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Sustainable Wastewater Treatment: Nutrient Upcycling of Ammonia into FertilizerEPA Grant Number: SU835513
Title: Sustainable Wastewater Treatment: Nutrient Upcycling of Ammonia into Fertilizer
Investigators: Barak, Phillip
Institution: University of Wisconsin - Madison
EPA Project Officer: Levinson, Barbara
Project Period: August 15, 2013 through August 14, 2014
Project Amount: $14,996
RFA: P3 Awards: A National Student Design Competition for Sustainability Focusing on People, Prosperity and the Planet (2013) Recipients Lists
Research Category: Pollution Prevention/Sustainable Development , P3 Challenge Area - Water , P3 Awards , Sustainability
We propose to build an electrodialysis cell to be incorporated into existing wastewater treatment facilities to remove and concentrate the ammonium cation (NH4+) from the wastewater stream and generate a high value commercial fertilizer, ammonia (NH3), from the recovered ammonium, by adding a chemical base. Our objective is to design this electrodialysis technology to be adaptable to different wastewater streams, encompassing large advanced treatment wastewater treatment plants down to on-farm manure digesters. Our overarching goal is to upcycle low grade wastewater by-products into high value fertilizer products, concentrating nutrients to be distributed and applied as needed for plant growth and keeping excess nitrogen out of surface waters and groundwater.Approach:
Electrodialysis is an electrically driven membrane process used to remove ionic species from brackish or waste water or, in the present case, to concentrate the salts in a process stream. An electric potential is applied with a DC power supply through two electrodes immersed in an ionic solution, causing the ions to move towards the oppositely charged electrodes. The movement of these ions is further controlled by compartmentalizing the solution tank with cation and anion exchange membranes, each only allowing respectively either a cation or anion to pass through. High efficiencies, 50-84%, have been achieved in converting electrical power into ion separations and seven-fold concentrations of salts have been previously reported.
The people impacted will range from engineers and plant operators to dairy and grain farmers. Recovery of ammonium as ammonia could potentially create over $1 billion in savings. The sustainability of the planet would be benefited by: reduction of nitrous oxide emissions from wastewater treatment plants, reduction in nitrate release into surface water and subsequent eutrophication, reduction of natural gas consumption required during synthesis to replace the ammonia recovered, reduction of CO2 emissions produced during synthesis to replace the ammonia, and reduction of ammonia emissions from manure storage and subsequent ammonium deposition across the landscape.
Our P3 project will create a Soils 375 “Ammonia Recovery from Wastewater” capstone course for our team of undergraduates. We propose that the P3-funded students will, in Fall 2013, tour and collect samples from three diverse wastewater streams--the Madison Metropolitan Sewerage District Nine Springs Facility, the Dane County Manure Digester operated by Clear Horizons, and the Montchevré Cheese Plant Digester operated by Procorp, LLC--to understand the nutrient removal processes currently in place and the factors that influenced their design. They will have an opportunity to design experiments, with faculty direction, to concentrate ammonium and reduce fouling, calculate efficiency from analytical results, and determine the feasibility of electrodialysis for ammonium recovery and ammonia production from wastewater streams. The course will challenge them to identify ways to transform the current designs into resource recovery, comparing the nutrient values and potential for ammonia recovery for each facility to the cost of recovery.Expected Results:
We intend to identify appropriate locations for treatment and feasibility of recovery for each of three types of wastewater treatment plants: municipal sewage treatment, manure digester, and cheese processing waste digester. We anticipate that a modular design for the electrodialysis unit would be able to be incorporated into wastewater treatment facilities of many varieties.
Although the plants we are investigating have methane-generated electrical power, the electrodialysis technology is inherently agnostic with regard to the source of the power and photovoltaic solar power could drive this technology where appropriate, as could wind turbines. Further, although we have considered here considered production of ammonia, which can be trapped by condensation and stored by refrigeration, alternatively ammonia can be trapped in a number of readily available acids to produce ammonium sulfate (sulfuric acid), ammonium nitrate (nitric acid), and mono- and di-ammonium phosphate (phosphoric acid), all well-known fertilizer materials.
UW-Madison capstones require a public presentation of findings in one format or another, and we anticipate that in addition to the P3 Expo in Washington, D.C., the entire team will make both a PowerPoint presentation at the UW-Madison campus and either an animated PowerPoint presentation or a YouTube-type video for general distribution as part of their course summary requirements.
Water treatment. Treatment technologies;