NITREX™
NITROGEN REMOVAL WASTEWATER TREATMENT SYSTEM

Contact: Pio Lombardo, P.E.
Lombardo Associates, Inc.
Environmental Engineers/Consultants
188 Church Street
Newton, MA 02458
Tel: 617-964-2924
Fax: 617-332-5477
Email: Pio@LombardoAssociates.com

Technology Description:

Based on ten years of research, a proprietary patented nitrate-reactive media has been discovered that converts nitrate to inert nitrogen gas (denitrification). The NITREX™ reactive media is contained in a prefabricated tank or, for larger installations, in an engineered excavation. Nitrate contaminated wastewater is gravitationally fed through the treatment module. For septic tank applications, an oxidative pre-treatment step is required to convert ammonium (NH4+) to nitrate (NO3-) before the NITREX™ filter can perform the reductive denitrification step. Pre-treatment can be achieved with any of the existing oxidative technologies commonly used in wastewater treatment. The nitrate-free effluent from the NITREX TM filter is simply discharged to a conventional tile bed or receiving water body. Compared to other technologies, the NITREX™ filter is passive and essentially maintenance free. It provides almost 100% nitrate removal in a low cost easy to install process.

Application:

The NITREX™ filter can be used to remove nitrogen in water or wastewater such as treatment plants wastewater, septic tank effluent, agricultural runoff, and landfill leachate. For large flows, the NITREX™ reactive media may be placed in a lined excavation, and the wastewater allowed to gravitationally percolate through the reactive media.

Environmental Benefits:

Alternative technologies are reportedly able to reduce septic system effluent nitrogen concentrations by 50-70% depending on the nitrate loadings and the type of technology being used. The limits of conventional nitrogen removal technology are generally accepted as 3 mg/l of nitrogen. The NITREX™ filter is the only known treatment technology to provide virtually complete single-pass nitrate removal (97%+) to produce an effluent quality that meets the new stringent surface water discharge criteria for ammonium and nitrate.

Performance:

The NITREX™ filter easily meets the most stringent nitrate regulatory criteria. The NITREX™ filter is a low cost, easily installed solution that requires no pumping or chemical addition equipment and is maintenance free for many years after the installation. Over the past six years, numerous installations have been completed in various applications such as for single-family residential, commercial (e.g., hotel/truck-stop), campground, public school and large wastewater treatment systems. Overall average removal rates of 97%+ for nitrate (NO3-) have been attained, achieving nitrate NO3- - N effluent quality of 0.1 mg/l, when water temperatures are above 48o F.

Limitations:

For certain applications, the NITREX™ filter requires oxidative pre-treatment of the wastewater to convert ammonium (NH4+) to nitrate (NO3-). An oxidative pre-treatment step is usually not required for agricultural runoff NITREX™ filter applications. Only the NITREX™ reactive media, not the tankage, is eventually consumed and must be replenshed, estimated in 50 +/- years.

Cost:

For a typical residential septic system installation (3-4 bedroom home) the NITREX™ filter will cost approximately $4,200 - $5,000 (plus shipping and local installation costs). The pretreatment system materials costs are typically $8,000 - $12,000. With installation usually $4,000 - $6,000, a complete NITREX™ system cost would be $16,000 - $22,000. One would add the cost of a spectic tank-drainfield to obtain the total wastewater system cost for a property. Annual energy costs would be approximately $30, with electric rates of $0.125/kwhr.

For larger wastewater flows ( > 2,500 gal/day), a lined excavation NITREX™ filter application will cost approximately $5 – 12/gal/day. Sites requiring concrete tanks will cost approximately $18 - $22/gal/day of capacity. No additional ongoing operational or maintenance costs are necessary for the NITREX™ filter system. NITREX™ media replenishment is a fraction of the installation cost.

Installation of NITREX™ System at Wastewater Treatment Plant



The NITREX™ Filter has been evaluated in the following three (3) testing programs:

  1. LaPine Oregon National Decentralized Wastewater Treatment and Disposal Demonstration Project evaluating alternative innovative denitrification systems. The Project is being performed by the Oregon Department of Environmental Quality, U.S.G.S. and the Deschutes County Environmental Heath Division. Project is ongoing.
  2. Montana Department of Natural Resources evaluation of three on-site denitrification systems in Polson, MT. Project performed from Nov. 1999 to Aug. 2002.
  3. Massachusetts Septic System Test Center, Otis Air Force Base Cape Cod, MA and is ongoing. http://www.buzzardsbay.org/etimain.htm

In addition NITREX™ Filter systems have been operational at seven (7) installations in Canada since 1997 for individual and cluster wastewater systems, along with golf course and farmland runoff treatment systems. The NITREX™ Filter is under continual development at the University of Waterloo. Recent tests have confirmed that system start-up after a six month dormancy occurred without any nitrate laden wastewaters being discharged. The LaPine Oregon Project evaluated two NITREX™ Filters, along with 16 other technologies. A comparison of all the latest technologies is presented below for two (2) years of data.

