Nitrogen removal and recovery from human urine by struvite precipitation

Human urine is a source of nutrients and has a significant potential for recycle of nitrogen. Recently, much research focused on separate collection and treatment of human urine. Recovery of nutrients from human urine requires hydrolysis of urea into ammonia and subsequent removal of ammonia and sometimes phosphorus. This study attempted to evaluate urea hydrolysis of human urine in both untreated fresh samples and urease added urine samples. Recovery of nutrients by struvite precipitation on pre-hydrolysed samples was also assessed on undiluted and 1:1 diluted samples. Results of urea hydrolysis on untreated urine samples indicated that the process was slow and pH exerted a significant effect on the process. No hydrolysis occurred above pH 10. From pH 2 to 7.5, 25% of urea could be hydrolysed in 30 d. Urease added hydrolysis with the enzyme doses 25–49 mg L−1 was a rapid process providing complete conversion into ammonia in 1.5 h. Struvite precipitation conducted on enzyme hydrolysed urine sample proved to be an efficient process and ammonia removals up to 95% were obtained. Struvite precipitation also provided 50% organic nitrogen removal.

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Bioelectrochemical Ammonium Production – Nitrogen Removal and Recovery in BES

Bioelectrosynthesis ◽

10.1002/9783527343829.ch8 ◽

2020 ◽

pp. 217-231

Author(s):

Guoqiang Zhan

Keyword(s):

Nitrogen Removal ◽

Ammonium Production ◽

Removal And Recovery

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Nitrogen and Phosphorus Recovery from Human Urine by Struvite Precipitation and Air Stripping in Vietnam

CLEAN - Soil Air Water ◽

10.1002/clen.201100036 ◽

2011 ◽

Vol 39 (12) ◽

pp. 1099-1104 ◽

Cited By ~ 55

Author(s):

Samantha Antonini ◽

Stefania Paris ◽

Thomas Eichert ◽

Joachim Clemens

Keyword(s):

Human Urine ◽

Phosphorus Recovery ◽

Nitrogen And Phosphorus ◽

Air Stripping ◽

Struvite Precipitation

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Model-based evaluation of struvite recovery from an in-line stripper in a BNR process (BCFS)

Water Science & Technology ◽

10.2166/wst.2006.092 ◽

2006 ◽

Vol 53 (3) ◽

pp. 191-198 ◽

Cited By ~ 13

Author(s):

X.-D. Hao ◽

M.C.M. van Loosdrecht

Keyword(s):

Nutrient Removal ◽

Phosphate Concentration ◽

Phosphate Removal ◽

Carbon Oxidation ◽

P Efficiency ◽

Effluent Quality ◽

P Recovery ◽

Struvite Precipitation ◽

Removal And Recovery ◽

P Removal

Phosphate removal and recovery can be combined in BNR processes. This may be realised by struvite precipitation from the supernatant of the sludge in anaerobic compartments. This can be beneficial for either improving bio-P removal effluent quality or lowering the influent COD/P ratio required for bio-P removal. For this reason, a patented BNR process, BCFS®, was developed and applied in The Netherlands. Several questions relating to P-recovery and behaviour of the system remain unclear and need to be ascertained. For this purpose, a modelling technique was employed in this study. With the help of a previous developed model describing carbon oxidation and nutrient removal, three cases were fully simulated. The simulations demonstrated that there was an optimal stripping flow rate and P-recovery would increase in costs and bio-P activity might be negatively affected due to decreased bio-P efficiency if this value was exceeded. The simulations indicated that the minimal CODbiod/P ratio required for the effluent standard (1 g P/m3) could be lowered from 20 to 10 with 36% of P-recovery. A simulation with dynamic inflow revealed that the dynamic influent loads affected slightly the anaerobic supernatant phosphate concentration but the effluent phosphate concentration would not be affected with regular P-recovery.

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Scaling-up Bioelectrochemical Systems for nitrogen removal and recovery from waste streams = Escalado de sistemas bioelectroquímicos para eliminación y recuperación de nitrógeno en aguas residuales

10.18002/10612/11085 ◽

2019 ◽

Author(s):

Isabel San Martín Bécares

Keyword(s):

Nitrogen Removal ◽

Scaling Up ◽

Bioelectrochemical Systems ◽

Waste Streams ◽

Removal And Recovery

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Phosphorus recovery as struvite from eutropic waters by XDA-7 resin

Water Science & Technology ◽

10.2166/wst.2012.121 ◽

2012 ◽

Vol 65 (12) ◽

pp. 2091-2097 ◽

Cited By ~ 11

Author(s):

Huanwen Li ◽

Zhiping Ye ◽

Ying Lin ◽

Fengying Wang

Keyword(s):

Ammonium Phosphate ◽

Phosphorus Recovery ◽

Phosphate Adsorption ◽

Nacl Solution ◽

Acid Dissolution ◽

Magnesium Ammonium Phosphate ◽

Magnesium Ammonium ◽

Struvite Precipitation ◽

Ph Range ◽

Removal And Recovery

Phosphorus releases into aquatic environment and its subsequent contribution to eutrophication have resulted in a widespread global pollution issue. However, phosphorus is a non-renewable source. The potential supplies of phosphorus are decreasing worldwide. Therefore, removal and recovery of phosphorus from the eutropic waters is important, emergent and necessary. In this research, experiments for recovering phosphate from eutropic waters by anion exchange combined with struvite precipitation were conducted. The results indicated that the prepared XDA-7 resin was an effective adsorbent for phosphate. The adsorption isotherm of XDA-7 resin was found to be a modified Freundlich type. The maximum phosphate adsorption (20.9 mg/g) occurred in the pH range of 6.0–8.0. Phosphate adsorbed on the XDA-7 resin was effectively desorbed with 8% NaCl solution, and the resin was able to be regenerated with 3% NaClO and 4% NaOH solutions. Phosphate desorbed from the resin was recovered as magnesium ammonium phosphate (struvite). The obtained struvite was analyzed by acid dissolution method, scanning electron microscope (SEM) and Fourier transform infrared spectroscopy (FTIR). The struvite precipitate was found to be 75.8% in purity, a high-value fertilizer.

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The Mechanism and Influence Factors of Struvite Precipitation for the Removal of Ammonium Nitrogen

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.189-193.2613 ◽

2011 ◽

Vol 189-193 ◽

pp. 2613-2620 ◽

Cited By ~ 1

Author(s):

Hai Ming Huang ◽

Qian Wu Song ◽

Chun Lian Xu

Keyword(s):

Wastewater Treatment ◽

Nitrogen Removal ◽

Influence Factors ◽

Ammonium Nitrogen ◽

Double Salt ◽

Normal Operation ◽

Research Directions ◽

Struvite Precipitation ◽

At Home

Struvite (MgNH4PO4∙6H2O) is an insoluble double salt. It can precipitate in places such as pipes, aerators and pumps, which could lead to substantial problems influencing the normal operation of wastewater treatment equipments. At present, removal of ammonium nitrogen from various wastewaters by the formation of struvite has been widely investigated. This paper reviewed the research and application efforts concerning the treatment of ammonium nitrogen by struvite precipitation, which were obtained at home and abroad in recent years. The mechanism and influence factors of struvite precipitation for ammonium nitrogen removal were discussed. Additionally, the problems that still should be resolved and the research directions in future were pointed out.

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