Nanochromatography Monitoring of Urine Fertilizers

EPA Grant Number: SU836767
Title: Nanochromatography Monitoring of Urine Fertilizers
Investigators: Lahr, Rebecca H
Institution: Michigan State University
EPA Project Officer: Sergeant, Anne
Phase: I
Project Period: September 1, 2016 through August 31, 2017
Project Amount: $15,000
RFA: P3 Awards: A National Student Design Competition for Sustainability Focusing on People, Prosperity and the Planet (2016) RFA Text |  Recipients Lists
Research Category: Sustainability , P3 Awards , P3 Challenge Area - Water

Description:

Compile a nanochromatography fingerprint library for nutrients and contaminants expected in urine and urine-derived products; implement a fertilizer production system at an existing urine diverting toilet; field testing.

Objective:

The average American flushes urine down the toilet four times per day, rinsing approximately 300 mL of waste with several gallons of water purified to drinking standards. Not only are significant resources (water, money, energy, time) invested in the potable water used to flush wastes, but the urine stream contains the majority of the valuable N and P we send to wastewater treatment plants in a concentrated volume. Several technologies are well documented for producing fertilizer from human urine both in resource rich and resource limited settings; however, the “yuck” factor hinders implementation. Thus, there is a need for user-friendly, reliable, fast, cost-effective detection tools that empower communities to monitor contaminants of public health concern and provide constant proof of fertilizer quality. The proposed work will develop a method employing nanochromatography for monitoring concentrations of nutrients and contaminants through the fertilizer production process.

Approach:

Detection method development will involve separation of analytes from wastewater solutions by the “coffee ring” effect, in which water droplets that are allowed to dry on aluminum foil leave distinct “fingerprints” within the residues that remain after evaporation. Wastewater constituents are spatially separated by size and solubility within the residues; thus, the technique provides nanochromatographic separation. This research will 1) compile a library of residue patterns for nutrients and contaminants expected in urine and urine derived products, 2) implement a fertilizer production system at an existing urine diverting toilet installed in Detroit by the Michigan Urban Farming Initiative and EcoWorks, and 3) field test the nanochromatography detection system to monitor fertilizer production.

Expected Results:

Nanochromatography with Raman spectroscopy for chemical detection has previously recorded unique residue patterns for various aqueous samples and identified cyanotoxin contamination in surface water, ocular damage signs in human tear fluid, and osteoarthritis remnants in knee fluid. Furthermore, we have recorded unique residue patterns for fresh urine, hydrolyzed urine, and effluent from a struvite reactor with a cell phone camera and $18 jeweler’s loupe, suggesting the method will be useful for monitoring fertilizer production even in resource limited settings. Outputs of this work will include a method for monitoring reactor function as well as evaluation of a urine diversion and fertilizer production system at an urban farm.

Supplemental Keywords:

Urine diversion, source separation, struvite production, nutrient recovery, drop coating deposition Raman spectroscopy (DCDRS);