can desalinated water be used for agriculture



The wastewater generated from desalination can be reused for agricultural irrigation, after proper treatment. However, advanced technology like membrane based desalination may lead to higher quality water and minimal health and environmental risks.Nov 24, 2017

What are the advantages of desalinated water for agriculture?

 · Desalination for agriculture has advantages as it utilizes non-conventional and unlimited water resources which do not depend on the weather, increases agricultural productivity and product quality, reduces water consumption and has a less negative impact on soils and crops in comparison with direct use of seawater or brackish water.

Which countries use the most desalinated water for agriculture?

Desalinated water is of high quality and can have less negative impact on soils and crops in comparison with direct use of brackish water. For cost considerations, brackish water desalination is more suitable for agricultural production than is seawater desalination.

What technology is used for desalination in agriculture?

 · Agricultural desalination produces a potentially inexhaustible water supply that is not dependent on precipitation. It can increase the productivity and quality of agricultural products, consume less surface and groundwater, and allow for the recovery of salty soils. However, there are also challenges to using desalinated water for agriculture.

Why can’t plants use desalinated water?

13 hours ago · Although desalination is commonly believed to be too expensive for agriculture, Spain is disproving the notion. Spain has made a success of desalination, even for agricultural irrigation, des… Desalination and Agriculture: Lessons From Spain | … Air & Climate Drinking Water Environmental Management Health & Safety Monitoring & Testing


Can you grow crops with desalinated water?

Desalinated Water Can Harm Crops, Researchers Warn.

Can salt water be desalinated and used for irrigation?

Saltwater (especially sea water) is desalinated to produce water suitable for human consumption or irrigation. The by-product of the desalination process is brine.

What can desalinated water be used for?

Desalinated seawater is produced primarily for municipal/potable use and for agricultural irrigation but is also used extensively in many other applications where high quality water is required.

What are the disadvantages of desalinated water?

List of Cons of DesalinationIts plants are expensive to build. … It can be a very costly process. … It requires a lot of energy to process. … It contributes to the world’s greenhouse gas emissions. … Its resulting brine can have a dramatic environmental impact. … It might risk producing contaminated water.

Can ocean water be used for irrigation?

Using seawater for irrigation is a possible solution; however, because it is saline, it is not without problems. Plant roots can absorb the water when it is moderately saline, but they have to work hard to do so. If the water is too saline, water will move out of the plants to the soils.

How efficient are desalination plants?

The efficiency of seawater desalination plants is low, 10–25% as compared with the efficiency of other major industrial plants [7]. For example, the efficiency of cogeneration power generating plants is 50%. The efficiency of small desalination plants such as used on ships is in the low range.

What are the three main problems with desalination?

Desalination has the potential to increase fossil fuel dependence, increase greenhouse gas emissions, and exacerbate climate change if renewable energy sources are not used for freshwater production.

Are desalination plants sustainable?

Desalination is key to providing fresh water to millions of people around the world. Yet, it can harm marine wildlife, takes a lot of energy, and it’s often not sustainable.

What are the pros and cons of desalination plants?

Advantages & Disadvantages of Desalination PlantsAdvantage: Provides Accessible Drinking Water. … Disadvantage: High Costs to Build and Operate. … Advantage: Quality and Habitat Protection. … Disadvantage: Environmental Impact.

Why is desalination not widely used?

It is exorbitantly expensive, requires large amounts of energy, it is environmentally damaging plus it is only really viable for coastal communities.

Why are there no desalination plants?

There is increasing regional scarcity, though. So why don’t we desalinate more to alleviate shortages and growing water conflicts? The problem is that the desalination of water requires a lot of energy. Salt dissolves very easily in water, forming strong chemical bonds, and those bonds are difficult to break.

What are the disadvantages of having to rely on a desalination plant?

Desalination is not a perfected technology, and desalinated water can be harmful to human health as well. By-products of the chemicals used in desalination can get through into the “pure” water and endanger the people who drink it. Desalinated water can also be acidic to both pipes and digestive systems.

How do you remove salt from irrigation water?

