dyeing was analyzed by colour strength and colour performance properties; sublimation, wash and light fastness. In comparison with conventional dyed polyester overall dyeing performance was found to be better without affecting tensile strength of polyester which remains almost same whereas thermal stability of solvent dyed polyester was slightly improved compared with aqueous dyed polyester. The results obtained from this study suggest that the GES as a polyester dyeing medium can be a green approach in dyeing of polyester.

Efficient Tabu Search Procedure for Short-Term Planning of Large-Scale Hydropower Systems

AbstractShort-term hydrogeneration scheduling aims at minimizing water consumption for the next 7–15 days on an hourly basis, while satisfying the electrical load as well as many operational, regul...

The concept of coke based proppants for coal bed fracturing

The concept of a new type of coke-based proppant for hydraulic fracturing of coal seams for coalbed methane extraction is introduced. Our solution will facilitate gas inflow into the well due to the fact that the proppants will be resistant to embedment into the coal formation, and gas flow through porous coke grains will be possible even in the case of their partial penetration into the coal rock. Low density of the material will enable suspending the proppant particles in low viscosity frac fluids, which in turn will allow for: decreased flow resistance, minimizing water consumption and better well cleaning. Coke based proppants will allow to increase the performance of hydraulic fracturing operations in coal seams, resulting in improved efficiency of obtaining coalbed methane. The new product will be presumably suitable for stimulation treatments in other, soft rocks or even allow hydrocarbon exploitation from the formations that were previously considered as unproductive.

Effects of gasification condition on the overall performance of methanol-electricity polygeneration system

The operating conditions of coal gasifier have significant effects on the overall system performance of an associated process. This study designs a methanol-electricity polygeneration system and presents a comprehensive discussion about the effects of the ratio of steam to coal, the ratio of O2 to coal, the ratio of carrier gas (CO2) to coal and the CO2 concentration in methanol synthesis gas on different performance indicators. The results show that the steam/coal ratio has slight effects on the overall system performance due to the offset in different sections. An optimal O2/coal ratio exists in the range of 0.84–0.86 to achieve the minimum unit water consumption and the maximum methanol production and energy efficiency, which is almost consistent with the range that the H2 concentration in gasifier syngas reaches the maximum value. The amount of carrier gas CO2 and the CO2 concentration in methanol synthesis gas should be kept at a low level to just meet the requirements of coal pressurization and synthesis reaction. This comprehensive sensitivity analysis can provide some significant guidance for the system design.

Design and manufacture of the cooling system of JUPITER reactor

The experimental investigations carried out in the Plasma laboratory of the Universidad Industrial de Santander, on superficial modification of metallic materials by hybrid discharges of high-voltage and electric arc at low pressures are carried out in the joint universal plasma and ion technologies experimental reactor. The cooling system of the reactor is by water, which means that it is directly connected to the water supply line of the building, which creates a dependence on the system. Additionally, the water supply line is often filled with particles that accumulate in the cooling system, disfavoring the transfer of energy between the water, the vacuum system and the cathode, which can lead to overheating of the reactor and melt the elements that make up the electric power system. In accordance with the above, the present research work consists of designing, building and implementing an efficient cooling system totally independent from the water supply line of the building, which allows to recirculate and minimize water consumption in order to take care of the natural resource.

