Minimum Water Consumption Research Articles

Aspects of formation of soil water regime and water consumption of corn under subsurface drip irrigation

The results of experimental researches on studying of features of formation of a water mode of soils, water consumption processes, and corn yield under different schemes of irrigation pipelines (IP) under subsurface drip irrigation (SDI) in the Steppe of Ukraine. The wetting zone of dark-chestnut residual-saline sandy soil (SI "SF "Brylivske") changed. There is a shift of the center relative to the drip water outlet into deeper horizons of the soil profile (up to 52 cm) with the increasing norm; soil layer 0-15 cm is almost not moistened, regardless of watering rate. At a distance of IP 1,0 m closing of wetting zones, occur at irrigation rates of 2,7 m3/100 running meter (r. m), and at a distance of IP 1,4 m does not occur even at irrigation rates of 3,7 m3/100 r. m, while the depth of wetting reaches 90 cm. The wetting zone of chernozem sandy loam on the loess species (SI "SF "Velyki Klyny") with irrigation rates of 2,7 m3/100 r. m was observed on the soil surface. The maximum depth of wetting, with irrigation norms of 3,7 m3/100 r. m, reached 70 cm with a maximum diameter of 79 cm at a depth of 25 cm. Closing of wetting zones was not observed.
 Studies at SI "SF "Brylivske" have confirmed that the depth of IP placement (on the soil surface or at a depth of 30 cm) influenced the formation of the soil water regime and the corn yield. The minimum total water consumption was 6271 m3/ha under drip irrigation (DI) (IP 1,4 m), 17 % more than SDI (IP 1,4 m), and 29% more than SDI (IP 1,0 m). The highest yield was obtained in the case of DI (IP 1,4 m) of 15,72 t/ha. SDI (IP 1,0 m) received 13,93 t/ha, and SDI (IP 1,4 m) received 13,50 t/ha.
 The distance between the IP in 1,0 m and 1.4 m of the SDI system did not significantly affect corn yield (13.93 and 13.50 t/ha, respectively), but at a distance of IP 1.4 m, the water consumption ratio was 6.8% less compared to IP 1,0 m. The value of the irrigation rate in the variants SDI (IP 1.0 m) was higher than SDI (IP 1,4 m) by 13,6 %. Therefore, in terms of irrigation water consumption and capital expenditures, the SDI (IP 1,4 m) is more economical.
 Experimental studies conducted in the SI "SF "Velyki Klyny" show that the depth of placement of IP (on the soil surface or at a depth of 20 cm) did not affect the corn yield. For DI (IP 1,0 m) the yield was 12,00 t/ha and for SDI (IP 1.0 m) was 12,10 t/ha, with a water consumption ratio of 533,8 m3/t, and for DI (IP 1,0 m) by 3,6 % more.
 The research results confirm the importance of the parameters of SDI system for the formation of soil water regime and, accordingly, the realization of the potential of varieties and hybrids of crops for their cultivation by SDI.

Studies of ventilation and thermal comfort in different wind tower-room configurations considering humidification for a warm climate of Mexico

Air conditioning systems in buildings demand a high energy consumption and will only be exacerbated by the threat of climate change, as coping with the increased temperatures will require a higher consumption of electricity for ventilation and cooling. The use of passive techniques to save energy and provide thermal comfort inside the buildings should be a priority for research. This work investigates the effectiveness of the passive natural ventilation system called the wind tower (windcatcher) to provide thermal comfort in a room without and with air humidification, for warm climatic conditions. The study was carried out using CFD considering three-dimensional turbulent flow for the continuous phase and a Lagrangian approach for the discrete phase. In addition, the parameters and indices of natural ventilation and thermal comfort were calculated. 54 different configurations of the wind tower and the room outlet window were evaluated. The influence of a chamfer in the tower and the optimization of water consumption in the humidifier were also investigated. The results showed that the selection of a suitable configuration and the use of a chamfer, can substantially improve ventilation and thermal comfort. In addition, the optimal mass flow rate for humidification that provides a sensation of neutral thermal comfort and minimal water consumption was found. The use of a wind tower and the application of humidification at the critical hours of the day, will provide thermal comfort throughout the day with a predicted percentage of dissatisfied lower than 10%. These results show that low energy consuming systems utilizing natural ventilation and air humidification in a wind tower-room system can be sufficient for appropriate cooling and thermal comfort.

