Water Shortage Issues Research Articles

Comprehensive study on the detrimental effects of fossil fuel exploration and pipe laying in deltaic region

Thanjavur is the “Granary of South India”. As the prosperous capital of Chola kingdom it was praised as “Chola Naadu Sorudaithu” (the land that had abundant food). Now, due to Cauvery water shortage issues, the farmers had to be content with single crop a year. Adding to the woes are urbanization and development programs which lack foresight or long term plans that exploit natural resources without a well-articulated thought process. Presently the net sown area in the deltaic region is about 11.87 lac hectares. In the guise of national interests, there is a pursuit of these regions by agencies- public sector undertakings with vested interests. The oil exploration in Cauvery basin (Narimanam block) by Public Sector Undertakings, estimated lignite reserves of 36000 million tonnes and gas reserves and 104.7 billion cubic metres (CBM Coal Gas Methane), which has placed the deltaic region in the corporate radar. Environmentalists and legislators have also turned a blind eye towards the detrimental aftermaths upon the execution of crude product explorations on our cultivable lands.

3D-Printed, All-in-One Evaporator for High-Efficiency Solar Steam Generation under 1 Sun Illumination.

Using solar energy to generate steam is a clean and sustainable approach to addressing the issue of water shortage. The current challenge for solar steam generation is to develop easy-to-manufacture and scalable methods which can convert solar irradiation into exploitable thermal energy with high efficiency. Although various material and structure designs have been reported, high efficiency in solar steam generation usually can be achieved only at concentrated solar illumination. For the first time, 3D printing to construct an all-in-one evaporator with a concave structure for high-efficiency solar steam generation under 1 sun illumination is used. The solar-steam-generation device has a high porosity (97.3%) and efficient broadband solar absorption (>97%). The 3D-printed porous evaporator with intrinsic low thermal conductivity enables heat localization and effectively alleviates thermal dissipation to the bulk water. As a result, the 3D-printed evaporator has a high solar steam efficiency of 85.6% under 1 sun illumination (1 kW m-2 ), which is among the best compared with other reported evaporators. The all-in-one structure design using the advanced 3D printing fabrication technique offers a new approach to solar energy harvesting for high-efficiency steam generation.

Investigation of Influence of Membrane Type on Water Recovery by Pressurized Membrane Processes from Textile Washing Wastewaters

Developments in industrial activities around the world lead to increase water consumption and to become widespread industrial water pollution problems. This situation accompanied by increasing water shortage issues needs to be realized technological applications which include recovering water in reusable quality from wastewaters of excessive water-consuming industries. In this study, recovering water in reusable quality from textile washing wastewaters having 6.22±0.03 pH, 1130±321 mg TDS/L, 2362±727 mg COD/L and 744±234 mg TOC/L was aimed using ultrafiltration (UF), nanofiltration (NF) and reverse osmosis (RO) membrane processes. In this respect, effect of membrane type as the main parameter for real-scale installations on reusable water quality was examined. Experiments were performed using four membranes each for UF and NF and five for RO at the conditions of original pH, 25 oC and 300 rpm cross-flow rate in trans-membrane pressures of 8, 12 and 40 bar for UF, NF and RO, respectively. At the experiments, the best performances were obtained by UH050, NF270 and LFC-3 membranes for the aforementioned order of the processes. This study was proved that reuse water with pH 6.34, 13 mg TDS/L, 34 mg COD/L and 14 mg TOC/L could be produced from textile washing wastewaters using UF/NF/RO combined system.

The effects of surface wettability on the fog and dew moisture harvesting performance on tubular surfaces.

The efficient water harvesting from air-laden moisture has been a subject of great interest to address world-wide water shortage issues. Recently, it has been shown that tailoring surface wettability can enhance the moisture harvesting performance. However, depending on the harvesting condition, a different conclusion has often been reported and it remains unclear what type of surface wettability would be desirable for the efficient water harvesting under the given condition. Here we compare the water harvesting performance of the surfaces with various wettability under two different harvesting conditions–dewing and fogging, and show that the different harvesting efficiency of each surface under these two conditions can be understood by considering the relative importance of the water capturing and removal efficiency of the surface. At fogging, the moisture harvesting performance is determined by the water removal efficiency of the surface with the oil-infused surfaces exhibiting the best performance. Meanwhile, at dewing, both the water capturing and removal efficiency are crucial to the harvesting performance. And well-wetting surfaces with a lower barrier to nucleation of condensates exhibit a better harvesting performance due to the increasing importance of the water capture efficiency over the water removal efficiency at dewing.