Comparison of NITREX™ Nitrogen Removal System to 16 other Technologies

Otis Air Force Base,
Massachusetts Project

Project Description

The Nitrex™ system is one of a number of alternative septic systems technologies being assessed at the Massachusetts septic system test center.

Project Application Data

  • Location: Otis Air Force Base, Massachusetts
  • Site Application: Massachusetts Septic System Test Center
  • Installation Date: October 4, 2001

Design Profile

  • Design Wastewater Flow: 330 gpd
  • Wastewater Treatment Process: Septic Tank – ISF – Nitrex™

Nitrex™ Treatment Performance

The Nitrex™ filter installed at Otis Air Force base has reduced nitrogen in the effluent by an average of 74.1% over the two years that it has been in operation. The following figures illustrate the nitrate in the effluent and % of nitrate removed from the effluent due to the Nitrex™ filter. The Table provides the actual data measured by an independent laboratory. The lower winter 2003 wastewater temperature from the RSF reduced the performance of the Nitrex filter. The Nitrex filter can be easily modified to overcome the issue.


Contact:


Mr. George Heufelder
Barnstable County Department of Health
Post Office Box 427
Barnstable, MA 02630
(508) 375-6616

The Nitrex™ Filter technology is a patented technology with systems that have been tested in independent USEPA and state supported programs. Nitrex™ Filters have consistently produced wastewater effluent <3-4 ppm TN provided that wastewater temperature remains above 48° F. For colder wastewater applications special design considerations can be included to maintain desired effluent quality.

Lombardo Associates, Inc. is a full-service environmental engineering firm with wastewater and water projects in numerous states from New England to Florida. Lombardo Associates has been the Engineer of Record for over $200 million of wastewater and water projects and Chief Engineer for over $100 million of design, build and operate (DBO) projects. Lombardo Associates is a recipient of the prestigious American Consulting Engineer's Council Engineering Excellence Award for its innovative wastewater project. An Engineering News Record Construction Man of the Year candidate, Pio Lombardo was also designated an Entrepreneur of the Year finalist.

Contact:


Pio Lombardo, P.E.
Lombardo Associates, Inc.
Environmental Engineers/Consultants
188 Church Street
Newton, MA 02458
Tel: 617-964-2924
Fax: 617-332-5477
Email: Pio@LombardoAssociates.com

Burford, Ontario Project

Project Description


A 35 unit senior citizen’s complex located in Burford, Ontario has had a Nitrex™ Filter system installed since 1999 to produce wastewater effluent with a Total Nitrogen concentration less than 10 ppm that is discharged to a soil absorption system. For the design flow of 3,500 gallons per day (gpd), wastewater is treated by a septic tank, then an intermittent sand filter (ISF) is used for pre-treatment and the final disposal goes to a conventional tile bed. Groundwater monitoring wells are located 52 m downstream of the end of the tile beds.

Project Application Data

  • Location: Burford, Ontario
  • Site Application: 35 unit senior citizen complex, residential Wastewater
  • Installation Date: March 20, 1999

Design Profile

  • Design Wastewater Flow: 3,500 gpd
  • Wastewater Treatment Process: Septic Tank – ISF – Nitrex™


* indicates values that were interpolated based on the average of known data

Nitrex™ Treatment Performance

The Nitrex filter installed at Burford, Ontario has provided almost complete (average of 98.6%) removal of nitrate from the sand filter effluent over the four years that it has been in operation. The following figures illustrate the nitrate in the effluent and % of nitrate removed from the effluent due to the Nitrex™ filter. The Table provides the actual data measured by an independent laboratory.

Contact:


Willie Maertens
Burford Seniors Housing Corp.
RR#3
Harley, Ontario NOE 1E0
Tel: 519-449-2893
Fax: 519-449-1380

The Nitrex™ Filter technology is a patented technology with systems that have been tested in independent USEPA and state supported programs. Nitrex™ Filters have consistently produced wastewater effluent <3-4 ppm TN provided that wastewater temperature remains above 48° F. For colder wastewater applications special design considerations can be included to maintain desired effluent quality.

Lombardo Associates, Inc. is a full-service environmental engineering firm with wastewater and water projects in numerous states from New England to Florida. Lombardo Associates has been the Engineer of Record for over $200 million of wastewater and water projects and Chief Engineer for over $100 million of design, build and operate (DBO) projects. Lombardo Associates is a recipient of the prestigious American Consulting Engineer's Council Engineering Excellence Award for its innovative wastewater project. An Engineering News Record Construction Man of the Year candidate, Pio Lombardo was also designated an Entrepreneur of the Year finalist.

Contact:


Pio Lombardo, P.E.
Lombardo Associates, Inc.
Environmental Engineers/Consultants
188 Church Street
Newton, MA 02458
Tel: 617-964-2924
Fax: 617-332-5477
Email: Pio@LombardoAssociates.com