Brackish Water Pretreatment

    Develop and demonstrate a low-cost, energy efficient, simple and reliable system for use in brackish water pretreatment for electrodialysis reversal (EDR) and reverse osmosis (RO).

Background

    The option for inland desalinization for the supply of fresh water is becoming increasingly important in regions where there are not enough natural water resources available.  This issue is specifically critical in arid and semi-arid areas where the natural water resources are not sufficient to meet the population growth, economic development and agricultural needs. Electrodialysis reversal and reverse osmosis systems show potential; however, pretreatment of brackish water would greatly enhance the ability of these systems to remove particulates and troublesome inorganic foulants.

Problem Statement

    Develop and demonstrate a low-cost, energy efficient, simple and reliable system for use in brackish water pretreatment for electrodialysis reversal (EDR) and reverse osmosis (RO). The proposed solution would remove particulates, aluminum, manganese, and iron to specified levels using commercially available, cross over or new innovative technologies but must be applicable for use at the Tularosa Basin desalination facility located at Alamogordo NM. The solution must respect the specified EDR and RO feed water requirements.

Design Considerations

Your proposed solution should:

• Meet state and federal regulations;

• Be reasonably easy to use and reliable;

• Be applicable to rural systems;

• Be affordable, maintainable, and cost effective;

• Provide optimum performance, viable yield, and minimum reject water; 

• Be energy efficient;

• Address disposal of concentrates and provide a viable disposal pathway; and

• Be adaptable to different size systems.

Evaluation Criteria

    Each team is advised to read the Participation Guide for a comprehensive understanding of the contest evaluation criteria.  Upon your registration, WERC will provide you with a copy of the Public Involvement Plan and Participation Guide.  Additionally, your proposed design will be evaluated on issues identified in the problem statement as well as others listed below.

• Ease of use;

• Affordability;

• Yield and viability;

• Reliability;

• Energy and water use efficiency;

• Cost effective operation;

• Disposal cost and handling;

• Long term performance and system management;

• Cost and quality of the water produced per liter;

• Functionality and operability throughout the year; and

• Concentrate, reject water management and waste generation.

Bench-Scale Demonstration

    During the contest, WERC will provide you with up to five gallons of a sample consistent with typical brackish water containing various amounts of particulates, salts, etc.  The specific amount required for your process to operate during the bench scale must be communicated to WERC at least three weeks prior to the contest.  Appropriate Material Safety Data Sheets should be available during the bench scale demonstration. The initial (there may be more samples taken in the near future - check this page at least once a month until January 2009 for updates on the water chemistry) water quality follows:        

Written Report Requirements

    The written report is the best means to demonstrate your team’s insight into the problem. The report should discuss other technologies considered but not pursued and why and to give the reader full understanding of the magnitude of your team’s involvement with the problem details.  The report will be evaluated for clarity, logic and coherence.  Standards appropriate for publications in technical journals apply.

    In addition to the listed requirements, the following must be discussed in your report to WERC management:

• Describe process steps in detail including cost/benefit, evaluation criteria, and screening protocol;

• Discuss advantages, disadvantages, and limitations of the selected method;

• Include recent references and sources of information;

• Address any safety issues or considerations associated with the process;

• Discuss the time-line for system construction until full operation;

• Present a sensitivity analysis regarding the selected process;

• Discuss total life-cycle costs costs for both EDR and RO cases; and

• Waste generation, concentrate management, and handling.

For More Information

Contact:
Barbara Valdez, Program Facilitator
(575) 646-7821
(800) 523-5996