INVESTIGATING THE PROBABILISTIC OPTIMIZATION OF POLLUTANT LOAD ALLOCATION IN THE UNDERGROUND WATER RESOURCES BY USING VIDEO METERS TECHNIQUE (CASE STUDY: WELL KNOWN AS GHADIM IN KERMAN)

Due to the importance of water in development and economic and social development of human society and the issue of water shortage, today, preservation of water resources is a crucial requirement of the country and given that climate and segmentation, many areas is a component of drylands and the most basic water supply, is underground water resources, so the groundwater vulnerability assessment plays a critical role in protecting and exploiting these resources. According to the above, the main issues in this study provide a solution for the maintenance and optimization of underground water resources and attempts to use the video meters technique, a good model to identify and contaminant load to the resources provided. This is despite the fact that all limiting factors such as distribution of water resources and integrated water and underground geothermal area has been studied and based on the results obtained, the optimal strategies for water resource and water resources in this study were similar and could create new space for the water sector decision-makers.

Integrated double mulching practices optimizes soil temperature and improves soil water utilization in arid environments.

Water shortage threatens agricultural sustainability in many arid and semiarid areas of the world. It is unknown whether improved water conservation practices can be developed to alleviate this issue while increasing crop productivity. In this study, we developed a "double mulching" system, i.e., plastic film coupled with straw mulch, integrated together with intensified strip intercropping. We determined (i) the responses of soil evaporation and moisture conservation to the integrated double mulching system and (ii) the change of soil temperature during key plant growth stages under the integrated systems. Experiments were carried out in northwest China in 2009 to 2011. Results show that wheat-maize strip intercropping in combination with plastic film and straw covering on the soil surface increased soil moisture (mm) by an average of 3.8% before sowing, 5.3% during the wheat and maize co-growth period, 4.4% after wheat harvest, and 4.9% after maize harvest, compared to conventional practice (control). The double mulching decreased total evapotranspiration of the two intercrops by an average of 4.6% (P<0.05), compared to control. An added feature was that the double mulching system decreased soil temperature in the top 10-cm depth by 1.26 to 1.31°C in the strips of the cool-season wheat, and by 1.31 to 1.51°C in the strips of the warm-season maize through the 2years. Soil temperature of maize strips higher as 1.25 to 1.94°C than that of wheat strips in the top 10-cm soil depth under intercropping with the double mulching system; especially higher as 1.58 to 2.11°C under intercropping with the conventional tillage; this allows the two intercrops to grow in a well "collaborative" status under the double mulching system during their co-growth period. The improvement of soil moisture and the optimization of soil temperature for the two intercrops allow us to conclude that wheat-maize intensification with the double mulching system can be used as an effective farming model in alleviating water shortage issues experiencing in water shortage areas.

Influences of microbial communities on groundwater component concentrations during managed artificial recharge

Managed aquifer recharge is one of the most popular methods for dealing with local water shortage issues, and the bacterial community could be a vital factor influencing groundwater quality during this process. In this study, analysis of variations in groundwater components during artificial recharge revealed three stages at a text site in China. During stage I, total iron and dissolved organic carbon levels are stable basically, dissolved oxygen and SO4 2− levels have rising trends, NO3 − curve varied not obviously. Variation curves show increases in dissolved oxygen, NO3 −, SO4 2− and stabilization in dissolved organic carbon and total iron at stage II. During stage III, dissolved oxygen and NO3 − have rising trends, dissolved organic carbon, total iron, and SO4 2− keep stable. At 25 and 70 days the Simpson and Shannon–Wiener indices show that microbial community richness and population diversity underwent a gradual dynamic change after recharge water arrived. Correlation analysis shows that the Simpson index was mainly affected by dissolved oxygen and NO3 −. PCR-DGGE confirmed these findings. Overall, the results revealed that the main bacterial communities reduce total nitrogen, total phosphorous, and chemical oxygen demand, which corresponded to the calculated correlation index.

