Nitrogen and Phosphorus Removal from Urine by Sequential Struvite Formation and Recycling Process

Abstract

Recovering nutrients from urine as solid minerals such as struvite can eliminate many hurdles related to the use of liquid urine as fertilizer in the current urine separation systems. The focus of this study has been to increase nitrogen and phosphorus removal efficiencies by developing a struvite formation and recycling process. Struvite crystallization was carried out in urine samples by addition of MgO where 92% of phosphorus as orthophosphate was recovered. In order to optimize the use of calcined struvite in the struvite recycling step, four calcination treatments were tested and calcination at 200°C for 3 h was chosen for further experiments. To remove the remaining ammonia present in urine a struvite recycling step was used subsequently. Through sequential struvite formation and struvite recycling process up to 90% of ammonium nitrogen was successfully removed.

[Mg-Al]-LDH and [Zn-Al]-LDH as Matrices for Removal of High Loadings of Phosphate

“…2 In a similar way, other activities generate wastewater products with high phosphate concentration, like agriculture, animal breeding and domestic activities. [3][4][5][6] In most of the cases, the effluents are not treated and are simply thrown into rivers where they contribute to eutrophication, which occurs when the concentrations of nutrients in water bodies increase, resulting in intense reproduction of autotrophic organisms, especially algae and cyanobacteria. The increased respiration of autotrophs then leads to environments that are hypoxic or anoxic, threatening the aerobic fauna and flora.…”

Novel Sustainable Route for Synthesis of Hydroxyapatite Biomaterial from Biowastes

“…In fact, in recent years there has been growing interest in recycling nutrients recovered from urine. A significant amount of work has been done on struvite (MgNH 4 PO 4 ·6H 2 O) synthesis from urine for fertilizer applications. − …”

UV/H2O2 and UV/PDS Treatment of Trimethoprim and Sulfamethoxazole in Synthetic Human Urine: Transformation Products and Toxicity

“…1−3 Among all the wastewater streams entering into wastewater treatment plants (WWTPs), the treatment of sourceseparated urine has been viewed as a promising approach to minimize the harm of the pharmaceuticals, because urine not only contributes a significant portion of the pharmaceuticals in municipal WWTPs, 4,5 it also carries high toxic potential to aquatic organisms. 6−8 Moreover, recovering nutrients from urine, as a new resource recovery strategy, 9 also requires elimination of pharmaceuticals from urine. To date, nanofiltration membranes, 10 strong-base anion exchange polymer resins, 11 electrodialysis, 12 and struvite precipitation 13 have been investigated for removing pharmaceuticals from urine, all of which involved only physical separation of the pharmaceuticals and further treatment is still needed.…”

“…Pharmaceutical micropollutants in the environment have been regarded as a major threat to the ecosystem due to their adverse biological effect and the potential of inducing drug-resistant bacteria. Because pharmaceuticals discharged in wastewater cannot be effectively removed by traditional wastewater treatment technologies, this has resulted in widespread occurrence of pharmaceuticals in the aquatic environment worldwide. − Among all the wastewater streams entering into wastewater treatment plants (WWTPs), the treatment of source-separated urine has been viewed as a promising approach to minimize the harm of the pharmaceuticals, because urine not only contributes a significant portion of the pharmaceuticals in municipal WWTPs, , it also carries high toxic potential to aquatic organisms. − Moreover, recovering nutrients from urine, as a new resource recovery strategy, also requires elimination of pharmaceuticals from urine. To date, nanofiltration membranes, strong-base anion exchange polymer resins, electrodialysis, and struvite precipitation have been investigated for removing pharmaceuticals from urine, all of which involved only physical separation of the pharmaceuticals and further treatment is still needed.…”