Task 5: Removal of Carbamazepine from Wastewater

Task Sponsor:  USDA Arid Lands Agricultural Research Center

Background Information

Carbamazepine (CBZ) is an antiepileptic pharmaceutical which has continued to accumulate in surface water and ground water all over the world. Most wastewater and sewage treatment plants fail to eliminate over 90% of the carbamazepine from the influent arriving at these plants. The long term effects of ingesting these trace amounts of CBZ through treated wastewater are currently unknown. However, the anthropogenic impact is clearly evident in the aquatic and agricultural environments. The widespread reach of this contaminant deems it necessary for remote areas to have access to a water treatment system capable of reducing the concentration of the carbamazepine to less than 1 part per billion. The average human comes in contact with 25 gallons of water per day through drinking, brushing, hand washing, food cleaning, etc. Extrapolated to a 4 person household and this water treatment system must be capable of treating 100 gallons each day.

Problem Statement

Each team in this task will design and manufacture a wastewater treatment system for use in individual home settings. These systems must be capable of outputting while consuming no more energy than 1 kWh per day. The treated water must have a carbamazepine concentration of 1 ppb or less. 

Source-water characteristics

Dissolved organic carbon concentration 25 ppm (sucrose as carbon source)

1 ppm carbamazepine (5H-Dibenz[b,f]azepine-5-carboxamide; CAS #298-48-4)

Design Considerations

  • Any treatment system (e.g. physical, biological, chemical) will be considered, however, the resulting water must be safe for human consumption and use no more than 1 kWh to treat 100 gallons of water.
  • Maximum energy consumption 1 kWh (typical daily output from a single solar panel)
  • Treat 100 gallons per day (water with direct or indirect human contact)
  • If the design uses sorption then the energy to create (if consumable) or regenerate (if reusable) the sorbate must be included in the 1 kWh maximum energy consumption.
  • If the design uses chemical treatment then the energy to create (if consumed) or regenerate (if reusable) the reactant must be included in the 1 kWh maximum energy consumption.
  • If biological treatment is used the product water must be disinfected.

The following method can be used to test treated water:

  • Solid phase extraction using Oasis HLB (Waters Co., Milford, MA).
  • Precondition with 5 mL MTBE, followed by 5 mL MeOH, and 5 mL of water
  • Air-dry for 5 min
  • Load cartridges with 1 L of treated water
  • Air-dry for 5 min
  • Elute using two successive 2-mL aliquots of MTBE
  • Evaporate sample to <0.25 mL
  • Bring to 1 mL with acetonitrile
  • Analyze using HPLC-MS (transition 237.1 (m/z) → 194.06 (m/z))

The final concentration of Carbamazepine should be <= 1 ppb.

Bench-Scale Demonstration

During the bench-scale demonstration, your team should plan to present a functional bench-scale model that clearly conveys the proposed solution.  Your team should develop, demonstrate and present a complete package that includes technical performance as well as financial, regulatory, and safety information. Sample will be taken for testing. Samples must be made available with enough time for the testing to take place prior to the conclusion of the contest.

Written Report Requirements

The written report should demonstrate your team’s insight into the full scope of the issue that you have chosen and include all aspects of the problem and your proposed solution. The report will be evaluated for quality of writing, organization, clarity, reason, and coherence. Standards for publications in technical journals apply.  In addition to the listed requirements, your report must address in detail the items highlighted in the Problem Statement, Design Considerations, and Evaluation Criteria.

Evaluation Criteria

Your proposed design will be evaluated on the following:

  • Technical fundamentals, performance, safety and other issues stated in the problem statement
  • Potential for real-life implementation
  • Comprehensiveness of performance metrics
  • Thoroughness and quality of the business plan and economic analysis
  • Originality, innovation, functionality, ease of use, maintainability, reliability, and affordability of the proposed technology
  • Sample will be taken and tested for Carbamazepine removal