Analysis and evaluation of long-term changes in the main hydrometeorological characteristics on the Valdai

The relevance of the topic is due to the continuing interest in the regional consequences of climate warming and the updating of estimates of long-term changes in the extended series of hydrometeorological observations. The aim of the study was to analyze the long-term changes in air temperature, precipitation, the maximum depth of soil freezing, the height of snow cover, the regime of underground water and river flow for the total observation period of 1939–2018 based on the materials of the Valdai Research Hydrological Laboratory. The average annual air temperature has increased by 1.4°C since 1988, with the most significant increase in air temperature in January-February and in March. Annual precipitation totals increased by an average of 114 mm compared to 1939–1979, the increase in precipitation occurred mainly in the colder months of the year. The maximum depth of soil freezing decreased by an average of 2 times. At the same time, on the studied small watercourses (the Taiga log and the river Polomet'). The average annual flow of rivers has not changed significantly. Multidirectional trends are observed in the long-term fluctuations of the maximum spring flow of rivers. Ground water levels did not increase in 1991– 2016, and in some upper aquifers they decreased. The largest replenishment of groundwater reserves in the spring began to occur on average 2 weeks earlier. Over the past 30 years, the minimum 30-day winter water consumption has not increased, and the variation of fluctuations in the minimum 30-day summer-autumn water consumption of rivers has increased

Onsite Graywater Treatment By Decoupled Electro-Peroxone Process with Recycled Effluent

This study investigates the efficacy of a decoupled electro-peroxone (E-peroxone) process for the lab-scale treatment of synthetic graywater. The E-peroxone process generally integrates conventional ozonation with in situ production of hydrogen peroxide (H2O2) in a single reactor for the transformation of ozone (O3) to hydroxyl radicals (*OH). In this study, however, the electrolysis of H2O2 generation via cathodic oxygen reduction was performed separately in order to finely control the H2O2 utilization for the E-peroxone process and to prevent the degradation of polytetrafluoroethylene (PTFE) coated carbon cathodes by highly reactive *OH. The dosage of the electro-generated H2O2 into a main reactor was optimized to enhance the performance of synthetic graywater treatment by facilitating the *OH formation. Under the optimal condition, the decoupled E-peroxone system treated synthetic graywater with initial chemical oxygen demand (COD) of 358 mg O2/L, total organic carbon (TOC) of 96.9 ppm, biochemical oxygen demand (BOD) of 162 mg O2/L, and turbidity of 11.2 NTU; the system consistently achieved removal of 89% COD, 86% TOC, 91% BOD, and 95% turbidity after 90-minute treatment, producing an effluent acceptable for discharge and non-potable applications such as toilet flushing. Part of the effluent was also recycled back into the system for H2O2 generation to minimize water consumption. This recycling process was successfully repeated consecutively for four cycles. Although the duration to reach the desirable concentration of H2O2 slightly increased from cycle to cycle, the system maintained comparable treatment performance with COD and TOC removal above 85% and 73%, respectively. Given these promising results in single-pass treatment and closed-loop recycling of graywater, the decoupled E-peroxone system can provide effective decentralized wastewater treatment for remote or water-sensitive areas. Figure 1

Onsite Graywater Treatment in a Two-Stage Electro-Peroxone Reactor with a Partial Recycle of Treated Effluent.

The efficacy of an uncoupled electro-peroxone (E-peroxone) prototype reactor system for the treatment of synthetic graywater is determined. The two-stage E-peroxone process integrates ozonation with the in situ production of hydrogen peroxide (H2O2) in a first stage reactor before ozone (O3) is converted via the peroxone reaction to a hydroxyl radical (•OH). The two-stage prototype reactor system allows for the generation of H2O2 via cathodic oxygen reduction in the first-stage reactor before mixing with O3 in the second-stage reactor. This approach prevents the degradation of polytetrafluoroethylene (PTFE) coated carbon cathodes by •OH that takes place in a single well-mixed reactor that combines electrochemical peroxide generation with O3. The dosage of H2O2 into the second-stage reactor is optimized to enhance graywater treatment. Under these conditions, the uncoupled E-peroxone system is capable of treating synthetic graywater with an initial chemical oxygen demand (COD0) of 358 mg O2/L, a total organic carbon (TOC0) of 96.9 mg/L, a biochemical oxygen demand (BOD0) of 162 mg O2/L, and a turbidity of 11.2 NTU. The two-stage electro-peroxone system can reduce the initial COD0 by 89%, the TOC0 by 91%, BOD0 by 86%, and the turbidity by 95% after 90 min of treatment. At this performance level, the reactor effluent is acceptable for discharge and for use in nonpotable applications such as toilet-water flushing. A portion of the effluent is recycled back into the first-stage reactor to minimize water consumption. Recycling can be repeated consecutively for four or more cycles, although the time required to achieve the desired H2O2 concentration increased slightly from one cycle to another. The two-stage E-peroxone system is shown to be potentially useful for onsite or decentralized graywater treatment suitable for arid water-sensitive areas.

