PINK WATER TREATMENT TECHNOLOGY RESEARCH
 |
|
||||||||||||
| Overview: | The thermophilic biological
process (TBP) is used to treat pink water, which is explosive-laden wastewater
originating from two munition functions: load, assemble, and pack (LAP)
and demilitarization (DEMIL). TBP utilizes granular activated carbon (GAC)
to adsorb the explosives from the wastewater, followed by base hydrolysis
and thermophilic (microbiological) regeneration of the GAC. The treated
wastewater is sent to a wastewater treatment plant. Although additional
research is required, the TBP process potentially could be adapted to treat
explosives-contaminated groundwater and soils.
TBP is a modification of the Army's present method of GAC regeneration. Currently, Army Ammunition Plants (AAPs) meet pink water discharge requirements by removing the contaminants using GAC adsorption systems. The explosive-laden GAC is either regenerated for reuse or incinerated for disposal. Under the present method, regeneration often does not achieve Army requirements, and the GAC must be disposed as a hazardous waste. The process begins with the pink water flowing into the GAC adsorption system. The explosive contaminants are first adsorbed onto the GAC, which has demonstrated a high affinity and capacity for these nitrobody compounds. After an adsorption cycle, flow through the GAC column stops and recirculation of a regeneration solution starts. The GAC column is first heated to 80°C (176°F) for base (caustic) hydrolysis, and then cooled to 55°C (131°F) for thermophilic regeneration, inoculated with explosives-degrading organisms, and aerated. The column becomes a bioreactor. Thus, explosive compounds, concentrated by the previous adsorption step, are depleted, and the GAC in the column is regenerated. The bioreactor fluid, containing natural organisms and enzyme systems, passes to the industrial wastewater treatment plant. In the last step, the regenerated GAC column cools and is placed on stand-by. A TBP pilot-scale plant was installed and operated at the Milan AAP (MLAAP), Milan, Tennessee, prior to being transitioned to the Iowa AAP (IAAAP), Middletown, Iowa, in February 2001. This plant is capable of processing 1.5-2.0 gallons per minute. The TBP skid equipment is self-contained, and consists of three GAC columns, a regeneration tank, pumps, air compressor, a chemical injection system, and instrumentation/controls. Five confirmatory tests were completed at the MLAAP. Through this demonstration project, the following conclusions were reached:
Using spent GAC provided by IAAAP, a loading and regenerating cycle of three (3) more tests was complete in March 2001. The results showed a Destruction and Removal Efficiency (DRE) of explosives from the GAC surface of 99.2, 98.4, and 99.2 percent in the three tests, respectively. |
|||||||||||||||||||||||||||||||||||||||||||||||||||||
| Compliance Benefit: | Pink water by definition
is a Resource Conservation Recovery Act (RCRA) K047 Hazardous Waste due
to the presence of nitrobodies, including 2,4,6 trinitrotoluene (TNT), cyclotrimethylene-trinitramine
(RDX), and cyclotetramethylene-tetranitramine (HMX). The exact composition
of pink water is highly variable and dependent on process materials and
operations. The maximum concentration of dissolved energetic-related pollutants,
in pink water, is 200 parts per million. Statutes also mandate that pink
water be treated prior to disposal.
The U.S. Army required a DRE rate of 80-90 percent or higher. The DRE is the difference in the amount of nitrobodies on the GAC, before and after regeneration, and is reported as a percentage of the total loading of nitrobodies on the GAC. The TBP achieved DRE rates of greater than 90 percent under optimum operating conditions. The Compliance Benefits listed here are only meant to be used as a general guideline and are not meant to be strictly interpreted. Actual Compliance Benefits will vary depending on the factors involved, e.g., the amount of workload involved. |
|||||||||||||||||||||||||||||||||||||||||||||||||||||
| Materials Compatibility: | No materials compatibility issues were identified. |
|||||||||||||||||||||||||||||||||||||||||||||||||||||
| Safety and Health: | The technology itself poses
no safety or health risks. However, several contaminants in the pink water
are dangerous, and precautions should be taken. Proper personal protective
equipment is recommended. The personnel in work areas should wear safety
glasses with side-shields and steel-toed safety shoes. Hands should be protected
with nitrile (rubber) gloves when loading the column with pink water and
when handling the microorganisms. Good hygiene (e.g., washing hands with
antibacterial liquid soap after handling the microorganisms) and daily housekeeping
should be practiced. Neither respirators nor special ventilation are required.