Salt accumulation Salts are supplied to soil by irrigation water, geologic sources (soil parent material), fertilizers, manures, composts, or any other amendment. Salts are removed by leaching and crop removal. When irrigation water is high in salt, leaching is the only effective way to remove salt.

How can we use saline water in agriculture?

Saline agriculture is a possible solution: food is produced on salt-affected soils and/or using salt or brackish water for irrigation water. The latter strategy also saves fresh water, which is a scarce resource on this planet, and even more so in those areas generally affected by salinization.

Is hard water suitable for irrigation?

Without treatment, irrigation using hard water delivers calcium carbonate to the crop in its calcite state which can form a coating on the roots and the leaves, like putting a coating of sunscreen on plant. This prohibits the plant from receiving the maximum benefit from the water, minerals, fertilizers and pesticides.

What is the process of water desalination?

Desalination uses reverse osmosis technology to separate water molecules from seawater. Water from the ocean is forced through thousands of tightly-wrapped, semipermeable membranes under very high pressure. The membranes allow the smaller water molecules to pass through, leaving salt and other impurities behind.


How does desalination help agriculture?

Desalination is a technical option to increase the availability of freshwater both in coastal areas with limited resources and in areas where brackish waters – such as saline groundwater, drainage water and treated wastewater – are available. Desalinated water can also be crucial in emergency situations where water sources have been polluted by saline incursions. However, desalinated water produced worldwide, estimated at 7 500 million m3/annum, equals only 0.2 percent of total water use.

Where is desalination technology used?

The experts covered the areas in the world where water desalination technology has been implemented, namely: the United States of America, North Africa, the Near East countries (especially the Persian Gulf countries), and Spain, where desalinated water is also applied in agriculture in addition to drinking supply. The experts who attended the consultation were:

What are the environmental problems of desalination?

A major environmental problem of water desalination is the production of a flow of brine containing the salts removed from the intake water and that needs to be disposed. In addition, this brine may be polluted. This brine represents a significant fraction of the intake water flow. Seawater desalination typically yields a brine flow of 50–65 percent of the intake water flow, with about twice the initial concentration (FAO, 2003a). Brackish water desalination may result in 10–50 percent of reject water, and its salt concentration is dependent on the initial concentration of the brackish water and the number of stages in the process. Thus, brine production poses a significant problem of environmentally safe waste disposal. Even where plants are near the sea, brine disposal may affect the local marine ecosystem. Environmentally safe disposal depends mainly on the site of the treatment plant. With plants situated near the sea or close to brackish environments, such as estuaries, brine disposal is comparatively easier than that from inland desalinating facilities. Where plants are not far from the sea, the construction of special collectors is an option. However, in this case, the additional environmental costs increase the total cost significantly. In inland plants, one option is to inject the brine into a confined aquifer through deep wells. This alternative has serious technical problems and high environmental risks.

How is desalination made?

The first desalination technology to be developed was thermal distillation. In this process, saline water is distilled into steam, which in turn is condensed into pure water. Later, membrane processes, such as electro-dialysis (ED) and reverse osmosis (RO), were developed. In an ED process, salts are separated from water by means of an electric load application. In RO, pressure is applied to the intake water to force it to flow through a semi-permeable membrane that prevents most of the salts from passing through. The higher the salt concentration of the intake water is, the higher the pressure that is required. The pressure required for desalinating brackish waters range from 100 to 270 kPa, while that required for seawater ranges from 550 to 1 000 kPa (FAO, 2003a). Solar energy may also be used to produce water vapour, which is then condensed on a cooler surface to form the desalinated water. However, this process produces only a small amount of water and is generally ignored as a technological solution. The high-energy requirement is an essential feature of the desalination process. Table 1 (based on data in FAO, 2003a) describes some characteristics of different desalination technologies and their corresponding energy requirements. Semiat (2000) provides more detailed information on desalination technologies, while Furukawa (1997) provides information on RO. In order to select the appropriate desalination technology for each specific use, it is necessary to consider site-specific factors, such as the intake water composition, the

What are some ways to increase freshwater resources?