Electrocoagulation for the Treatment of Oil Sands Tailings Water

Title: Electrocoagulation for the treatment of oil sands tailings water The Canadian oil sands industry has been receiving widespread International criticism on environmental issues, among which is its use of water resources. A major process to recover the valuable bitumen (a heavy, viscous form of petroleum) from the oil sands resource is surface mining. A by-product of mining operations is large volumes of toxic tailings water which are stored in large dykes, the infamous ‘tailings ponds’, covering a total area greater than 175 sq. km. These have led to significant environmental damage because of land displacement, the contamination of natural waters, and impact on wildlife such as waterfowl that land into the water surface. Large volumes of fresh water are withdrawn to make up for the water being stored as tailings water. On average about 3 barrels of fresh water are withdrawn per barrel of bitumen produced, the main source of fresh water being the Athabasca River. The local communities and stakeholders have expressed concerns about fresh water withdrawal rates, potentially creating water shortage issues. The nature of contaminants in tailings wastewaters makes the treatment processes costly in order to minimize environmental impact, hence the operators are forced to store the water as ponds. Tailings water is a complex mixture of contaminants, very fine clay particles that take decades to settle, toxic organic compounds such as naphthenic acids and polycyclic aromatic hydrocarbons (PAH’s), silica, and heavy metals including nickel, vanadium, arsenic and mercury. Since the start of mining operations in 1967, the oil sands industry is yet to implement a method to treat tailings water, alleviate the use of tailings ponds, and significantly increase recycle rates. Electrocoagulation (EC) is one technology that could address these issues. Prior research on various other wastewaters has shown that EC can remove several contaminants including fine suspended solids, toxic organic matter, silica, and heavy metals [1] which are the common contaminants in oil sands tailings water. In its simplest form, EC uses an electrochemical cell to generate coagulating agents in the wastewater by electrochemical reactions, resulting in flocculation of contaminated particles which separate out by settling or flotation. Currently, coagulation and flocculation of most industrial wastewaters are performed by the use of chemicals like metal salts. However, EC has many advantages over the chemical method. The electric field used in EC enhances the flocculation process by setting the charged colloidal particles in motion resulting in the coagulation of even very fine suspended solids [2]. This will be advantageous when applied to tailings water because the most difficult to remove contaminant it contains are the very fine, slow settling clay particles. In addition, EC simultaneously removes heavy metals by precipitation as the pH increases during the process. Furthermore, hydrogen gas bubbles generated at the cathode by water reduction reaction will float the flocculated particles to the water surface, thus providing better separation of contaminants. Another major advantage is that no chemicals are required, minimizing secondary pollution. The high conductivity of tailings water is an advantage, as it will provide low electrolytic solution resistance, leading to low energy requirement. Increased contaminants removal rates, the avoidance of chemical addition, and lower energy consumption suggest that EC could reduce the environmental impact and cost of water treatment for treating tailings water. The main research objectives are to investigate the effectiveness of EC for the treatment of tailings water and by removing several contaminants simultaneously. The potential to eliminate tailings ponds by using EC have been explored. Experiments with EC have been conducted on real industrial samples of tailings water and on synthetic wastewater samples prepared in the lab. Contaminant removals have been assessed by measuring various water quality parameters such as turbidity, total suspended solids, “Chemical Oxygen Demand (COD)” and “Total Organic Carbon (TOC)” both of which quantifies the amount of oil present, and the concentrations of heavy metals. Moreover, special attention has been given to the removal of fine particles by the use of water contaminated with fine kaolin clay, the most burdensome of all the contaminants. Also, the effect of different electrochemical reactor designs have been explored. The results are very promising, several contaminants are being removed simultaneously, with removal rates as high as 90%. The results gathered demonstrate that some of the different types of reactor designs tested not just improve contaminant removal rates but also reduce energy consumption significantly.