Consult your local industrial health specialist and your local health and safety personnel prior to implementing this technology. |
|||||||||||||||||||||||||||||||||||||||||||||||||||||
| Benefits: |
|
|||||||||||||||||||||||||||||||||||||||||||||||||||||
| Disadvantages: |
|
|||||||||||||||||||||||||||||||||||||||||||||||||||||
| Economic Analysis: | The following cost elements
compare the use of a conventional GAC adsorption system using GAC once with
a TBP that regenerates the GAC five times. |
|||||||||||||||||||||||||||||||||||||||||||||||||||||
| Assumptions: |
Table 1. Annual Operating Costs for Pink Water Treatment Technologies
|
|||||||||||||||||||||||||||||||||||||||||||||||||||||
| Capital Cost: | The capital cost to retrofit
the TBP technology to an existing 20-gpm system is approximately $230,560.
|
|||||||||||||||||||||||||||||||||||||||||||||||||||||
| Operational Cost: | Operating costs for GAC TBP
will vary considerable depending upon the process configuration required
for the particular GAC regeneration application. Annual operating costs
for the field-level GAC TBP system were estimated at $49,285, versus $131,950
per year for a conventional GAC process.
|
|||||||||||||||||||||||||||||||||||||||||||||||||||||
| Payback Period: | The calculated payback period
for investment in the equipment/process is 3.44 years, using a 15-year analysis,
10% discount rate, and a straight line depreciation over a period of 10
years. |
|||||||||||||||||||||||||||||||||||||||||||||||||||||
| Annual Savings: | The calculated annual saving
is $82,665 in operating costs, if the TBP is retrofitted to an existing
20-gpm GAC adsorption system.
|
|||||||||||||||||||||||||||||||||||||||||||||||||||||
| Economic Analysis Summary: |
A summary of the financial implications for retrofitting a GAC TBP system on a conventional GAC process in field-level activities, which includes annual operating cost benefit and capital investment required, is shown in Table 2. The 15-year NPV and IRR, as well as the payback period are also listed in Table 2. Table 2: Financial Implications of Retrofitting a Conventional GAC Process with a GAC TBP
|
|||||||||||||||||||||||||||||||||||||||||||||||||||||
| NSNs: | None Identified. |
|||||||||||||||||||||||||||||||||||||||||||||||||||||
| Approving Authority: | Approval is controlled locally,
and the technology should be implemented only after engineering approval
has been granted. Major claimant approval is not required. |
|||||||||||||||||||||||||||||||||||||||||||||||||||||
| Points of Contact: | Dr. Mahmood A. Qazi,
Concurrent Technologies Corporation, 100 CTC Drive, Johnstown, PA
15904, Phone: (814) 269-2726 |
|||||||||||||||||||||||||||||||||||||||||||||||||||||
| Vendors: |
CTC is the sole source of the Thermophilic
Biological Process (TBP) Technology. This is a complete list, as there are no other suppliers of this type of equipment.
|
|||||||||||||||||||||||||||||||||||||||||||||||||||||
| Source(s): | Concurrent Technologies Corporation. Pilot-Scale Thermophilic (Biological) Process Final Technical Report. June 15, 2000. | |||||||||||||||||||||||||||||||||||||||||||||||||||||
| Supplement(s) to the Data Sheet: |
|
|||||||||||||||||||||||||||||||||||||||||||||||||||||
[Back]