Among the options for augmenting freshwater resources is the desalination of salty groundwater, brackish drainage water and seawater. Distilling drinking-water from seawater has been studied over many centuries by Mediterranean and Near East civilizations. Large-scale solar ponding to serve as domestic drinking-water was practised more than 100 years ago in Egypt (Abu Zeid, 2000). However, progress on modern desalination was made during the 1960s and plants have been developed since the 1970s, starting with some countries of the Persian Gulf because of their ready availability of energy and relevant scarcity of freshwater resources. Intensive research for large-scale commercial desalinating technologies began in the United States of America in the early 1960s (Buros, 1999). The objective of this paper is to give an overview of desalination technologies, their energy requirements and costs, as well as of the achievements, constraints and perspectives of desalination.

Is desalination a private sector?

Progress has been made towards private- sector participation and investment with guarantees from the government in most instances for desalination for drinking-water supplies. Because of the single-buyer’s market for drinking-water, the risk is perceived to be lower than for agricultural markets. The various contract models are evolving from build own or build own operate transfer (BOOT), etc. However, institutional issues remain an impediment as the process requires a policy framework. The experts recommended design build operate (DBO) as a new contractual model with many of its associated advantages, in particular, in relieving capital burden, transferring construction and operational risk to the private sector, and attracting innovations. Furthermore, the experts recommended better regulation and legislation for brackish groundwater in aquifers as discrepancies exist in property rights (in some countries, they are considered public, in others, private). The recommendation is extended to overall groundwater management, which needs better legal definition and understanding.

What is the theme 3 of the Water Desalination?


How can desalination help agriculture?

The desalination technologies for agricultural irrigation play a major role in satisfying growing water demands in water scarce regions. Due to stringent ionic concentration standards for agricultural irrigation water, desalination for agriculture is more energy demanding and additional post-treatment is requisite. Reverse osmosis (RO) has emerged as an efficient technology, but the burning of fossil fuels to fulfil the energy requirements is becoming expensive and emission of greenhouse gases is recognized as harmful to the environment. Thus, efforts should be directed towards cost reduction by integrating renewable energy resources into the process. Many of the bench and pilot scale trials like integrated RO with low energy such as forward osmosis (FO), nanofiltration (NF), microfiltration (MF) and solar energy revealed significant improvements in cost savings. However, all these modern technologies have their own problems which can be overcome by further research and development. This paper aims to review the main benefits and constraints associated with desalination technologies for agriculture. The available water resources, the desired qualities of water for agriculture and the challenges and future of desalination in agriculture are discussed.

How does desalination affect irrigation?

While desalination has positive effects on the potential irrigation water quantity and quality, the technique may also be a considered potential source of groundwater pollution. The present study investigated the effects of desalination wastewater discharge on groundwater quality in an arid area in southern Iran for the 2012-2017 period. The chemical composition of the groundwater samples was evaluated considering pH, EC, Na + , Ca 2+ , Mg 2+ , SO 4 2+ , Cl − , and HCO 3 −. The suitability of groundwater for drinking and irrigation purposes as well as spatial pattern of groundwater pollution was analyzed. The results showed that mean concentration of Na + , Ca 2+ , Mg 2+ , SO 4 2− , and Cl − in all investigated wells increased from 148, 94, 46, 247, and 257 mg/L in 2012 to 282, 146, 71, 319, and 582 mg/L in 2017, respectively. Using Gibb’s diagram, it was shown that the groundwater quality is slightly alkaline and primarily controlled by evaporation. Based on our findings, about 78% of the study aquifer displayed groundwater with good to excellent water quality that can be used for drinking and irrigation purposes. However, the eastern part of the aquifer was classified as unsuitable for use due to the disposal of desalination plant wastewater. The spatial distribution of WQI and other indices such as SAR, TDS, and TH showed that groundwater in the eastern part of the aquifer has deteriorated since the establishment of the desalination plants. To reverse this trend, it is important to implement regulations against waste-water discharge from desalination plants.

Is irrigation in Tunisia a problem?