ENEPIG Reliability - Enhancement by Simple Drop in Process Changes

Soldering on ball grid arrays (BGAs) and dense circuit features is standard practice in the microelectronics industry. Key to the success of this operation is solder joint reliability (SJR). The evaluation of solder joint reliability can be satisfied by high speed shear testing (HSS). HSS testing in combination with representative test vehicles are tools that can be used to gain statistical data in order to evaluate the impact of controlled testing. During such a round of controlled testing in the context of a palladium phosphor ENEPIG process, it was observed that the palladium initiation speed and IMC may be related to HSS results. The focus of this paper is not targeting all the optimizations that can lead to high end reliability performance for solderability. This paper will strive to convey steps that are available to all fabricators to maximize High Speed Shear results (HSS). In this paper, it will be shown that soldermask related pinholes can be overcome by implementing a reduction assisted immersion gold bath. This section will also culminate in SJR improvements and stability. The prevention of pin holes is a complicated multifaceted problem. This paper will address the notion that, if pinholes are evident, an enhanced immersion gold bath can be used to overcome serious corrosion. Disturbances in the nickel deposit can be weaknesses that are open for unusual locally aggressive atom exchange between the gold and the nickel that will result is hyper-corrosion. A reduction assisted gold bath is able to mask such areas with controlled deposition. This paper will demonstrate the effectiveness of the optimized, purpose designed, gold bath in overcoming pinhole related corrosion whilst simultaneously scrutinizing the ability of the reduction assisted gold bath to maintain or enhance the reliability expectations that are benchmarked by traditional immersion gold alternatives. During studies it has also been observed that processing is also instrumental in assuring maximum soldering reliability. Whilst rinsing is an accepted procedure, the degree and method of rinsing is often a controversial topic. This is especially true of vertical processes where fluid exchange is replaced by soaking, or in other words agitation neutral, volume related dilution. Environmentally aware practices err on the side of minimal water consumption. This is a requirement that is influenced or selectively amplified by geographical locations. This technical paper will demonstrate that the palladium initiation is crucial if maximum SJR is to be achieved. This experience was gained in association with a significant OEM. Electrochemical and advanced optical techniques will be used to demonstrate that the SJR in terms of HSS can be correlated to palladium initiation and resultant IMC formations. In summary process adjustments can be employed to improve soldering performance and repetition. An optimized reduction assisted gold bath will come together with processing optimizations to provide a data driven overview to convince fabricators that enhancements to their everyday processes exist and can be implemented by drop in solutions. The data that is included should be as interesting to the automotive industry as it is to the emerging substrate like panel industry (SLP).

Assessment of the environmental impact and economic benefits of the adoption of cleaner production in a Brazilian metal finishing industry

ABSTRACTThe Metal Finishing Industry (MFI) use water and several chemicals in its production chain, which generatesboth liquid and solid hazardous waste. The present study evaluatesthe economic and environmental advantages of implementing cleaner production (CP) in a Brazilian MFI specialized in chrome and zinc. For the economic assessment, we adopted the measures of return on investment and internal rate of return. In order to measure the environmental impact, we used the Mass Intensity Factor. A case study methodology was adopted, with datacollectedthrough observation and semi-structured interviews. The findings indicate that the adoption of CPin this sector encourages the deployment of a Rising Cascades System in Counterflow (RCSC) to minimize water consumption through the reuse and segregation of hazardous solid waste (sludge). The sludge generated may be sold as a byproduct for the production of ceramics. We identifiedopportunities to reduce costs by minimizing waste, although this does require investment. However, the return on such investments mayenable the implementation of CP. The reduction in environmental impact on the ecosystem was significant, with large reductions in hazardous components contained in the sludge being dumped in the environment. The results may guide the development of public policies in Brazil, particularly in the adoption of CP in MFI to disseminate environmental education and increase governmental control.

Airport Water Consumption Footprinting

The study focused on water consumption footprinting and development of water efficiency plan for an airport located in Turkey. Airports are facilities having large water consumption, generally for non-potable purposes such as water cooling systems, fire control, cleaning and washing of vehicles, runways and aircrafts and also public uses (WC, food service). Research period covered 12 months and consumption data obtained from 116 water meters were evaluated for water footprinting. Along a year the airport served to about 12 million passengers and 81 thousand aircrafts. These passengers and aircrafts were served by various services by airport authorities. These services were linked by water consumption directly or indirectly. Study results showed that annual water consumption was about 436000 m3/year. Irrigation, fire control system, cooling towers and terminal WC uses accounted high use with rate of 23%, 7%, 26% and 20 %. While water used for WC changed between about 6-8.5 L per pax, this value was between 1-1.5 L per pax for food consumption. Therefore passenger based uses fluctuated between 6.5-10 L per pax in the airport. Based on this analysis several methods were suggested to minimize water consumption. Among them “training and education of airport staff” was proposed as the most economical solution. Furthermore “improved water consumption monitoring” system could be suggested as applicable method considering economical and physical aspects and should gain priority. Then alternative measures could be chosen based on their economical and physical applicability.

