1. Ammonium Perchlorate Treatment Technology Development
James A. Hurley
AFRL/MLQE
Tyndall AFB, FL
Overview of AFRL/MLQE research and engineering development efforts regarding treatment technology for ammonium perchlorate contaminated water.
Requirements, deficiencies, and current events mandating technology development.
Lessons learned from fundamental discoveries and engineering practice which posture MLQE for addressing new engineering challenges associated with low-concentration perchlorate contamination.

2. Ammonium Perchlorate - A National Technical Asset Integral to Strategic Defense Systems - ICBM, SLBM, NRO
Ammonium perchlorate is the primary oxidizer in all solid propellants used in our strategic national defense systems; including inter-continental and submarine-launched ballistic missiles as well as delivery systems for NRO assets.
Ammonium perchlorate is a national technical asset.

3. Peace Keeper 1st Stage (98,000 lb)
Requirement
Increased Demand for Open-Burn/ Open-Detonation (OB/OD) Facilities with Large-Rocket Motor Capacity.
START II
Nunn-Luger
Non-Proliferation Treaty
Multi-National Force Reduction Treaty
Decreased Availability of OB/OD Facilities.
Clean Air Act Amendment (CAAA)
Base Realignment and Closure (BRAC)
Statement of Operational Need (SON )
Joint Logistics Commanders
Gen McDonald- AFLC/CC
During the 1980’s, a number of strategic arms agreements were put into effect which significantly increased the requirement to demilitarize large rocket motors (144 million pounds of propellant) from excess strategic assets.
This placed increased demand on open-burn/open-detonation facilities which has been the only means of large-rocket motor disposal.
At the same time, regulations and other events have reduced the capacity and availability of OB/OD facilities.
General McDonald and the Joint Logistics Commanders promulgated a Statement of Operational Need (SON ) to develop environmentally acceptable alternative technologies for open-burning and open-detonation.
Peace Keeper 1st Stage (98,000 lb)

4. High-Pressure Water Washout of Solid Propellant
Our approach begins with high-pressure water washout of the solid propellant. The bulk propellant is then macerated, the ammonium perchlorate dissolved in heated water, and separated from the propellant binder.

5. Perchlorate Recovery Process
Dilute Perchlorate
Concentrated
Perchlorate
H2O
Perchlorate
Concentrator
Mixed
Waste
Storage
Tank AP
Storage
Tank
NaOH
KP Filter
Press
Ion
Exchange
Potassium
Perchlorate
Reactor
Ammonium perchlorate is then concentrated by crystallization, centrifuged, and collected as AP or reacted with potassium salts to form potassium perchlorate (low-solubility) which is then collected from a filter press operation. To date, over 500,000 pounds of AP has been processed.
The high-value ammonium perchlorate and potassium perchlorate are reused in propellant or explosives formulations.
As much as 95% of the process water is recycled using ion exchange resin to recover high-concentration perchlorate salts. The effluent contains residual perchlorate and salts from resin regeneration which must be treated prior to discharge.
A process for treating this effluent was necessary to ensure a closed loop system and compliance with state discharge permits.
Effluent
Discharge Limits:
ClO4 < 10 ppm
TDS < 3800
KCl
KP Product
Higher ClO4 and TDS Increases Ion Exchange Column Regenerations,
More Regenerations Increase Total Dissolved Solids (TDS)

6. Wolinella succinogenes HAP-1
In 1989 a consortium of organisms was discovered which demonstrated an ability to degrade perchlorate to chloride. The bacterium responsible for the perchlorate reduction was isolated and identified as Wolinella succinogenes HAP-1.

7. Bench-Scale Reactor System
A bench-scale process was developed to answer performance questions necessary for engineering a reactor system. From fourteen months of operation we were able to ascertain the metabolic mechanism for perchlorate reduction, determine operating limitations, improve reaction efficiency, and select an optimum nutrient source.

8. Production-Scale AP Reactor System
From the results of our bench-scale work we engineered, designed and fabricated a pilot-scale system with 100x the capacity of the bench-scale system.
The purpose of the pilot-scale system was to answer the engineering questions necessary for developing a production-scale system for implementation.
This is a photograph of the pilot-scale AP Bioreactor System operated at Tyndall AFB. This system provided verification of engineering scaling factors, process performance parameters, process control parameters, system operability, non-steady-state operating characteristics, and preliminary capital and operating cost data.

9. Ammonium Perchlorate Biodegradation Process
Reactor 1
Reactor 2
AP Storage
Tanks
Nutrient
Feed
Tank
Water
Caustic
Acid
Programmable
Logic
Controller
Clarifier
The engineering data obtained from the operation of the pilot-scale system resulted in the design and fabrication of a production-scale (5000 gal/day) reactor system for implementation at a rocket motor manufacturing facility located in Utah (Thiokol Corporation, Brigham City).
The production-scale system has been successfully integrated with the Perchlorate Recovery Process and the Industrial Wastewater Treatment Plant which together handle all waste propellant and AP contaminated wastewater for the entire Thiokol facility.
The Thiokol Plant produces solid rocket motors for Minuteman, Castor, Titan, and Space Shuttle.
Dry
Yeast
Recycle
On-line
Perchlorate
Analysis
Reactors
Interim
Effluent
Storage
Nutrient
Mix
Tank
Dry
Nutrient
Feeder
Storage
To Sewage Treatment

