Nutrient Concentration & Water Reclamation™ System
Digested Organics has developed an exclusive ultrafiltration (UF) and reverse osmosis (RO) solution for manure nutrient concentration and water reclamation. The Nutrient Concentration & Water Reclamation (NCWR)™ System can process raw manure and digestate (from any digester, including our BioEliminator™) and separate the flow into clean, reusable water–ideal for barn use or discharge–and concentrated liquid fertilizer. With most materials, we can recover more than 60% of the total volume as clean water while concentrating the nutrients about 3x.
How it Works
Liquid manure or digestate is first concentrated using our proprietary ultrafiltration modules. Our unique module geometry and stainless steel construction ensures high filtration rates, easy cleaning, and long filter life (10+ years!). The UF modules contain porous metal tubes with holes smaller than 0.1 micron, allowing them to capture of all the suspended solids, bacteria, and even some larger dissolved compounds. This process results in a thick concentrate stream that contains >95% of the phosphorus and most of the organic nitrogen of the incoming material, as well as a stream that is free of any suspended solids and pathogens (called the UF permeate or “tea-water”).
The liquid “tea-water” or UF permeate that passes through the UF module is then pumped through RO membranes. These are industry-standard spiral membranes that look like 8” diameter pipes and have pores so small only water can pass through. This step recovers about 80% of the UF permeate as clean water and generates a concentrate stream that contains mostly ammonia nitrogen and potassium.
The clean water produced by the RO system still contains trace amounts of ammonia that must be removed prior to discharge or reuse as drinking water. The water is passed through ion exchange tanks that contain a special resin that can bind ammonia, resulting in a final water with less than 1 ppm ammonia. The resin is regenerated periodically with sulfuric acid to produce ammonium sulfate fertilizer.
The final step is to polish and disinfect the water. First, the water is aerated to add some dissolved oxygen and then depending on its use, some hardness is added (calcium and/or magnesium). As a final step, the water is passed through an in-line UV disinfection system to ensure complete pathogen removal and the utmost safety of the water for reuse as drinking water or for discharge. Since nearly all organisms are considered to be removed by the UF and RO—this UV disinfection step is simply an extra precaution.
Comprehensive Service Plan
We have created a Comprehensive Service Plan (CSP) to cover all the associated operating costs of the NCWR system with the exception of electricity. With the CSP, you know upfront what it will cost you to process your manure or digestate. In every case we’ve looked at to date, our system can substantially reduce a farm’s cost for manure management. We also remotely monitor the performance of your system and make adjustments as needed, as well as perform quarterly visits for inspection and tuning, provide all required consumables, and ensure your 100% satisfaction.