An IoT Based Farm Irrigation System by Periodical Maintenance of Soil Moisture Value

India is the largest country and the main profession of our Indians is agriculture. There are many dry areas in India due to lacking of rainfall. So, irrigation becomes difficult. There is a need for water to grow the crops. The main objective is to minimize water consumption and water wastage. The objective of this work is to design a device for automated watering for a crop and was handled remotely by farmer. The system will help to identify whenever the soil goes dry, pump will automatically start watering. This process saves time and low electricity consumption for the device. The devise is designed by training moisture sensors with adequate power supply. The processor controls and makes decision whenever it receives signal from the transmitter. It setup a pump for water flow and to create a message system for communication purpose. An automatic maintenance of farm irrigation with soil moisture control was performed by Arduino. The soil moisture sensor and Relay circuit was used. This system senses the temperature of the land soil and moisture of the soil periodically. If the value is below threshold value, the pump will switch on. The irrigation system is necessary and useful for poor rain areas, unplanned water management, not proper storage facilities and more volume of water wastage. Hence, an IoT (Internet of Things) based farm irrigation system is developed. This system will be useful in all weather and climatic conditions.

Evaluation of subcooled MQL in cBN hard turning of powder-based Cr-Mo-V tool steel using simulations and experiments

Metal cutting fluids for improved cooling and lubrication are an environmental risk and a health risk for workers. Minimizing water consumption in industry is also a goal for a more sustainable production. Therefore, metal cutting emulsions that contain hazardous additives and consume considerable amounts of water are being replaced with more sustainable metal cutting fluids and delivery systems, like vegetable oils that are delivered in small aerosol droplets, i.e., via minimum quantity lubrication (MQL). Since the volume of the cutting fluid in MQL is small, the cooling capacity of MQL is not optimal. In order to improve the cooling capacity of the MQL, the spray can be subcooled using liquid nitrogen. This paper investigates subcooled MQL with machining simulations and experiments. The simulations provide complementary information to the experiments, which would be otherwise difficult to obtain, e.g., thermal behavior in the tool-chip contact and residual strains on the workpiece surface. The cBN hard turning simulations and experiments are done for powder-based Cr-Mo-V tool steel, Uddeholm Vanadis 8 using MQL subcooled to −10 °C and regular MQL at room temperature. The cutting forces and tool wear are measured from the experiments that are used as the calibration factor for the simulations. After calibration, the simulations are used to evaluate the thermal effects of the subcooled MQL, and the surface residual strains on the workpiece. The simulations are in good agreement with the experiments in terms of chip morphology and cutting forces. The cutting experiments and simulations show that there is only a small difference between the subcooled MQL and regular MQL regarding the wear behavior, cutting forces, or process temperatures. The simulations predict substantial residual plastic strain on the workpiece surface after machining. The surface deformations are shown to have significant effect on the simulated cutting forces after the initial tool pass, an outcome that has major implications for inverse material modeling.

Short-Term Hydro Generation Scheduling of the Three Gorges Hydropower Station Using Improver Binary-coded Whale Optimization Algorithm