An overview on emerging water scarcity in Pakistan, its causes, impacts and remedial measures

Apparently with two thirds of the earth's surface covered by water, it is evidently clear that water is one of the most important elements responsible for life on earth. It is not only vital for sustenance of life, but equally essential for socio-economic development. Water is the unique gift of God and the basic requirement of life. Due to the high indulgence and exploitation of human being with nature, the global environment is changing every day. As a result the water resources are depleting gradually. The global fresh water shortage and food security issues related to the teeming billions of population necessitated the shifting of fresh water from agriculture to other more pressing uses. The country is facing the worst ever crises of water shortage for last many years, as water available for any given use has become increasingly scarce. The rapidly growing population, expanding of irrigation areas, and growing urban & Industrialization are putting more stresses on water resources. Therefore, building of more reservoirs and an effective management strategy are the needs of time. The problem of water shortage particular in Sindh is crucial as being the end user and lower riparian on the Indus basin irrigation system.

Multi-Objective Optimal Allocation for Regional Water and Land Resources

With rapid development of society and economy, the issue of water shortage has presently been more and more serious in China. Optimal water and land resources allocation, involving many aspects such as society, economy, ecology etc., is a rational approach to solve this problem. In this study, a substantially improved model, i.e., multi-objective optimal allocation, is established for coordinating the usage of water and land resources. The model was developed on the basis of Immune Genetic Algorithms (IGA), and it mainly includes three objectives and seven constraints. The results of case study show that there is no water shortage in the predicting year of 2020 in Dongtai City, Jiangsu Province by using the optimal allocation of water and land resources. The new optimal allocation proposed in this study has a positive influence to promote the economic and social harmonious development and the natural environment protection for coastal areas of China.

Optimal planning of water supply system for long-term sustainability

Developing a long-term system plan for sustainable water supply is a challenging task due to system complexity and future uncertainties in water demands and source availability. Here a coupled optimization model is proposed for water supply system design and long-term operations by deciding system component sizes and water flow allocations simultaneously. The objective is to minimize overall system costs (i.e., sum of capital and operation costs) while meeting water demands and operational constraints. The economic costs include initial component construction costs and operation expenditure over pre-defined operation years. The proposed model integrates a genetic algorithm with a linear programming model to optimize water infrastructure investments and annual water transfers satisfying flow constraints. The coupled model was applied to a simplified water supply network composed of multiple water sources and users. For the application network, various qualities of water from different sources could be supplied to different users. Plausible future scenarios with time varying water demands were simulated representing potential future conditions. Application results show that the proposed coupled model is beneficial in decision making process to design structural components in near future and prepare long-term policies for water shortage and water right issues in upcoming years. The model can be tailored to a specific system and various regulations and conditions can be incorporated within the model without adding complexity to the optimization framework.

Seawater desalination in China: Retrospect and prospect

China has been and will be facing water shortage issues due to the disparity between water supply and demand, especially within Chinese coastal areas. Seawater desalination can increase the total water supply and is an important component in addressing water shortage issues in China. With the development of the last six decades, seawater desalination technologies and applications have been advanced remarkably. Total seawater desalination capacity has increased from 10,000m3/d in 2000 to approximately 660,000m3/d in 2011. Seawater desalination has been primarily used in power generation, steel manufacturing, petrochemical industry, and public water supply. 75 desalination plants have been constructed in China, among which 16 desalination plants have capacities of 10,000m3/d or more. Nine desalination plants are under construction, which will provide capacity of 408,000m3/d. Most of the desalination applications (99.5% of the desalination capacity) are located within five provinces: Liaoning, Shandong, Hebei, Tianjin, and Zhejiang. The dominant desalination technologies are reverse osmosis (RO) and multi-effect distillation (MED). 80.3% of desalination plants employ RO and 14.5% of desalination plants adopt MED. The desalination capacities of RO and MED are 348,000 and 232,000m3/d, respectively. Facing the challenge of water shortage, seawater desalination is of necessity in China and is increasingly an inevitable national strategy to address the issue. China is one of the most promising market for seawater desalination. However, international desalination companies will still dominate seawater desalination market for the foreseeable future.

A Novel Electrochemical Membrane Bioreactor as a Potential Net Energy Producer for Sustainable Wastewater Treatment

One possible way to address both water and energy shortage issues, the two of major global challenges, is to recover energy and water resource from wastewater. Herein, a novel electrochemical membrane bioreactor (EMBR) was developed to recover energy from wastewater and meantime harvest clean water for reuse. With the help of the microorganisms in the biocatalysis and biodegradation process, net electricity could be recovered from a low-strength synthetic wastewater after estimating total energy consumption of this system. In addition, high-quality clean water was obtained for reuse. The results clearly demonstrate that, under the optimized operating conditions, it is possible to recover net energy from wastewater, while at the same time to harvest high-quality effluent for reuse with this novel wastewater treatment system.