Hybrid Hydrogel with High Water Vapor Harvesting Capacity for Deployable Solar-Driven Atmospheric Water Generator.

The Earth's atmosphere holds approximately 12 900 billion tons of fresh water distributed all over the world with fast replenishment. Atmospheric water harvesting is emerging as a promising strategy for clean water production in arid regions, land-locked areas, and remote communities. The water vapor sorbent is the key component for atmospheric water harvesting devices based on absorbing-releasing process. In this work, a flexible hybrid photothermal water sorbent composed of deliquescent salt and hydrogel was rationally fabricated. It possesses superior water sorption capacity even in low humidity air thanks to the deliquescent salt and maintains a solid form after it sorbs a large amount of water owing to the hydrogel platform. The harvested water could be easily released under regular sunlight via the photothermal effect, and it can be directly reused without noticeable capacity fading. An "easy-to-assemble-at-household" prototype device with 35 g of the dry hydrogel was tested outdoors under field conditions and delivered 20 g of fresh water within 2.5 h under natural sunlight. It is estimated that the material cost of making such a device to supply minimum daily water consumption for an adult (i.e., 3 kg) is only $3.20 (USD). This type of atmospheric water generator (AWG) is cheap and affordable, works perfectly with a broad range of humidity, does not need any electricity, and thus is especially suitable for clean water production in remote areas.

Estimating water consumption based on meta-analysis and MODIS data for an oasis region in northwestern China

A severe water shortage in arid and semiarid regions in China has triggered regulations limiting the use of irrigation water in desert-oasis agricultural systems. To determine the actual water demand of agricultural systems and to develop standards for a rational use of water resources, maize evapotranspiration rates was simulated using meta-analysis of published data, determined land-use and soil properties in Zhangye oasis area and then estimated water consumption with MODIS for arid northwestern China for the 2014 growing season. Farmland in Zhangye oasis totaled 2189.88 km2 and accounted for 25.41% of the total oasis area; crop-protecting forestland totaled 8.56 km2 and accounted for 0.10% of the total oasis area, grassland and unutilized land accounted for 1.85%, 71.48% of the total oasis area, respectively. Soil moisture capacity at saturation ranged from 21.0 to 33.0% and at field capacity from 21.0 to 31.5%. Soil bulk density ranged from 1.36 to 1.58 g cm−3. Using meta-analysis, the simulated maize evapotranspiration rate was 655.91± 20.53 mm. During 2014 growing season, minimum, optimum and maximum water consumption used for agricultural yields and oasis stability was 1.14×109 m3, 1.46×109 m3 and 1.75×109 m3, respectively. In future research, increased big picture and high frequency data will allow operational monitoring of water use and requirements and irrigation at a regional scale.

Water management methods in food industry: Corn refinery as a case study

Water pinch analysis and mathematical optimization are two approaches that can be used in an industrial unit to achieve the minimum water consumption and wastewater generation flowrates. The fundaments of these approaches are based on water reuse. In this study, water pinch analysis and mathematical optimization studies are conducted in a corn refinery to achieve minimum targets. COD and TDS were separately considered as single limiting contaminants in water pinch analysis and water network of a corn refinery plant was modified. Water consumption in the studied corn refinery decreased from 1800 m3/day to 1235 m3/day if COD was taken into account and to 1152 m3/day if TDS was. The same results are achieved for single contaminant in mathematical optimization as well. The single contaminant approaches in the most cases are useless due to process limitations in water reuse. Therefore, mathematical optimization with multi-contaminants approach is conducted to design a reasonable water distribution network. Simultaneous consideration of COD and TDS in a multi-contaminants optimization resulted in 30% decrease in water consumption and required freshwater was reduced to 1260 m3/day.