The short-term hydropower generation scheduling (STHGS) is a complicated problem in the utilization of hydropower and water resources. An improved binary-coded whale optimization algorithm (IBWOA) is proposed in this paper to solve the complex nonlinear problem. The STHGS problem is divided into unit combination (UC) subproblem and economic load distribution (ELD) subproblem. For the UC subproblem, we use the sigmoid function (SF) to generate a binary array representing the start/stop state of the unit. The whale algorithm's search mechanism is optimized, and the inertia weight and perturbation variation strategy are introduced to improve the algorithm's optimization ability. Each generation solution is optimized by repairing the minimum uptime/downtime constraint and the spinning reserve capacity constraint. For ELD subproblem, the optimal stable load distribution table (OSLDT) is used to distribute the load quickly. The Mutation mechanism and the Locally balanced dynamic search mechanism compensate for the non-convex problems caused by start-stop constraints and stable optimal table methods. Finally, the proposal is applied to solve the STHGS of the Three Gorges Hydropower Station. When the water head is 75 m,88 m, and 107 m, the minimum water consumption calculated by the IBWOA algorithm is 1,058,323,464 m3, 892,524,696 m3, and 745,272,216 m3, respectively. Compared with the traditional whale optimization algorithm, the water consumption of the IBOWA algorithm corresponding to 75 m, 88 m, and 107 m water heads is reduced by 0.76%, 0.26%, and 0.05%, respectively. The comparison between the IBWOA algorithm and other heuristic algorithms shows that the IBWOA has good feasibility and high optimization accuracy.

Minimizing water consumption for sugar and lignin recovery via the integration of acid and alkali pretreated biomass and their mixed filtrate without post-washing

Excessive post-washing of pretreated biomass leads to huge water consumption and chemical loss. To address this issue, parallel HOAc and NaOH pretreatments of biomass followed by integration of their biomass and filtrate were investigated. Pretreatment effectiveness including morphology, crystallinity, and component recovery, were elucidated. Results showed that HOAc and NaOH in the mixed filtrate were neutralized to achieve a pH of around 4.80 prompting the alkali lignin precipitation. Lignin (46.01 and 48.38 g/kg-biomass for hemp and poplar, respectively) exhibiting comparable FTIR characteristics with the commercial alkali lignin was recovered. Compared to sodium acetate buffer as a control, integrating HOAc and NaOH pretreated biomass and their mixed filtrate for enzymatic hydrolysis boosted total sugar concentration (hemp: 42.90 vs. 38.27 g/L; poplar: 43.18 vs. 38.76 g/L) without compromising glucose yield (hemp: 70.86 vs. 70.69%; poplar: 66.48 vs. 69.48%) but improving xylose yield (hemp: 60.10 vs. 35.92%; poplar: 56.90 vs. 29.39%).

Sustainable atmospheric fog water generator through superhydrophobic electrospun nanocomposite fibers of recycled expanded polystyrene foams

In recent years, the production of disposable plastic products is increasing day by day and resulting in global growing concern that it poses to the environment. Microorganisms hardly resolve these types of plastic wastes; therefore, recycling the value-added materials is very important. Recycling and reusing plastic wastes to produce superhydrophobic nanofibers for atmospheric clean water production could be a partial solution to address the environmental issues. Herein, superhydrophobic-hydrophilic nanocomposites fibers were fabricated using recycled expanded polystyrene (REPS) as inspired by the fog-harvesting capability of Stenocara beetles in the Namib Desert. The REPS were electrospun with various proportions of titanium dioxide (TiO2) nanoparticles and aluminum (Al) microparticles. The fiber morphology, surface hydrophobicity, thermal properties, and fog water-harvesting performance of the nanocomposite fibers were studied. The as-prepared nanocomposites fibers with a 10% inclusion of combined micro-and nanoparticles exhibit superhydrophobic properties with a water contact angle of 157° and daily water productivity of more than 1.35 liter/m2 of nanocomposites. The expenses of materials to produce such nanocomposites needed to supply the minimum daily water consumption for a two-member household (6 liters) are only US$2.67. These nanocomposites are inexpensive, reusable, do not require additional energy consumption, and are particularly suitable for producing clean water in arid areas. This study offers a new technology for the mass production of clean water through nanotechnology at a relatively low cost.

Experimental study of a string-based counterflow wet electrostatic precipitator for collection of fine and ultrafine particles