A monitoring of environmental effects from household greywater reuse for garden irrigation

The option of reusing greywater is proving to be increasingly attractive to address the water shortage issue in many arid and semiarid countries. Greywater represents a constant resource, since an approximately constant amount of greywater is generated from kitchen, laundries, bathroom in every household daily, independent of the weather. However, the use of greywater for irrigation in particular for household gardening may pose major hazards that have not been studied thoroughly. In this study, a 1-year monitoring was conducted in four selected households in Perth, Western Australia. The aim of the monitoring works is to investigate the variability in the greywater flow and quality, and to understand its impact in the surrounding environments. Case studies were selected based on different family structure including number, ages of the occupants, and greywater system they used. Samples of greywater effluent (showers, laundries, bathtub, and sinks), leachate, soil, and plants at each case study were collected between October 2008 and December 2009 which covered the high (spring/summer) and low (autumn/winter) production of greywater. Physical and chemical tests were based on the literature and expected components of laundry and bathroom greywater particularly on greywater components likely to have detrimental impacts on soils, plants, and other water bodies. Monitoring results showed the greywater quality values for BOD, TSS, and pH which sometimes fell outside the range as stipulated in the guidelines. The soil analyses results showed that salinity, SAR, and the organic content of the soil increased as a function of time and affected the plant growth. Nutrient leaching or losses from soil irrigated with greywater shows the movement of nutrients and the sole impact from greywater in uncontrolled plots in case studies is difficult to predicted due to the influence of land dynamics and activities. Investigative and research monitoring was used to understand greywater irrigation in households. Greywater quality is very site specific and difficult to predetermine or control except for the use of some recommended household products when using greywater. Investigative and research monitoring was indicated that greywater quality is very site specific and difficult to predetermine or control except for the use of some recommended household products when using greywater.

Anaerobic co-digestion of source segregated brown water (feces-without-urine) and food waste: For Singapore context

The objective of this study was to evaluate the feasibility of anaerobic co-digestion of brown water (BW) [feces-without-urine] and food waste (FW) in decentralized, source-separation-based sanitation concept. An effort has been made to separate the yellow water (urine) and brown water from the source (using no-mix toilet) primarily to facilitate further treatment, resource recovery and utilization. Batch assay analytical results indicated that anaerobic co-digestion [BW+FW] showed higher methane yield (0.54–0.59L CH4/gVSadded) than BW or FW as a sole substrate. Anaerobic co-digestion was performed in the semi-continuously fed laboratory scale reactors viz. two-phase continuous stirred-tank reactor (CSTR) and single-stage sequencing-batch operational mode reactor (SeqBR). Initial 120d of operation shows that SeqBR performed better in terms of organic matter removal and maximum methane production. At steady-state, CODs, CODt, VS removals of 92.0±3.0, 76.7±5.1 and 75.7±6.6% were achieved for SeqBR at 16d HRT, respectively. This corresponds to an OLR of 2–3gCOD/Ld and methane yield of about 0.41L CH4/gVSadded. Good buffering capacity did not lead to accumulation of VFA, showing better process stability of SeqBR at higher loading rates. The positive findings show the great potential of applying anaerobic co-digestion of BW+FW for energy production and waste management. In addition, daily flush water consumption is reduced up to 80%. Decentralized, source-separation-based sanitation concept is expected to provide a practical solution for those countries experiencing rapid urbanization and water shortage issues, for instance Singapore.

Dynamic Planning of Water Resource and Electric Power Systems under Uncertainty

AbstractHydropower plays an important role in electric power systems. It not only interacts with many non-hydropower generation activities but also competes with other water users (industrial, commercial, residential, and agricultural) for limited water resources. Therefore, the objective of this study is to investigate an optimized water allocation scheme within a water resource and electric power management system through developing an inexact water resource and electric power systems planning model (WPEM). WPEM is based on the interval-parameter programming and mixed-integer programming techniques; thus, it can deal with dynamics of capacity expansion and uncertainties associated with system management. The developed method is then applied to a power system with water shortage issues in the future. The results of scenario analysis indicate that WPEM could help get insights into the tradeoff between system benefit and water utilization as well as that between system benefit and environmental concern. Th...

