PHYTOREMEDIATION OF EXPLOSIVES IN GROUND WATER AT THE MILAN ARMY AMMUNITION PLANT USING INNOVATIVE WETLANDS-BASED TREATMENT TECHNOLOGIES
|F.J. Sikora, L.L. Behrends, H.S. Coonrod, and W.D. Phillips, Tennessee Valley Authority, Environmental Research Center P.O. Box 1010, Muscle Shoals, AL, USA 35662, and D.F. Bader, U.S. Army Environmental Center, Environmental Technology Division Aberdeen Proving Ground, Maryland 21010-540l||
Many army ammunition plants across the country have problems with ground water contaminated with explosives. A field demonstration was initiated at the Milan Army Ammunition Plant near Milan, Tennessee early in 1996 to demonstrate the feasibility of treating contaminated ground water with constructed wetlands. Two different systems were designed and installed.
A lagoon system consists of two cells in series with each cell having dimensions of 24 x 9.4 x 0.6 m (L x W x H). A gravel-bed system consists of three gravel-beds operated in series with a primary anaerobic cell having dimensions of 32 x 11 x 1.4 m (L x W x H), followed by a pair of secondary cells each with dimensions of 5.5 x 11 x 1.4 m (L x W x H). The primary cell is maintained anaerobic by adding powdered milk to the water every two weeks.
The secondary cells are maintained aerobic via reciprocation, whereby water is pumped back and forth from one cell to another to cause a recurrent fill and drain action. The lagoons were planted with sago pond weed, water stargrass, elodea, and parrot feather. The gravel-bed wetlands were planted with canary grass, wool grass, sweet flag, and parrot feather. Water began flowing to each of the wetland treatment systems at 19 L min-1 starting in June 1996.
The design hydraulic retention time through each treatment system is 10 days. Influent and effluent water samples are being collected every 2 weeks. Intensive sampling of water interior to the wetlands is occurring every 2 months. Influent concentrations of trinitrotoluene (TNT), cyclotrimethylenetrinitramine (RDX), and cyclotetramethylenetetranitramine (HMX) were approximately 3, 3, and 0.2 mg L-l, respectively.
Both the lagoon and gravel-bed wetlands are reducing TNT below O.002 mg L-l. The gravel-bed wetland is removing RDX and HMX in the ground water, whereas the lagoon wetland is not as effective with removal efficiencies of only 47 and 20%, respectively. The presentation will include a discussion of wetland operation and data collected. Information from the demonstration will be used to recommend design and operational parameters for implementing the technology to other sites.
Key words: explosives, constructed wetlands, demonstration
Return to Main Table of Contents
Sub-Menu of Event Programs
Sub-Menu of Event Programs
Send comments on the Great Plains/Rocky Mountain HSRC web pages to: firstname.lastname@example.org;
comments or questions about this WWW server, to: email@example.com.