ABSTRACT Wet electrostatic precipitators (WESP) have been widely studied for collecting fine and ultrafine particles, such as diesel particulate matter (DPM), which have deleterious effects on human health. Here, we report an experimental and numerical simulation study on a novel string-based two-stage WESP. Our new design incorporates grounded vertically aligned polymer strings, along which thin films of water flow down. The water beads, generated by intrinsic flow instability, travel down the strings and collect charged particles in the counterflowing gas stream. We performed experiments using two different geometric configurations of WESP: rectangular and cylindrical. We examined the effects of the WESP electrode bias voltage, air stream velocity, and water flow rate on the number-based fractional collection efficiency for particles of diameters ranging from 10 nm to 2.5 μm. The collection efficiency improves with increasing bias voltages or decreasing airflow rates. At liquid-to-gas (L/G) as low as approximately 0.0066, our design delivers a collection efficiency over 70% even for fine and ultrafine particles. The rectangular and cylindrical configurations exhibit similar collection efficiencies under nominally identical experimental conditions. We also compare the water-to-air mass flow rate ratio, air flow rate per unit collector volume, and collection efficiency of our string-based design with those of previously reported WESPs. The present work demonstrates a promising design for a highly efficient, compact, and scalable two-stage WESPs with minimal water consumption. Implications: Wet Electrostatic Precipitators (WESPs) are highly effective for collecting fine particles in exhaust air streams from various sources such as diesel engines, power plants, and oil refineries. However, their large-scale adoption has been limited by high water usage and reduced collection efficiencies for ultrafine particles. We perform experimental and numerical investigation to characterize the collection efficiency and water flow rate-dependence of a new design of WESP. The string-based counterflow WESP reported in this study offers number-based collection efficiencies >70% at air flow rates per collector volume as high as 4.36 (m3/s)/m3 for particles of diameters ranging from 10 nm – 2.5 μm, while significantly reducing water usage. Our work provides a basis for the design of more compact and water-efficient WESPs.

Integrated solar – Windcatcher with dew-point indirect evaporative cooler for classrooms

This work investigates the performance of a novel passive ventilation and cooling system for a classroom in hot and semi-arid climate. The system integrated a combined solar chimney – windcatcher system with a fan-assisted cross-flow dew point indirect evaporative cooler (DP-IEC) to condition the fresh air supplied to the space. The classroom exhaust, driven by the solar chimney, was used to cool a double layer window and reduce the radiation asymmetry. A mathematical model was developed to size the system’s components and optimize its hourly operation to achieve the required thermal comfort and indoor air quality at minimal fan energy and DP-IEC water consumption. The integrated model was validated with published data in the literature. The validated integrated model was used to simulate the proposed system for a typical classroom in the semi-arid climate of Beqaa, Lebanon. It was found that the cooling system was able to meet the space thermal and air quality requirements throughout the summer with a temperature of 24.8 °C (±0.3 °C), a relative humidity ranging between 43% and 58%, and a CO2 level less than 900 ppm. Moreover, the radiation asymmetry was less than 3.5 ℃ which is within the acceptable range (less than10 °C). The system’s highest energy and water consumptions of 3.6 kWh/day and 185 L/day occurred during the peak load month of July where the DP-IEC was operated with a high fresh air flowrate of 1 kg/s with no bypass throughout most of the day. Over the summer period (May to September), the system achieved 70% reduction in operational cost as compared to the conventional systems.

Optimization of closed-cycle oil recovery: a non-thermal process for bitumen and extra heavy oil recovery.

Energy from unconventional resources includes bitumen and extra-heavy oil that represent two-thirds of the known resources in the world. Extra-heavy oil and bitumen are currently recovered using thermal processes having a large carbon footprint and significant environmental impacts on water resources. A novel process is proposed: closed-cycle oil recovery (C-COR). C-COR is a greener alternative to provide energy from these unconventional resources with minimal water consumption. C-COR relies on recovering oil solubilized within a single-phase microemulsion, eliminating the need for viscosity reduction to both mobilize heavy oil or to transport it. Proof-of-concept work was conducted using conventional phase behavior experiments with extracted oil and surfactant formulations to develop a surfactant formulation for oil recovery using C-COR. As a part of process development and scale-up, we conducted flow experiments presented in this paper. We learned that a high degree of surfactant adsorption, which negatively impacted the C-COR process, resulted at low pH levels. These findings required modifying traditional static batch tests (phase behavior studies) using actual oil sand instead of the extracted oil. These unorthodox tests revealed that surfactant adsorption caused low oil solubilization and that alkali can be used to reduce adsorption, improving oil solubilization. In addition, unique flow experiments were designed to optimize the delivery and recovery process and are presented in this paper. The unique batch tests and flow experiments were conducted using oil sands from Canada to optimize the process. The proposed optimized approach would employ intermittent flow (soaking) that would result in the fastest recovery of about one-third of the OOIP, followed by continuous injection to recover an additional 10% OOIP, ending with thermal enhancement to recover another 25% OOIP for a total of 61%.