Water Consumption Reduction by Application of Treated Hygienic Sewage of Yazd Combined Fuel Power Plant to Irrigate the Green Space, Iran

Recently, attention has been given to water shortage in Iran; especially in areas such as the province of Yazd, which has arid and semi-arid climate and is located in the central plateaus of Iran. In these situations, re-using sewage is one of the ways we can overcome the problem of water shortage. In order to combat the issue of water shortage and protect the environment, the Yazd combined cycle power plant has applied the effluent of the hygienic sewage treatment system (the active sludge system with extended aeration modification) for irrigation, which is the aim of this study. Studies show that every worker of this power plant uses 85 liter of water and produces 30 liter of hygienic sewage in every work shift. According to experiments that have been carried out on samples of raw sewage, pH, BOD5, COD and TSS were found in 6.9 , 306.45mg/l, 595.85mg/l, 376.35mg/l, respectively. The amounts of the same parameters were 7, 65.80mg/l, 139.1mg/l, 34mg/l in the samples exiting treatment system, which are in accordance with Iran Department of Environment standards and with the irrigation criteria either. The system efficiency in eliminating some parameters is as follows, 76 % COD, 78% BOD5 and 90 % of TSS. The most important effluent parameters in respect to irrigation water standards are SAR, Cl¯ and EC that have been measured in 6.15meq/l, 10meq/l and 1.882 µ mohs/cm, respectively. Based on comparisons between these amounts and the Wilcox diagram, the treated sewage is categorized as medium according to the quality of water used for irrigation. So it has been used to irrigate the green space within the ambit of the Yazd combined cycle power plant.

Facilitating Collaborative Efforts to Redesign Community Managed Water Systems

The Upper Taieri River catchment is an arid area in the Otago region of the South Island of New Zealand faced with intensifying agriculture production. This article describes an assessment of the education/communication processes of a water resource management project and the effects on farmer beliefs/attitudes and targeted outcomes. Lessons learned from this project will guide future activities in the catchment and may have wider significance in developing community-determined allocation and management regimes in other areas faced with water shortage and water quality issues.

Reuse feasibility of pre-treated grey water and domestic wastewater with a compact household reverse osmosis system

Many countries in the Mediterranean basin are facing water shortage issues. Since water is becoming a rare resource, grey water and domestic wastewater reuse arises as a sustainable solution to reduce the overall water demand. In this study, a compact household reverse osmosis unit was used in order to determine the feasibility of pre-treated grey water and domestic wastewater reuse. The preliminary studies revealed that the compact system used was able to treat the wastewaters studied with quite high organic matter and nutrient removal efficiencies. For pre-treated grey water, the COD and BOD removal rates were around 80%. For pre-treated domestic wastewater, the organic matter removal rates were higher. In addition, soluble nutrients, such as nitrate and phosphate were also studied. The conductivity of permeate was reduced to 15 mS/cm and 55 mS/cm for grey water and domestic wastewater, respectively, within 15 min. The permeate obtained was free of suspended solids and had an excellent physical appearan...

Multi-scale variability and trends of precipitation in North China

The issue of water shortage and related eco-environmental degradation in North China is one of the major emerging problems in China. Precipitation is the most key factor for water resources. Based on the historical flood/dryness grade dataset during the period of 1470–2000 obtained from 25 gauging stations in North China, the multi-scale variability and trends are analyzed by means of power spectral and continuous wavelet transform. It is found that the precipitation is characterized by obvious seasonal changes, quasi biennial oscillations, inter-annual 4–7 year component and inter-decadal 19-year periodicity. The MK test results showe that step changes occurred around 1914 and 1964 in the annual precipitation. As for the historical flood/dryness grade time series, it is characterized by 4∼5 year ENSO mode inter-annual oscillation, quasi-10 year inter-decadal variability, quasi-24 year component and 50–80 year centurial periodicity. However, the scales of these variations have decreased significantly since the 1970s. The trend for precipitation change in North China has been negative for last 30 years. Further research shows that North China will continue to become dryer until 2015 and may change to a wetter regime after 2020. These findings should be helpful for future decision-making to ensure sustainable water resource management in North China.