Optimal daily generation scheduling of large hydro–photovoltaic hybrid power plants

Joint operation of large-scale renewable energy sources (e.g., hydro and solar) has become a trend in modern power systems, and more operators of existing hydropower reservoir systems are adopting it. This study aimed to improve guidance for the daily generation scheduling of a large hydro–photovoltaic (PV) power plant. First, a robust optimization model that accounts for uncertain PV power generation was formulated, in which the delivered power output of the hybrid system and hydro unit status are robust decision variables. To deal with the complexity of the model solution, a three-layer nested framework was proposed to solve the generation scheduling problem in a hierarchical structure. In the outer layer, a direct search algorithm optimizes the delivered power output of the system, aiming to maximize energy production while satisfying specified load characteristics. In the middle and inner layers, a cuckoo search algorithm and dynamic programming technique optimize the hydro unit status and load dispatch strategies, respectively, with the objective of minimizing water consumption. Finally, a decision interval on delivered power output of the system was derived by relaxing the load characteristic constraint. Results for a case study using China’s Longyangxia hydro–PV power plant indicated that the robust optimization model and the three-layer nested approach could provide effective power generation plans for the hybrid system within a reasonable time. Compared with actual operation, the power generation plans could increase energy production of the hybrid system by 1.9% while decreasing total online time of the hydro units by 9.7%. Therefore, the proposed method could improve guidance for the hydro–PV power plant’s generation scheduling. In practice, conjunctive use of the power generation plan and the decision interval could also inform flexible decision-making for plant operations management.

INFLUENCE OF BIOLOGIZATION AND CHEMICALIZATION ON WATER CONSUMPTION OF CROPS IN FODDER CROP ROTATIONS

The work presents the results of research into the effect of biologization (intercropping legume component with grain crops) and chemicalization (use of mineral fertilizers) applied in each fi eld of fodder crop rotation on the moisture content of leached chernozem in the conditions of the forest-steppe zone of Western Siberia. Water consumption and crop productivity in six-fi eld fodder crop rotations over four years of the second rotation were studied. Only recognized locally-bred crop varieties were cultivated in the experiment, such as Krasnoobsky oat, Acha barley, pea Novosibirets, vetch Priobskaya 25, alfalfa Flora, awnless brome Rassvet, hybrid maize Obsky 140 SV and fodder bean Sibirskiye. It was established that intercropping of the legume component caused the increase in the consumption of productive moisture reserves from the soil by fodder agrocenoses from 66 mm to 84 mm and the application of mineral fertilizers resulted in the moisture consumption increase of up to 74 mm. The use of methods for fodder crop rotation improvement led to the increase in the total water consumption of fodder crops. As a result of mineral fertilizer input it increased from 244 mm to 252 mm, and due to the intercropping of legume component it rose up to 262 mm. With regard to increasing the consumption of productive moisture reserves from the soil layer of 0-100 cm, crops ranked in the following order: perennial grasses – silos – fodder-grain crops – cover crops, whereas with regard to increasing the total water consumption they ranked in reverse order. The use of chemical agents increased the yield of dry matter by 1.6 times, while water consumption coeffi cient decreased by an average of 2.2 times in the crop rotation. Application of biologization led to the yield increase by 1.4 times, reducing water consumption coeffi cient by 1.9 times. In the control crop rotation, maize consumed the least amount of moisture (346 m 3 /ton of dry weight), and the most moisture was consumed by the grain part of barley (2933 m 3 /t of dry weight). When applying mineral fertilizers, the maximum and minimum water consumption fell on the same crops – 290 m 3 /t and 1087 m 3 /t dry weight respectively. When the legume component was sowed in each crop rotation fi eld, the minimum moisture consumption was in the fi elds with awnless brome intercropped with alfalfa, namely 384 m 3 /t dry weight, while the maximum consumption was in the fi elds with barley and pea grains – 1199 m 3 /t dry weight.

Use of Nonlinear Membership Functions and the Water Stress Index for the Environmentally Conscious Management of Urban Water Systems: Application to the City of Morelia

This article proposes a multiobjective optimization strategy based on a fuzzy formulation for the sustainable design and planning of water supply chains in urban areas that considers simultaneously economic and environmental objectives. Harvested rainwater and reclaimed water are considered as alternative sources to reduce freshwater consumption while maximizing water revenues and minimizing land usage. As opposed to other models that attempt to minimize water consumption, this work seeks to minimize the water stress index, which quantifies the impact of freshwater consumption with respect to the specific location where the withdrawals take place. We illustrate the capabilities of this approach through its application to a real case study based on the city of Morelia in Mexico, in which we show that the use of alternative water sources along with an appropriate water distribution plan can reduce the impact over natural reservoirs.