Desalination techniques — A review of the opportunities for desalination in agriculture
Introduction
Population growth, food security concerns, climate change impacts on agriculture, freshwater resource overuse and land degradation worldwide are forcing international scientific communities to look for alternative approaches to our current resource management approach for agricultural purposes. This includes all aspects associated with water resources and their availability to support ever-growing demands for both agricultural and potable water demands. Desalination technologies may provide one opportunity for generating cost-effective and potentially climate-independent water resources of controlled quality for agriculture applications.
As shown in Fig. 1, seawater desalination is the most used solution to address water shortage especially for potable water applications. In this respect the number of desalination plants around the world, both planned and under construction, has increased significantly in recent years, as shown in Fig. 2, especially in Australia where they have been targeted for providing additional sources of potable water [25]. It is estimated that about 69% of available water resources around the world are used for irrigation [110] and as water demands increase the number of desalination plants for irrigation for agriculture has also increased. Consequently there is increased emphasis on enabling cost effective desalination technologies to provide water of suitable quantity and quality for agricultural applications.
Drier countries such as Australia and Spain have a long history with desalination technologies. In the past, the high capital and operating costs of desalination and the energy required have been major constraints to large-scale production of freshwater from brackish waters and seawater. However, desalinated water is becoming more competitive for urban use because desalinating costs are declining associated with increasing demand from population growth and reduced security of supply from surface water and usable groundwater and it is expected that these increases in efficiency will flow through to the agricultural sector. However, in spite of these developments, currently the cost of desalinated water is still too high for the use of this resource in broad-scale irrigated agriculture. An exception appears to be intensive horticulture for high-value cash crops, such as vegetables and flowers (mainly in greenhouses) grown in coastal areas where safe disposal of brines is easier than in inland areas [11]. For example Sundrop farms (Sundrop-Farms, Personal communication), uses 860,000 m3 of fresh water yearly to irrigate 2000 m2 of greenhouses. If the costs for providing desalinated water continue to reduce, its use is expected to become more viable because desalination for agricultural purposes has a number of significant advantages including:
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Tailored conductivity for irrigation water
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Assured supply
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Enables agricultural products of consistent quality
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Production may be increased compared to other water sources.
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The water may attain a higher resale price due to quality and supply assurance.
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It allows recovery of saline soils by irrigation with high quality water.
Section snippets
Integrated water and food production: desalination and agriculture
Desalination allows a widening in utilisation of available water resources by producing freshwater from saline or brackish natural water sources. Over the past decade conventional water production costs have been rising in many parts of the world and costs for desalination have been declining, consequently desalination has become more economically attractive and competitive. Lattemann et al. [58] estimated that by 2015 the costs of freshwater treatment, wastewater reuse and desalination are
Desalination technologies
There are a significant number of technologies available for desalination of both sea and brackish water supplies. Many of these are commercial, however; there are some that are either approaching commercialisation or are at an advanced stage of development such as membrane distillation; which are not assessed in this analysis. The choice of technology is influenced by the source water quality, energy demand, and most importantly the value placed upon the recovered water. For example the
Other techniques applicable to desalination for agricultural purposes
There are a number of other commercial techniques available that may potentially be suitable for providing desalinated water for agricultural purposes depending on the specific location and water needs. These techniques include multistage flash distillation (MSF), multi effect distillation (MED), capacitive deionization (CDI), vapour compression (VC) and solar humidification and dehumidification (HDH). Emerging technologies which may one day be suitable for providing desalinated water include
Feedwater quality
A summary of the processes for treating a range of feedwater salinities is summarised in Table 3. For low salinity brackish waters of salinity up to 2500–3000 mg/L the processes that are in commercial scale use and that are the most economic for that salt concentration are RO, NF, ED, IX and HDH. RO and ED both have large-scale plants up to hundreds of ML/day capacity running. The rest have smaller but well-tested plants operating and CDI has a 1 ML/day plant at the commercial stage. Distillation
Discussion
Opportunities for applying desalination technologies to agriculture go hand-in-hand with requirements to improve irrigation practices and efficiency, which can achieve significant reductions in water demand and therefore make the application of desalinated technologies more viable, because the cost of the water is not as critical a component.
Gregory [118] summarised the challenges and opportunities in water-use efficiency in irrigated agriculture as “Irrigated crops occupy about 15–20% of the
Conclusions
Suitable technologies such as reverse osmosis and electrodialysis to provide desalinated water for agriculture are currently available and can provide water for agriculture, but at a cost that is currently more expensive than that generally used for agricultural purposes. The adaptation of desalination to supply water for agriculture may be cost effective; especially when applied to high value crops where the cost of the water is not a critical issue. For these applications established
Acknowledgements
The support of the National Centre of Excellence for Desalination and the CSIRO Water for a Healthy Country Flagship is gratefully acknowledged.
