Desalination A National Perspective (2008) / Chapter Skim
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8 A Strategic Research Agenda for Desalination
8 A Strategic Research Agenda for Desalination
Pages 212-232
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From page 212... ...
Over the past 50 years the state of desalination technology has advanced substantially, and improvements in energy recovery and declining membrane material costs have made brackish water and seawater desalination a more reasonable option for some communities. However, desalination remains a higher-cost alternative for water supply in many communities, and concerns about potential environmental impacts continue to limit the application of desalination technology in the United States.
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From page 213... ...
Understand the environmental impacts of desalination and develop approaches to minimize these impacts relative to other water supply alternatives, and 2. Develop approaches to lower the financial costs of desalination so that it is an attractive option relative to other alternatives in locations where traditional sources of water are inadequate.
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From page 214... ...
STRATEGIC DESALINATION RESEARCH AGENDA The committee identified research topics as part of a strategic agenda to address the two long-term research goals articulated earlier. This agenda is driven by determination of what is necessary to make desalination a competitive option among other water supply alternatives.
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From page 215... ...
Develop hybrid desalination processes to increase recovery 7. Improve existing desalination approaches to reduce primary energy use a.
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From page 216... ...
The possible environmental impacts of concentrate management approaches range from effects on aquatic life in surface water discharges to the contamination of drinking water aquifers in poorly designed injection wells or ponds. Both site-specific studies and broad analyses of relative impacts would help communities weigh the alternatives for meeting water supply needs.
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From page 217... ...
Planners would benefit from clear guidance on appropriate monitoring and assessment protocols. Environmental data should be collected for at least 1 year in the area of the proposed facility before a desalination plant with surface water concentrate discharge comes online so that sufficient baseline data on the ecosystem are available with which to compare postoperating conditions.
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From page 218... ...
2 Develop improved intake methods at coastal facilities to minimize impingement of larger organisms and entrainment of smaller ones Although intake and screen technology is rapidly developing, continued research and development is needed in the area of seawater intakes to develop cost-effective approaches that minimize the impacts of impingement and entrainment for coastal desalination facilities. Current technology development has focused on subsurface intakes and advanced screens or curtains, and these recent developments should be assessed to determine the costs and benefits of the various approaches.
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From page 219... ...
simply shows depth to saline water. Newer and better solute chemistry data collected over the past 40 years exist in the files of private, state, and federal offices but are not generally organized for use in brackish water resources investigations.
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From page 220... ...
5. Improve pretreatment for membrane desalination Pretreatment is necessary to remove potential foulants from the source water, thereby ensuring sustainable operation of the RO membranes at high product water flux and salt rejection.
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From page 221... ...
6. Improve membrane system performance Sustainable operation of the RO membranes at the designed product water flux and salt rejection is a key to the reduction of desalination process costs.
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From page 222... ...
The duration of equipment life in a desalination plant directly relates to the total costs of the project. Saline and brackish water plants are considered to be a corrosive environment due to the high levels of salts in the raw water.
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From page 223... ...
6e. Develop hybrid desalination processes to increase recovery.
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From page 224... ...
Renewable energy sources could help mitigate future increases in energy costs by providing a means to stabilize energy costs for desalination facilities while also reducing the environmental impacts of water production. Research is needed to optimize the potential for coupling various renewable energy applications with desalination.
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From page 225... ...
For coastal concentrate management, research is needed to develop improved diffuser technologies and subsurface injection approaches and to examine their costs and benefits relative to current disposal alternatives. The high cost of inland concentrate management inhibits inland brackish water desalination.
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From page 226... ...
IMPLEMENTING THE RESEARCH AGENDA In the previous section, the committee proposed a broad research agenda that, if implemented, should improve the capacity of desalination to meet future water needs in the United States by further examining and addressing its environmental impacts and reducing its costs relative to other water supply alternatives. Implementing this agenda requires federal leadership, but its success depends on participation from a range of entities, including federal, state, and local governments, nonprofit or
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From page 227... ...
The research needed to support the attainment of Goal 2 includes several topics that are clearly in the federal interest, as defined earlier. These include efforts to reduce prime energy use, to integrate renewable energy resources within the total energy picture and increase reliance upon them, and to understand the impacts of energy pricing on the future of desalination (see highlighted topics in Box 8-1)
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From page 228... ...
To ensure that future federal investments in desalination research are integrated and prioritized so as to address the two major goals identified in this report, the federal government will need to develop a coordinated strategic plan that utilizes the recommendations of this report as a basis. It is beyond the committee's scope to recommend specific plans for improving coordination among the many federal agencies that support desalination research.
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From page 229... ...
Therefore, a well-developed and clearly articulated strategic research plan, as called for above, should be a precondition for any new federal appropriations. Initial federal appropriations on the order of recent spending on desalination research (total appropriations of about $25 million annually, as in fiscal years 2005 and 2006)
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From page 230... ...
The majority of the federal funding directed toward Goal 2 should support projects that are in the public interest and would not otherwise be privately funded (see Box 8-1) , such as some high-risk and long-term research initiatives (e.g., developing novel desalination processes that sharply reduce the primary energy use)
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From page 231... ...
CONCLUSIONS AND RECOMMENDATIONS A strategic national research agenda has been conceived that centers around two overarching strategic goals for further research in desalination: (1) to understand the environmental impacts of desalination and develop approaches to minimize these impacts relative to other water supply alternatives and (2)
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From page 232... ...
This environmental research includes work to understand environmental impacts of desalination intakes and concentrate management, the development of improved intake methods to minimize impingement and entrainment, and cost-effective concentrate management technologies. Research funding in support of reducing the costs of desalination (Goal 2)
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