scholarly journals Recovery of Phosphate and Ammonium from Dairy Cow Urine by Struvite Crystallization with Vertical Reactor

Author(s):  
Luluk Edahwati ◽  
Sutiyono ◽  
Rizqi Rendri Anggriawan

Excess phosphate (PO43-) and ammonium (NH4+) in wastewater can cause environmental damages, such as pollutants and eutrophication in water. Dairy cow urine is a dangerous liquid waste that contains high amounts of phosphate and ammonium. The removal of PO4 and NH4 components can be done by crystallizing them into struvite fertilizers. Struvite (MgNH4PO4.6H2O) is a mineral formed from magnesium, ammonium, and phosphate with the equimolar ratio. The crystallization process of struvite is carried out using a vertical reactor. MAP solution (magnesium ammonium phosphate) is prepared by reacting MgCl2, H3PO4, and dairy cow urine with MAP molar ratio of 1 : 1 : 1 and KOH 1N. The study run in pH 8; 8.5; 9; 9.5; 10 and temperature variations of 25, 30, 35, 40, 45˚C  in vertical reactor continuously. The struvite precipitate was filtered and dried, it is analyzed by XRF to determine the struvite composition and SEM to determine the morphology of the struvite. The results showed that the best percentage of phosphate and ammonium was at 45˚C and pH 9.5, it was 33.2% and 27.9%.

Author(s):  
Sutiyono ◽  
Luluk edahwati ◽  
Kartika Pratiwi ◽  
Achmad Fanani

Struvite is a white crystal, chemically known as magnesium ammonium phosphate hexahydrate (MgNH4PO4.6H2O). Tofu factory liquid waste is waste that can be reused because of its content. Tofu factory liquid waste can potentially pollute the environment. This research aimsto analyze the manufacture of struvite by utilizing the phosphate content contained in the liquid waste of tofu factories using vertical canted column reactors which can reduce environmental pollution due to liquid waste of tofu factories. This study uses a vertical canted column reactors by mixing anequimolar 1: 1: 1 MgCl2: NH4OH: H3PO4 solution. Struvite crystallization process operates at a temperature variation of 30°C,35°C,40°C,45.50°Cand a pH of 8, 9,10,11,12 by maintaining the air rate of 0.5 liters minute-1 and a MAP (Magnesium Ammonium Phosphate)flow of 56 ml minutes-1 as a whole. The crystallization process runs until a steady state conditionis reached. Then, the struvite crystals obtained were filtered and dried at room temperature for 24 hours. After that struvite crystals were analyzed using XRF, XRD, and SEM. The results of the study obtained the best phosphate conversion of 24.935% at 30°C  and pH 8.


2013 ◽  
Vol 68 (12) ◽  
pp. 2661-2667 ◽  
Author(s):  
Rongtai Yu ◽  
Subin Cheng ◽  
Hongqiang Ren ◽  
Yanru Wang ◽  
Lili Ding ◽  
...  

Magnesium ammonium phosphate (MAP) pyrolysate recycling technology was investigated with Mg(OH)2-mediated pyrolysis. The results revealed that the removal ratio of ammonium was stable at about 75%, and could be increased to 79% after additional acidolysis. The phosphate concentration in the supernate was low at 2 mg/L. The optimum conditions for ammonia release were a 1:1 molar ratio of Mg(OH)2:NH4+, a heating temperature of 110 °C and a heating time of 3 h. With continual additions of Mg(OH)2 to release ammonia, magnesium phosphate (Mg3(PO4)2) was suggested as a possible derivative. However, with Mg(OH)2-mediated pyrolysis, the growth and nucleation of MAP was inhibited during MAP pyrolysate recycling.


