Slow Release Fertilizer Materials Based on Magnesium Ammonium Phosphate. Pilot-Plant Granulation Studies

1979 ◽  
Vol 18 (3) ◽  
pp. 453-458 ◽  
Author(s):  
Peter H. Peng ◽  
William R. Ernst ◽  
G. L. Bridger ◽  
Edwin M. Hartley
2012 ◽  
Vol 65 (11) ◽  
pp. 1954-1962 ◽  
Author(s):  
E. Desmidt ◽  
K. Ghyselbrecht ◽  
A. Monballiu ◽  
W. Verstraete ◽  
B. D. Meesschaert

The removal of phosphate as magnesium ammonium phosphate (MAP, struvite) has gained a lot of attention. A novel approach using ureolytic MAP crystallization (pH increase by means of bacterial ureases) has been tested on the anaerobic effluent of a potato processing company in a pilot plant and compared with NuReSys® technology (pH increase by means of NaOH). The pilot plant showed a high phosphate removal efficiency of 83 ± 7%, resulting in a final effluent concentration of 13 ± 7 mg · L−1 PO4-P. Calculating the evolution of the saturation index (SI) as a function of the remaining concentrations of Mg2+, PO4-P and NH4+ during precipitation in a batch reactor, resulted in a good estimation of the effluent PO4-P concentration of the pilot plant, operating under continuous mode. X-ray diffraction (XRD) analyses confirmed the presence of struvite in the small single crystals observed during experiments. The operational cost for the ureolytic MAP crystallization treating high phosphate concentrations (e.g. 100 mg · L−1 PO4-P) was calculated as 3.9 € kg−1 Premoved. This work shows that the ureolytic MAP crystallization, in combination with an autotrophic nitrogen removal process, is competitive with the NuReSys® technology in terms of operational cost and removal efficiency but further research is necessary to obtain larger crystals.


<em>Abstract.</em>—A solid briquette fertilizer for use in the Pacific Northwest streams and elsewhere was identified from a variety of slow-release formulations (26 were tested with varying N:P<sub>2</sub>O<sub>5</sub>:K<sub>2</sub>O ratios and binders) using indoor trough and controlled field experiments. The use of a slow-release fertilizer is an innovative method for adding inorganic nutrients to nutrientpoor (oligotrophic) streams to increase autotrophic production and aid in the restoration of salmonid populations. A series of indoor trough experiments demonstrated that the majority of samples containing binders of molasses, hydrated lime, vegetable oil, bentonite, starch, acrawax, candle wax, and Daratak® XB-3631 (unpolymerized Saran™) dissolved too slowly. The fastest dissolution rates occurred with fertilizer briquettes having no binder or vegetable oil. Further trough and field studies using fertilizer with no binder and vegetable oil as binder examined the effects of varying N:P<sub>2</sub>O<sub>5</sub>:K<sub>2</sub>O ratios. Dissolution rates were varied by using different percentages of magnesium ammonium phosphate (MagAmP; its formula 7:40:0 N:P<sub>2</sub>O<sub>5</sub>:K<sub>2</sub>O) and urea (46:0:0). Optimal continual nutrient release for a period of four months was achieved with a fertilizer formulation of 17:30:0 (percent by weight N:P<sub>2</sub>O<sub>5</sub>:K<sub>2</sub>O), with a ratio of 75% MagAmP to 25% urea, and containing no binder. The dissolution rate for this product ranged from 4.6% to 6.6% per week (for field and trough experiments, respectively) in water of 0.15 m/s average velocity. These studies indicate that a slow-release fertilizer product can be manufactured to last approximately four months when applied in the spring to stimulate autotrophic production in nutrient deficient streams, thereby increasing forage and salmonid production.


2013 ◽  
Vol 2013 ◽  
pp. 1-3 ◽  
Author(s):  
Selcuk Sarikaya ◽  
Berkan Resorlu ◽  
Ekrem Ozyuvali ◽  
Omer Faruk Bozkurt ◽  
Ural Oguz ◽  
...  

A 28-year old man presented with left flank pain and dysuria. Plain abdominal film and computed tomography showed a left giant ureteral stone measuring 11.5 cm causing ureteral obstruction and other stones 2.5 cm in size in the lower pole of ipsilateral kidney and 7 mm in size in distal part of right ureter. A left ureterolithotomy was performed and then a double J stent was inserted into the ureter. The patient was discharged from the hospital 4 days postoperatively with no complications. Stone analysis was consistent with magnesium ammonium phosphate and calcium oxalate. Underlying anatomic or metabolic abnormalities were not detected. One month after surgery, right ureteral stone passed spontaneously, left renal stone moved to distal ureter, and it was removed by ureterolithotomy. Control intravenous urography and cystography demonstrated unobstructed bilateral ureter and the absence of vesicoureteral reflux.


Author(s):  
R. Boistelle ◽  
F. Abbona ◽  
Y. Berland ◽  
M. Grandvuillemin ◽  
M. Olmer

1991 ◽  
Vol 37 (12) ◽  
pp. 978-983 ◽  
Author(s):  
Berlin Nelson ◽  
James Struble ◽  
Gregory McCarthy

A strain of Bacillus pumilus, isolated from the soilborne sclerotia of a fungus, produced crystals of the mineral struvite (magnesium ammonium phosphate hexahydrate) on Difco nutrient agar and a yeast extract agar containing magnesium sulphate and potassium phosphate. Crystals were macroscopically observed after 6–20 days of bacterial growth and reached a maximum size of 3 × 0.5 mm. Crystals were identified by X-ray powder diffractometry. These findings support the hypothesis that bacteria are involved in the biogenic formation of struvite in nature. Key words: struvite, magnesium ammonium phosphate hexahydrate, Bacillus pumilus, biomineral.


2003 ◽  
Vol 10 (1) ◽  
pp. 1-5 ◽  
Author(s):  
TAKAHIDE OGATA ◽  
KOICHIRO AKAKURA ◽  
KEN-ICHI MIZOGUCHI ◽  
KAZUO MIKAMI ◽  
KUNIYOSHI NOZUMI ◽  
...  

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