The Knight Nutrient Removal Device
The KNuRD™ is a patented technology that is designed to follow any onsite residential wastewater treatment device that treats to advanced secondary effluent standards. It is a passive, flow-thru unit that will reduce Nitrate and Phosphorus concentrations in effluent to acceptable levels.
The Need
Nitrogen (N) and Phosphorus (P) are essential nutrients for plant growth, but when excessive levels of N and P enter bodies of water the increase in plant growth leads to lowered recreational uses of that water and eventual oxygen deprivation in our rivers, lakes, and ponds. This oxygen deprivation, in-turn impacts aquatic animal life. Water bodies hold obvious environmental value and need to be preserved. In addition, the economic impact of lakes due to their tourism/ recreational usage is tremendous. Nitrate and Nitrite in ground water is a serious health risk, especially for young children. Seasonal use properties on lakes across the country are being converted to year-round use at record rates. All of these factors lead to increased importance to keep N and P out of our water bodies. EPA acknowledges the importance of N&P removal to improve water quality in several current documents .
The System
The KNuRD™ is a gravity flow, media filter which utilizes specific medias to adsorb any Nitrogen left after nitrification and denitrification and adsorb all forms of Phosphorus that are not removed in settled solids in the secondary process. The footprint of the unit is very small (under 25 ft2) to enable it to be incorporated into systems where space is very limited. The system, as all advanced treatment systems, requires regular maintenance. When inspection (recommended every 6 months) and field-testing indicate the need, the media in the unit must be exchanged. The exchange interval will be dependant upon the nutrient loading applied to the device. It is intended that the discharge from the unit will be polished by a soil treatment system after leaving the unit.
The Results
The KNuRD™ is proven to reduce N&P levels in secondary effluent significantly. In laboratory and field trials, results (verified by certified laboratories) indicate continual reductions over 50% for both Nitrogen and Phosphorus, with typical bench top testing effluent levels of <5 mg/L of Nitrate and <2 mg/L of Total Phosphorus. 
Figure 1Typical Bench Top Laboratory results for the KNuRD™ used for Phosphorus removal. Sample testing performed by certified laboratory.
I. The 1997 Response to Congress on Use of Decentralized Wastewater Treatment Systems, Voluntary Guidelines for Management of Onsite/Decentralized Wastewater Systems, and Onsite Wastewater Treatment Systems Manual are all available at WWW.EPA.GOV.
II. Adsorption is the process of electro-chemically bonding to the outside of particles.
III. Results indicate less than 5 mg/L 75% of the time.
For More Information about the KNuRd™, Contact Mark Noga:
This e-mail address is being protected from spam bots, you need JavaScript enabled to view it