10. Effect of Perchlorate Concentration on Capacity
Series
Operation
Parallel
Operation
The Thiokol system was designed for flexibility of operation by using a dual-reactor concept in which the reactors could be configured for parallel operation or series operation.
This configuration allows the treatment of high-concentration (to 10,000 ppm) low-flow perchlorate wastewater or low-concentration (>500 ppm) high-flow perchlorate wastewater.
This flexibility is important for achieving optimal operation of the perchlorate recovery process

11. Building at Thiokol Housing the Ammonium Perchlorate Bioreactor System

12. Primary and Secondary Ammonium Perchlorate Reactors

13. Metabolic Pathway for Energy Production in Wolinella succinogenes HAP1
chloride
ClO4-
ClO3-
ClO2-
Cl-
perchlorate
chlorate
chlorite
Concurrent with engineering a production-scale reactor system, research was conducted to better understand the process by which HAP1 metabolizes perchlorate.
Understanding the metabolic process ensures a robust, predictable, and controllable process for industrial applications.
It was discovered that HAP1 produces unique enzymes responsible for the reduction of perchlorate to chlorate, chlorate to chlorite, and finally chlorite to chloride. The first two steps provide energy to the organism for growth and reproduction followed by a detoxification step which eliminates waste products.
This knowledge presents opportunities to refine and adapt reactor systems which are more efficient and cost effective as well as applicable to a wider range of engineering challenges.
H2O
H2O
2 H2O 1

14. AP Treatment Technology vs Process Requirement
Under Development
Implemented
Implemented
Catalytic (enzyme) Reactor System
Multi-Stage AP Bioreactor
Perchlorate Recovery and Reuse
MLQE with industry partners have implemented cost-effective process solutions for treating high-concentration and moderate-concentration ammonium perchlorate contaminated wastewater.
The lessons learned and engineering experience gained from the development and implementation of the Perchlorate Recovery Process and the AP Bioreactor System postures MLQE to address the next engineering challenge that of treating low-concentration perchlorate water.
Multi-Stage AP Bioreactor with Ion Exchange
10 ppb - 10,000 ppb
Drinking Water, Ground Water
Low Concentration
,000 ppm
Production Waste Water
Moderate Concentration
1-20 wt. %
Bulk Propellant
High Concentration
Perchlorate Concentration [ClO4-]

15. Low-Concentration AP, High-Volume Wastewater Treatment
Two Approaches
New (or Improved) Unit Operations Enabling Utilization of Demonstrated Moderate-Concentration AP Water Treatment
Reverse Osmosis
Limited Capacity
Requires Effluent Reconditioning
Capacitive Deionization
Small Electrochemical Driving Force Limits Capacity
Ion Exchange
Resin Regeneration Very Difficult
Efficacy Uncertain at ppb Concentration Level
Selectivity Difficult
May Require Effluent Reconditioning
There are two general approaches to solving the low-concentration perchlorate water challenges. The first involves the development of new unit operations that concentrate perchlorate which enable the use of already demonstrated processes for treatment. There are technology barriers as well as implementation limitations associated with this approach.

16. Low-Concentration AP, High-Volume Wastewater Treatment (cont.)
New Process for Treating Low-Concentration AP Water Directly
Conventional Catalytic Reactor System
Non-Selective
Mass-Transfer Limited
Unknown Kinetics, Unknown Efficacy
Enzyme Catalytic Reactor System
Anion Specific Selectivity
High Capacity
Wide Application Range
Affect of Other Contaminants Unknown
Requires Multi-Disciplinary Effort
System Sustainability Uncertain
The second approach involves the development of new treatment processes which treat low-concentration perchlorate water directly. There are also technical barriers associated with this approach
However, the successful development and implementation of a new process technology may well provide a cost effective solution to a wide range of perchlorate treatment requirements.

17. One such approach under development involves an enzyme reactor concept.
The elucidation of a stepwise reduction of perchlorate to chloride by distinct microbial enzymes poses an opportunity to develop a multi-stage reactor configuration without the limitations of a biological reactor system.
By isolating and artificially producing selective enzymes in large quantities, an enzyme catalyzed reactor system could be constructed without the mass transfer limitations of cell membranes.
In addition, the enzymes are strictly selective for the desired anion species without the same limitations as a living biological systems to accomplish perchlorate conversion; I.e., perchlorate concentration, temperature, pH or requirement for the addition of nutrients and reagents.
Such a reactor system would be simpler, cheaper, more robust, and have a much wider range of application.

18. Air Force Benefit
The payoff to the Air Force from this continued effort is reduction of weapon system operational cost as well as ensured continued sustainability.
Manufacturing and maintenance facilities are under ever increasing constraints regarding the life-cycle management of materials used in weapon systems and their manufacture.
Technology insertion opportunities are made possible by the continued participation of MLQ in Air Force unique materials selection, development, and management through the weapon system life-cycle.

19. Points-of-Contact
James A. Hurley, Program Manager Air Force Research Laboratory MLQE 139 Barnes Drive, Suite 2 Tyndall AFB, FL (850) (voice) (850) (fax) Stan Rising Air Force Research Laboratory MLQE 139 Barnes Drive, Suite 2 Tyndall AFB, FL (850) (850) (fax)