A Fact Sheet from the Navy on a Cost-Effective and Environmentally Acceptable Process to Treat Sodium Nitrite Wastewater Generated from Marine Steam Boiler Maintenance Operations
Sodium Nitrite (NaNO2) Wastewater Treatment
T. Richard Lee, Ph.D.
(805) 982-1670
DSN 551-1670
Pollution Prevention Technology Development Branch
Pollution Prevention Division
Naval Facilities Engineering Service Center
Port Hueneme, CA
Objective
To Develop a Cost-Effective and Environmentally Acceptable Process to Treat Sodium Nitrite Wastewater Generated from Marine Steam Boiler Maintenance Operations:
- Hydroblast Cleaning
- Hydro Static Pressure Testing
- Lay-up &
- Rinsing
Customers: NSYs, SIMAs, NSs & Naval Surface Force
Why Navy?
- Navy Uses Sodium Nitrite Solutions (1200 ppm-NaNO2) as a Rust-preventing fluid in Marine Steam Boiler Maintenance Operations
- Navy Generates about 10 Million Gallons of Sodium Nitrite Wastewater Annually
- NPDES Prohibits the Discharge of Nitrite at levels greater than 1 mg/L to Surface Water
- Disposal Cost by Contractors Ranges from $2.50/gal to $3.50/gal
- No Proven Technology Available for Total Conversion of Nitrite to Nitrogen Gas
Benefits
- Denitrification Process Converts Nitrite Directly to Diatomic Nitrogen Gas and Removes Heavy Metals/Sludge before Discharging to a Sewer
- Reduce Disposal Cost by 95% (from $3.50/gal to $0.15/gal)
- Over $8 Million Annual Savings for NSYs and $17 Million Annual Savings for Navy-Wide Boiler Maintenance Operations
Approach
Completed Bench-Scale Test
100-gallon Capacity
NCEL TN: N-1841
Completed Pilot Plant Test at LBNSY
500-gallon Capacity
Contractor Report
Completed Operational Scale Process Design
600-gallon Transportable
Operational Scale System Fabrication
Field Demonstration and Tech Transfer
Process Block Flow Diagram for the Nitrite Reduction/Metal Precipitation System
See source document.
Sulfamic Acid Reduction Process
See source document.
Figure 3-11. Run 3-1 Nitrate/Nitrile Nitrogen vs Time - See source document.
Run Number: 3-1
sulfamic Acid Addition Time (Hrs): 5
% of Theoretical Sulfamic Acid Addition: 102
Wastewater Batch Volume (L): 1550
N03/N02-N
(Average of On-site and Off-Site Results)
Influent Concentration (mg/L): 150
Effluent Concentration (mg/L): 14
Percent Removal: 91
N02-N: (Off-Site Laboratory Results)
Influent Concentration (mg/L): 130
Effluent Concentration (mg/L): ND
Percent Removal: 100
Sulfamic Acid Parameters:
Feed Concentration (g/L): 50
Volume Added (L): 35
Flow Rate (L/hr): 7
Implementation Plan
Transfer Technology to NAVSSES of NAVSEA for full Implementation of this Process Navy-wide.
Department of the Navy
Naval Surface Warfare Center
Carderock Division
Reply Refer to
9221
Ser 9222/206
Aug 25, 1994
From: Commander, Carderock Division, Naval Surface Warfare Center, Philadelphia, PA 19112-5083
To: Commanding Officer, Naval Facilities Engineering Service Center (ESC-421), Port Hueneme, CA
Subj: WASTEWATER DENITRIFICAITON UNIT
Ref: (a) MTG btwn NFESC (R. Lee)/CDNSWC (J. McGillian, A. Schoepflin) of 11 Aug 94
- During reference (a), Carderock Division, Naval Surface Warfare Center (CDNSWC) discussed their capability in providing support for testing and fleetwide implementation of a Denitrification System. Naval Facilities Engineering Service Center (NFESC) representative Dr. R. Lee expressed interest in our capabilities and requested a tasking letter be prepared addressing CDNSWC support during the initial prototype unit construction and testing.
- CDNSWC proposed support is outlined below:
Task
- Provide on-site equipment inspection and engineering support for initial unit testing - Funding Req'd-4K
- Review operation and maintenance manual and provide comments and concerns - Funding Req'd-2K
- Provide general engineering and equipment support - Funding Req'd-2K
Total 8K
- The following are some additional items that CDNSWC can support if requested during initial development:
- Develop preliminary Allowance Parts List (APL) data for spare parts-Funding Req'd-4K
- Develop Maintenance Requirement Cards (MRC) needed for the system-Funding Req'd-2K
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Last Updated: January 25, 1996