| Title |
Emerging investigator series: thermodynamic and energy analysis of nitrogen and phosphorous recovery from wastewaters |
| ID_Doc |
14448 |
| Authors |
McCartney, SN; Watanabe, NS; Yip, NY |
| Title |
Emerging investigator series: thermodynamic and energy analysis of nitrogen and phosphorous recovery from wastewaters |
| Year |
2021 |
| Published |
Environmental Science-Water Research & Technology, 7, 11 |
| DOI |
10.1039/d1ew00554e |
| Abstract |
In a circular nutrient economy, nitrogen and phosphorous are removed from waste streams and captured as valuable fertilizer products, to more sustainably reuse the resources in closed-loops and simultaneously protect receiving aquatic environments from harmful N and P emissions. For nutrient reclamation to be competitive with the existing practices of N fixation and P mining, the methods of recovery must achieve at least comparable energy consumption. This study employed the Gibbs free energy of separation to quantify the minimum energy required to recover various N and P fertilizer products from waste streams of fresh and hydrolyzed urine, greywater, domestic wastewater, and secondary treated wastewater effluent. The comparative advantages in theoretical energy intensities for N and P recovery from nutrient-dense waste streams, such as fresh and hydrolyzed urine, were assessed against the other more dilute sources. For example, compared to reclaiming the nutrients from treated wastewater effluent at centralized wastewater treatment plants, the minimum energy required to recover 1.0 M NH3(aq) from source-separated hydrolyzed urine can be approximate to 40-68% lower, whereas recovering KH2PO4(s) from diverted fresh urine can, in principle, be approximate to 13-34% less energy intensive. The study also evaluated the efficiencies required by separation techniques for the energy demand of N and P recovery to be lower than the current production approaches of the Haber-Bosch process and phosphate rock mining. For instance, the most energetically favorable ammoniacal nitrogen and orthophosphate reclamation schemes, which target hydrolyzed and fresh urine, respectively, require energy efficiencies >7% and >39%. This study highlights that strategic selection of waste stream and fertilizer product can enable the most expedient recovery of nutrients and realize a circular economy model for N and P management. |
| Author Keywords |
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| Index Keywords |
Index Keywords |
| Document Type |
Other |
| Open Access |
Open Access |
| Source |
Science Citation Index Expanded (SCI-EXPANDED) |
| EID |
WOS:000702433200001 |
| WoS Category |
Engineering, Environmental; Environmental Sciences; Water Resources |
| Research Area |
Engineering; Environmental Sciences & Ecology; Water Resources |
| PDF |
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