2013 ◽  
Vol 295-298 ◽  
pp. 1289-1292 ◽  
Author(s):  
Kai Huang ◽  
Li Ping Qiu ◽  
Jin Feng Meng ◽  
Dong Wang

By- products are widespread in the crystallization of magnesium ammonia phosphate (MAP) as the differences in reactive conditions which effects the forms and habits of crystals. The study focused on the supernatant from septic tank in order to achieve in-situ treatment. Based on the effluent, the optimization research of initial phosphate concentration and pH was investigated by using single factor analysis. The crystal products with different reaction condition were also characteristiced through the XRD analysis. The experimental results showed that the optimum reactants molar ratio of n(NH4+):n(Mg2+):n(PO43-) were 90:25:1, 4:1.6:1 and 3:1.4:1 when pH value was 9.5 with initial phosphate concentration 8mg/L, 50mg/L and 100mg/L, respectively. It was also observed that the phosphate removal rate increased with increasing the initial phosphate concentration or pH value. As the aging time increased, the removal rate was in parabolic curve with 30 minute at the highest point. The XRD analysis revealed that the best MAP crystal could be produced with initial phosphate concentration 50mg/L and pH 9.0.


2021 ◽  
Vol 328 ◽  
pp. 01016
Author(s):  
Sutiyono Sutiyono ◽  
Luluk Edahwati ◽  
Atika Nandini ◽  
W D Lestari ◽  
Wiliandi Saputro ◽  
...  

Scale is forming and controlling in industrial applications causes the clogs or decreasing in volume flows in the pipes, so increasing maintenance cost can occur as a consequence. Struvite discovered as Magnesium Ammonium Phosphate Hexahydrate (MgNH4PO4.6H2O) and referred as a scale due to the heating process of fluid through pipes. The aim of this research was investigated the temperature effect on process of scales forming and controlling. The process was used a vertical bulkhead reactor. The process starts from mixing the equimolar solutions of MgCl2, NH4OH, H3PO4 with 1: 1: 1 of ratio concentration. Then, crystallization process was carried out with the condition at the variation of temperature (20-40°C), variation of pH value (pH 8-10) and variation of air inlet rate (0.25; 0.50; 0.75; 1.0; 1.25 L/min) while the feed rate was 25 ml/min. The process continues until the condition becomes steady state. The scale controlling process was determined by the presence of struvite deposits. The deposits were analyzed by using the XRF method to determine composition content. The optimal conditions were obtained at a temperature of 30°C, pH 9, and air rate of 1.25L/min.


2012 ◽  
Vol 496 ◽  
pp. 42-45 ◽  
Author(s):  
Hao Wang ◽  
Guan Wen Cheng ◽  
Xiao Wei Song ◽  
Zai Han Xu ◽  
Jin Jie Meng ◽  
...  

Ammonia is one of the most important contaminants affecting the quality of water environment. Magnesium ammonium phosphate (MgNH4PO4·6H2O), which is a slow releasing fertilizer, is one possible way to remove high strength ammonia from the wastewater. The wastewater is collected from the effluent of extraction of rare earth elements factory, the study investigate the influence of pH, magnesium and phosphate dosing molar ratio and reaction time for ammonia removal rate. The results show that: when the pH = 9.2, n (Mg): n (N): n (P) = 2.2:1:2, reaction time t = 20min, ammonia concentration of the wastewater from 4420mg / L down to 1440mg / L , ammonia nitrogen removal rate can reach 67%, the remaining TP = 0.9mg / L; higher Ca2 + concentration will affect the MAP precipitation for removing ammonia, but it help to reduce total phosphorus concentrations of effluent; it is not the longer reaction time the better removal rate, because the MAP-formation will destroy with longer reaction time.


2001 ◽  
Vol 43 (11) ◽  
pp. 259-266 ◽  
Author(s):  
A. Miles ◽  
T. G. Ellis

Geochemical equilibrium speciation modeling was used to determine optimum conditions for precipitation of magnesium ammonium phosphate, or struvite, for the recovery of nutrients from anaerobically digested wastes. Despite a wide range of pH values with the potential to precipitate struvite, the optimum pH was determined to be 9.0. Bench experiments conducted on effluent from an anaerobic sequencing batch reactor (ASBR) treating swine wastes achieved a maximum of 88% ammonia removal at a pH of 9.5 with added magnesium and phosphate to achieve an ammonium: magnesium: phosphate molar ratio of 1:1.25:1. Struvite precipitation was performed on a continuous basis in a pilot-scale ASBR treating swine wastes. Through the addition of supplemental magnesium and phosphate, the ammonia concentration was reduced from 1500 mg/L as nitrogen to less than 10 mg/L. The supematant from the struvite precipitation clarifier was recycled to the feed of the ASBR without adverse impact, simulating on-farm effluent reuse as flush water.