Irrigation in Tunisia is threatened all over the country . The irrigated coastal area of Dyiar-Al-Hujjej has observed a drop in agricultural activity following a seawater intrusion. Thus, yields have become disrupted in direct relation to the quantities of fresh water supplied and transferred over a distance of 100 km. For the sustainability of this area, the feasibility of using desalinated water to stabilize the irrigation water supply was analyzed. When all crop water requirements are to be met with desalinated water, the net income is negative for crops currently grown, except strawberry. All the open-field crops remain unprofitable even in the case of agro-industrial development, except tomatoes. A blending between desalinated seawater and aquifer saltwater also leads to a negative income for the main crops. The introduction of greenhouses to replace the same open-season crops is beneficial when desalinated water is used. The use of desalinated water in irrigation faces the high cost of desalination (0.5 US $/m3) while the average price of irrigation water in Tunisia is 0.05 US $/m3. Desalination can be recommended only in the case of crops with low need for water and high added value.

Is desalinated water safe?

Desalinated water is not suitable for direct use as it is prone to corrosion and has adverse effects on human health and the environment. Desalinated water is slightly acidic, lacks minerals and cannot be used un-buffered, thus making remineralization an important component downstream of desalination. We systematically review remineralization requirements and regulations with respect to corrosion control, human health and agriculture needs. This includes not only concentrations of specific ions, but also relative ratios. We compare and contrast existing remineralization methods with emerging, energy-efficient methods that require less chemicals. The impact of the lack of certain minerals such as magnesium, calcium and sulfate, on health and environment are evaluated in order to guide regulatory bodies towards maintaining safe standards. Emerging methods include harvesting minerals from seawater or brine through the combination of nanofiltration membranes with others (CIX, UF, Diananofiltration) and using them to re-mineralize the product stream. This reduces the need for chemicals from an external source and thus lowers the environmental impact. This review is to be used as a tool for guiding readers in proper remineralization choices depending on their application.

How much water is produced from desalination?

Currently, the world produces more than 100 billion liters (about 27 billion gallons) a day of water from desalination, which leaves a similar volume of concentrated brine.

Who is the director of Abdul Latif Jameel Water and Food Systems Lab?

Lienhard is the Jameel Professor of Water and Food and the director of the Abdul Latif Jameel Water and Food Systems Lab. “The desalination industry itself uses quite a lot of it,” Kumar says of sodium hydroxide. “They’re buying it, spending money on it.

How is brine converted into useful products?

The method of converting the brine into useful products uses well-known and standard chemical processes, including initial nanofiltration to remove undesirable compounds, followed by one or more electrodialysis stages to produce the desired end product.

How is brine disposed of?

But it leaves behind as a waste product a lot of highly concentrated brine, which is usually disposed of by dumping it back into the sea, a process that requires costly pumping systems and that must be managed carefully to prevent damage to marine ecosystems. Now, engineers at MIT say they have found a better way.

Can waste be converted into chemicals?

Now, engineers at MIT say they have found a better way. In a new study, they show that through a fairly simple process the waste material can be converted into useful chemicals — including ones that can make the desalination process itself more efficient.

Where is desalinated water used?

Desalinated water is being used for irrigation purposes in many places around the world, where the available water source is too saline to be used. Such water sources may include groundwater, sea water and sometimes surface water from lakes.

What is desalination in water?

Desalination is a water treatment process in which salts are removed from water. There are various methods of desalination, of which, the main method used today is Reverse Osmosis.

Does desalination remove carbonate?

Desalination also removes carbonate hardness from water. This results in water that has a lower resistance to changes in pH. Adding even a small amount of acid to the desalinated water might result in a sharp drop of its pH. Therefore, in such cases, the water has to be stabilized by adding sources of bicarbonate, such as potassium bicarbonate.

Does reverse osmosis remove salts?

Although there is some selectivity to specific ions, desalination with reverse osmosis removes most salts from the water and the amount of salts removed depends mostly on the pressure and on the ratio between the amount of desalinated water produced and the amount of brine water rejected and discharged as waste.

Is saline water toxic to plants?

High concentrations of specific ions in the saline water may be toxic to the plant.

Is salinity a problem for agriculture?

Water salinity is a major problem for agriculture. Saline water contains high concentrations of salts, which crops might not tolerate.

Can desalinated water be mixed with untreated water?

Desalinated water can be mixed with untreated water.

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