References (118)
- et al.
Performance analysis of photovoltaic electrodialysis desalination plant at Tanote in Thar desert
Desalination
(1987) An innovative reverse osmosis desalination system using hydrostatic pressure
Desalination
(2006)Water desalination by solar powered electrodialysis process
Renew. Energy
(2003)- et al.
Solar desalination with humidification–dehumidification cycle: review of economics
Desalination
(2006) - et al.
Membrane distillation: a comprehensive review
Desalination
(2012) - et al.
A review of organic polymeric membranes for the dehydration of aqueous ethanol by pervaporation
Chem. Eng. Process. Process Intensif.
(2011) - et al.
Water desalination by humidification and dehumidification of air: state of the art
Desalination
(2001) - et al.
Application of nanofiltration for reuse of municipal wastewater and quality analysis of product water
Desalination
(2013) - et al.
Membrane distillation for water desalination: how to choose an appropriate membrane?
Desalination
(2003) - et al.
Forward osmosis: principles, applications and recent developments
J. Membr. Sci.
(2006)
NF membrane characteristics and evaluation for sea water processing applications
Desalination
Economical study of a small-scale direct contact humidification–dehumidification desalination plant
Desalination
Desalination of water by reverse osmosis using gravitational potential energy and wind energy
Desalination
PV and thermally driven small-scale, stand-alone solar desalination systems with very low maintenance needs
Desalination
Feasibility study on wind-powered desalination
Desalination
Technical review and evaluation of the economics of water desalination: current and future challenges for better water supply sustainability
Desalination
A feasibility study of municipal wastewater desalination using electrodialysis reversal to provide recycled water for horticultural irrigation
Desalination
Combining reverse osmosis and pulsed electrical current electrodialysis for improved recovery of dissolved organic matter from seawater
J. Membr. Sci.
An electrodialysis sea water desalination system powered by photovoltaic cells
Desalination
Sustainable water for the future: water recycling versus desalination chapter 2 global desalination situation
Sustain. Water Future
Desalination process using super hydrophilic nanoparticles via forward osmosis integrated with ultrafiltration regeneration
Desalination
Combining reverse osmosis and ion exchange
Filtr. Sep.
Assessing the economic feasibility of regional deep saline aquifer CO2 injection and storage: a geomechanics-based workflow applied to the Rose Run sandstone in Eastern Ohio, USA
Int. J. Greenh. Gas Control
Energy requirements of ammonia-carbon dioxide forward osmosis desalination
Desalination
Using capacitive deionisation for inland brackish groundwater desalination in a remote location
Desalination
Submarine seawater reverse osmosis desalination system
Desalination
A novel low energy fertilizer driven forward osmosis desalination for direct fertigation: evaluating the performance of fertilizer draw solutions
J. Membr. Sci.
Forward osmosis desalination of brackish groundwater: meeting water quality requirements for fertigation by integrating nanofiltration
J. Membr. Sci.
Submarine and underground reverse osmosis schemes for energy-efficient seawater desalination
Desalination
Overview of the cost of desalinated water and costing methodologies
Desalination
Technical evaluation of stand-alone solar powered membrane distillation systems
Desalination
Economic evaluation of stand-alone solar powered membrane distillation systems
Desalination
Electrodialysis, a mature technology with a multitude of new applications
Desalination
A photovoltaic-powered seawater reverse-osmosis system without batteries
Desalination
La desalación en España
Sostenibilidad para zonas vulnerables (Desalination in Spain. Sustainability for vulnerable areas)
Introduction to Desalination Technologies in Australia
RO brine treatment and disposal methods
Desalin. Water Treat.
Factors Affecting Natural Organic Matter Removal (NOM) and Scaling Fouling in NF
The potential of renewable energies in Sicily for water desalination applications
Water desalination for agricultural applications
Solar-powered desalination by membrane distillation
Proc. IDA World Congress, Abu Dhabi
Wastewater Treatment by Ion Exchange
Membrane distillation — a low energy desalting technique?
Water
MIEX® DOC process launched in Western Australia
Water J.
A solar desalination system using the membrane distillation process
Technical Brochure No. 46
An Overview of Solar Desalination for Domestic and Agriculture Water Needs in Remote Arid Areas
Continuous ionic filtration
Greenhouse-power plant hybrid set to make Jordan's desert bloom
Science
Water, Chapter 7
9th Congreso nacional de medio ambiente (9th National Environment Congress)
Nuevas fuentes de agua (New Water Sources)
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