Comparative Study of Agarophytes - Gracilaria edulis and Gelidiella acerosa as Biostimulant and Application of Agar for Water-holding in Soil and Plant Growth Promotion

Background: Seaweeds and its derivatives are extensively used as biostimulants in horticulture and agriculture as a replacement for chemical fertilizers. G. edulis and G. acerosa are easily cultivable and economically important seaweeds. They are a rich source of phytohormones, amino acids, antibiotics, vitamins, micro, macro elements and agar. Such natural products have great demand and been commercialized these days to promote sustainable agriculture. Dried and finely powdered algal biomass is used directly as a biostimulant. Algal polysaccharides such as agar can be an innovative alternative to synthetic polymers used in horticulture as they contain active biostimulant compounds and also reported to hold water in the soil that aids plant growth with minimum water consumption than usually required. A. aritis being one of the most consumed leafy vegetables throughout the world can be harvested indoors with added nutrients and minimal water utilization.Methods: The field trial is a comparative evaluation of the two selected species of agarophytes for promoting plant (A. aritis) growth and the extracted agar tested for germination tests, bio-stimulatory property under water stress. Growth parameters were recorded after three weeks. The agarophytes were also qualitatively screened for phytochemicals and WD-XRF analysis.Result: The present work will be a supplementary contribution for assessing agarophytes with biostimulant properties and the characteristic agar gels that expand plant tolerance to abiotic stresses, thus constituting an alternative to synthetic plant protection products.

CONTROL OF WATER CONSUMPTION OF ENTERPRISES OF ROSTOV REGION

. In this paper we consider the hierarchical two-level dynamic model of water consumption of enterprises of Rostov region. On the top level there is region’s government (supervisor) and on the lower level there are enterprises grouped by the types of economic activity. Such grouping allows one to avoid modelling all region’s enterprises which consumes water (there were about 500 enterprises in 2019) while still considering the uniqueness of the enterprises. We consider three groups of enterprises which, according to statistics, are the main water consumers. The enterprises aim to maximize their production while supervisor seeks to minimize water consumption and to maximize production. We introduce generalized goal function for supervisor, which it seeks to maximize depending on what it values the most – production or water consumption. Using the model, we study how supervisor is able to control water consumption of the enterprises with extra fees and how it may affect production level. We provide algorithms for model identification and study. For model identification we use least squares method and the data from publicly available sources. To study model we use Pontryagin’s maximum principle and quality representative scenarios method. We provide various calculations for the model with different supervisor’s preferences. We show that it is possible to reduce water consumption by more than 50 % with production decrease being less than 25%

The implementation of green industry standard batik industry to develop eco-friendly

Since UNESCO has established batik as Indonesia’s cultural heritage, batik has become increasingly recognized internationally. However, many parties are concerned about environmental problems due to the waste from the batik production process. Therefore, the batik industry must change its thinking about the concept of environmentally friendly industries by applying green industry principles. This paper will explain the application of green industry principles that can be fulfilled at every stage of the batik production process. The technical and management requirements are covered by the Green Industry Standard (GIS) for the batik industry which is stipulated by the Minister of Industry Regulation Number 39 of 2019. GIS includes the efficiency of input materials, namely raw and auxiliary materials as well as the selection of alternative materials that are more environmentally friendly, energy-efficient and minimize water consumption and pay attention to the principles of water conservation, good waste treatment, and limitation of air emissions due to the use of technology and low-carbon energy options. It is expected that with the application of green industry principles, the batik industry will not only experience an increase in the economic sector but become an environmentally industry.

Cooling water sources diagram

Recirculating cooling water systems are used to absorb heat in the heat exchanger network, usually operating in a parallel configuration and returning water to the cooling tower with a higher temperature. This configuration receives the fresh cooling water directly without any previous reuse. While this configuration is simple to operate, it leads to inefficient use of the cooling water. On the other hand, a series configuration can reduce the cooling water flow rate, but the complex arrangement and sometimes thermodynamic restrictions lead to higher operational costs. This paper proposes simplifying the network structure through a series-parallel configuration and determines the minimum water flow rate in the cooling system without affecting the heat load removal from the process heat exchangers, using the Cooling Water Sources Diagram (CWSD). Minimizing water consumption and increasing the water return temperature lead to an improvement in the cooling tower's efficiency, which reduces its operational cost. One case study with different scenarios is presented to cover several cooling system characteristics to demonstrate the proposed new tool's applicability and efficiency. The results are compatible with those observed in the literature, being superior in some cases, either in terms of cost values or generating different possible networks.