2017 ◽  
Vol 19 (2) ◽  
pp. 251-256 ◽  

Chemical precipitation is a suitable method for the recovery and removal of ammonium in water and a fertilizer known as MAP (magnesium ammonium phosphate; MgNH4PO4.6H2O; struvite) is obtained. Additionally, the advantage of this method is that environmental conditions do not have any effect compared to biological methods. In this study, the recovery of ammonium (Cmean=348 mg NH4 +/L ± 38.1; n=25) occurred after the hydrolysis of urea in the biocatalytic calcification reactor (BCR) effluent and it precipitated as struvite. The effects of operating parameters, such as different phosphate and magnesium sources, Mg2+:NH4+:PO43- molar ratio, pH value, mixing speed-time, and fertilizer effect, were examined. The precipitates were characterized by X-ray diffraction and scanning electron micrograph. The optimum molar ratio of Mg2+:NH4+:PO43− was determined as 1.25:1:1. Studies using different pH ranges (7–10) and this molar ratio showed that the ammonium recovery of approximately 96% was reached at a pH value of 9.36. It was seen that the rapid mixing (200 rpm) of 30-s period and the slow mixing (30 rpm) of 2-min period were sufficient for MAP precipitation. Struvite that was obtained after precipitation was used as a fertilizer and it was observed to have a positive effect on plant growth.


2010 ◽  
Vol 113-116 ◽  
pp. 2310-2313
Author(s):  
Qiang Liu ◽  
Yu Lan Tang ◽  
Jing Xiang Fu ◽  
Yu Hua Zhao ◽  
Zhi Wang

Laboratory-scale tests for removal and recovery of nitrogen and phosphorus in human urine were conducted by magnesium ammonium phosphate precipitation (MAP) method. Proper Na2HPO4•12H2O as a phosphorus source and MgCl2•6H2O as a magnesium source were added to adjust the ratio of Mg2+, NH4+and PO43-. The effects of initial pH, (Mg2+): n (NH4+), n (PO43-) : n (NH4+), temperature, reaction time and stirring speed on removal and recovery of nitrogen and phosphorus in urine were studied by MAP method. Results showed that the optimum experimental conditions were at room temperature, pH, the molar ratio of Mg2+:PO43-:NH4+, reaction time and stirring speed were set 10, 1.2:1:0.9, 30min and 100r/min.


2009 ◽  
Vol 59 (6) ◽  
pp. 1093-1099 ◽  
Author(s):  
H. M. Huang ◽  
X. M. Xiao ◽  
B. Yan

This paper presents a recycle MAP process (magnesium ammonium phosphate) to remove NH4-N from a typical rare-earth wastewater. The optimum conditions for the MAP precipitation and recycle use of the MAP with a newly-designed process were investigated in laboratory. The results showed that the pH value and dosages of P (phosphate) and Mg reagents have a significant influence on NH4-N removal, with a maximum removal efficiency of 99.4% at the conditions of pH = 9 and Mg:N:P molar ratio =1.2:1:1.2. In the process of recycle use of the MAP, adding some HCl to dissolve MAP decomposition residues could effectively enhance NH4-N removal. The NH4-N removal efficiency reached 99.6% by adding an HCl amount of H+:OH− molar ratio = 0.8 into the reused MAP decomposition residues, whereas the NH4-N removal efficiency without addition of HCl was only 96.4%. Moreover, the residual PO4-P from the end of reaction was recovered and the optimum recovery efficiency was achieved at a Mg:P molar ratio = 6 and pH = 10. Under these optimum conditions, the residual NH4-N and PO4-P concentrations in the treated wastewater, through 6 times of the recycling, were less than 15 mg/L and 1 mg/L, respectively. On the basis of this, an economic evaluation of the recycling MAP was made, and this recycle process could save 48.6% cost used in the chemicals for treating per cubic meter of the rare-earth wastewater, compared to the conventional MAP process.


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