Modeling oasis dynamics driven by ecological water diversion and implications for oasis restoration in arid endorheic basins

To achieve sustainable development, ecological water diversion has been implemented as a management tool to recover degraded oasis ecosystems in arid endorheic basins. Aiming to explore oasis response and identify appropriate objectives for oasis restoration, this study used a conceptual lumped ecohydrological model. Qingtu Oasis in the Shiyang River basin, Northwest China, was used as a case study to test this model. The model coupled groundwater budget, oasis response, and evapotranspiration dynamic modules. The model structure was clear and reasonable, and the calculation was of low cost. The application in Qingtu Oasis verified the model's effectiveness. The model was able to effectively capture the ecohydrological response attributed to the recovering of Qingtu Oasis in response to ecological water diversions occurring during the last decade. Combined with scenario analysis, the simulation indicated that Qingtu Oasis was fragile and largely dependent on ecological water diversion. Ecological responses were positive and non-linearly correlated with water input, resulting in an optimal water input that produced maximum water benefit by minimum water consumption. The ideal point method was useful in identifying this cost-effective water volume for oasis restoration. For Qingtu Oasis, the optimal water diversion was 45 million m3, which would recover the oasis to 29.16 km2 with an NDVI of 0.41. The current oasis conditions approach the optimal status, and ecological water diversion was suggested to continue and maintain the current oasis status. The volume of 45 million m3 could be taken as an upper threshold of water diversion, because above this threshold, water consumption would not result in water benefits effectively. This study proposed a practical tool for ecohydrological process simulation.

Study of optimal allocation of water resources in Dujiangyan irrigation district of China based on an improved genetic algorithm

Abstract In order to distribute water resources reasonably, it is advantageous to make full use of resources and produce high economic and social benefits. Taking the Dujiangyan irrigation area of China as an example, we discuss the idea of establishing and solving the optimal allocation model of water resources. With this aim, a two-dimensional constraint model with highest economic value, minimum water shortage, minimum underground water consumption and necessary living water demand was established. In order to solve this model, we improved a multi-population genetic algorithm, extending the genetic optimization of the algorithm into two dimensions, taking population as the vertical dimension and the individual as the horizontal dimension, and transforming the cross genetic operator to copy the genetic (crossover) operator and the mutation operator to only act on the vertical dimension, so as to optimize the allocation of such discrete objectives of water resources in the irrigation area with a particular model suitable for the region. The distribution results successfully control the water shortage rate of each area at a low level, which saves the exploitation of groundwater to the maximum extent and produces high economic benefits. The improved algorithm proposed in this paper has a kind of strong optimization ability and provides a new solution for the optimization problem with multiple constraints.

Performance evaluation of shell and tube heat exchanger through ANN and ANFIS model for dye recovery from textile effluents

ABSTRACT Performance of Shell and Tube Heat Exchanger for treatment of textile industry wastewater as a secondary treatment process is reported. An Adaptive Neuro-Fuzzy Inference System and Artificial Neural Network models were used for predicting the accuracy of the process. Condensate flow (m3/hr), feed inlet temperature (°C) and steam flow (kg/cm) for textile effluents were used to predict the condensate temperature (°C). The accuracy of the developed model was validated using Absolute Mean Relative Error, Root Mean Square, and Absolute fraction of variance. The different combinations of input parameters were determined with preceding parameters of the model. Comparison of the models indicated the advantage of ANFIS model over ANN model. Seventh configuration values of ANN reported 0.971%, 1.175%, and 0.9456 of the Absolute Mean Relative Error, Root Mean Square, and Absolute fraction of variance respectively. Similarly, the ANFIS reported 0.381%, 0.532%, and 0.9998 of the Absolute Mean Relative Error, Root Mean Square, and Absolute fraction of variance respectively. ANFIS model was found to be more effective in predicting the condensate temperature with a high Absolute fraction of variance R2 = 0.9998 the results were in line with the experimental data. In the present study the complication of nonlinear process has been resolved using ANFIS modeling technique. The treated water could be recycled using this process. Optimization of the process parameters helps in minimizing water consumption and offers economic benefits for wastewater treatment.