scholarly journals Recycling of Phosphorus and Ammonia Nitrogen from Digestate

2018 ◽  
Vol 64 (4) ◽  
pp. 36-39
Author(s):  
Katrin Calábková ◽  
Petra Malíková ◽  
Silvie Heviánková ◽  
Michaela Červenková
Keyword(s):  
Sewage Treatment ◽  
Ammonium Phosphate ◽  
Ammonia Nitrogen ◽  
Stoichiometric Ratio ◽  
Nitrogen And Phosphorus ◽  
Magnesium Ammonium Phosphate ◽  
Quality Of Water ◽  
Magnesium Ammonium ◽  
Stirring Time ◽  
High Concentrations

Abstract Digestate from biogas plants, formed by dewatering anaerobically stabilized sludge, is characteristic of high concentrations of phosphates and ammonia nitrogen suitable for further use. Phosphorus is an element widely used to produce fertilizers, and because of its continually shortening natural supplies, recycling of phosphorus is gaining on significance. Both phosphorus and nitrogen are important elements and their presence affect the quality of water resources. Both elements can contribute to eutrophication. At the same time, both phosphorus and ammonia nitrogen, are important elements for agricultural production, and therefore greater demands are being made on the effort to connect sewage treatment processes and the process of recycling of these nutrients. A suitable product of phosphorus and ammonia nitrogen are phosphates in the form of a structurally-poorly soluble precipitate of magnesium ammonium phosphate (struvite). This form of slowly decomposing fertilizer is distinguished by its fertilizing abilities. Compared to direct use of digestate as a fertilizer, struvite is more stable and can gradually release ammonia nitrogen for a long time without unnecessary losses. In the reported experiments, the precipitation efficiency of the recycling of ammonia nitrogen and phosphorus from the digestate liqour (liquid discharge from digestate) was, at a stoichiometric ratio of Mg2+: NH4+: PO43− (3.2: 1: 0.8) and a stirring time of 15 minutes, 87 % for ammonia nitrogen ions.

Study on the Treatment of Ammona-Nitrogen Wastewater by Magnesium Ammonium Phosphate

2011 ◽  
Vol 233-235 ◽  
pp. 528-531
Author(s):  
Li Na He ◽  
Hua Ye ◽  
Can Cao ◽  
Ying Fen Li
Keyword(s):  
Removal Rate ◽  
Nitrogen Concentration ◽  
Ammonium Phosphate ◽  
Ammonia Nitrogen ◽  
Ammonium Nitrogen ◽  
Precipitation Method ◽  
Magnesium Ammonium Phosphate ◽  
Effective Technology ◽  
Magnesium Ammonium ◽  
Natural Water Bodies

Large quantities of ammonia-nitrogen (-N) in wastewater is one of the main causes of eutrophication that endanger both natural water bodies and fresh water seriously. Thus, it is necessary to find an economic and feasible method to remove the ammonium-nitrogen in wastewater before they are returned to the environment. Magnesium ammonium phosphate precipitation method is one of the effective technology of wastewater treatment. In this paper, the influence of initial ammonia-nitrogen concentration, pH, temperature and mole ratio of :NH+4 :Mg2+were studied, What is more, the optimum condition of this process was determined. The results indicated that ammonia-nitrogen concentration is decreased from 1434 mg/L to 95.65 mg/L, and the removal rate reached 93.33% at the optimum conditions, which laying a foundation for the following biochemical treatment.

Ammonia Nitrogen Removal from Chlor-Alkali Chemical Industry Wastewater by Magnesium Ammonium Phosphate Precipitation Method

2012 ◽  
Vol 573-574 ◽  
pp. 1096-1100 ◽  
Author(s):  
Lei Zhu ◽  
Zhi Yong Guo ◽  
Xiu Yi Hua ◽  
De Ming Dong ◽  
Da Peng Liang ◽  
...  
Keyword(s):  
Nitrogen Removal ◽  
Chemical Industry ◽  
Ammonium Phosphate ◽  
Ammonia Nitrogen ◽  
Precipitation Method ◽  
Reagent Ratio ◽  
Magnesium Ammonium Phosphate ◽  
Removal Ratio ◽  
Magnesium Ammonium ◽  
Industry Wastewater

This study introduces a method of ammonia nitrogen removal from chlor-alkali industry wastewater by magnesium ammonium phosphate (MAP) precipitation. The effect of pH, reagent ratio and temperature were investigated. The pH was found to be the most significant factor. The optimal ammonia nitrogen removal ratio is about 46% under the condition of pH=10, reagent ratio n(Mg) : n(N) : n(P)=1.2 : 1.0 : 1.0 and temperature=35°C. According to this study, MAP precipitation method has the potential ability to be applied to remove ammonia nitrogen from chlor-alkali chemical industry wastewater.

Pretreatment of High Strength Ammonia Removal from Rare-Earth Wastewater by Magnesium Ammonium Phosphate (MAP) Precipitation

2012 ◽  
Vol 496 ◽  
pp. 42-45 ◽  
Author(s):  
Hao Wang ◽  
Guan Wen Cheng ◽  
Xiao Wei Song ◽  
Zai Han Xu ◽  
Jin Jie Meng ◽  
...  
Keyword(s):  
Rare Earth ◽  
Reaction Time ◽  
Removal Rate ◽  
Ammonium Phosphate ◽  
High Strength ◽  
Ammonia Nitrogen ◽  
Ammonia Removal ◽  
Molar Ratio ◽  
Magnesium Ammonium Phosphate ◽  
Magnesium Ammonium

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.

Phosphorus recovery using a crystallization process for Sewage Treatment Plant

2011 ◽  
Vol 6 (4) ◽  
Author(s):  
Kazuaki Shimamura ◽  
Tateki Kurosawa
Keyword(s):  
Sewage Treatment ◽  
Sewage Treatment Plant ◽  
Treatment Plant ◽  
Ammonium Phosphate ◽  
Recovery Process ◽  
Phosphorus Recovery ◽  
Phosphorus Concentration ◽  
Magnesium Ammonium Phosphate ◽  
Magnesium Ammonium ◽  
Verification Test

A novel phosphorus recovery process enabling an effective reuse of recovered phosphorus as a resource has been developed. Three processes, which match the characteristics (sewage component, concentration and flow rate, etc.) of the waste water or the sludge generated form sewage treatment, are introduced here. Verification tests carried out using a crystallization of magnesium ammonium phosphate revealed a phosphorus crystallization exceeding 85%. Moreover, these tests show that the recovered phosphorus can be reused as a fertilizer. Another verification test carried out using a crystallization of hydroxylapatite revealed that the phosphorus concentration is reduced to a few milligrams per liter. In addition it is found that the recovered hydroxylapatite can be reused as a phosphorus ore. Each of the three processes is revealed to contribute to prevention of water contamination, as well as the recovery of phosphorus as a resource.

Pilot Study on Removal and Recovery of Nitrogen and Phosphorus in Human Urine by Crystallization of Magnesium Ammonium Phosphate

2010 ◽  
Vol 113-116 ◽  
pp. 2310-2313
Author(s):  
Qiang Liu ◽  
Yu Lan Tang ◽  
Jing Xiang Fu ◽  
Yu Hua Zhao ◽  
Zhi Wang
Keyword(s):  
Reaction Time ◽  
Human Urine ◽  
Ammonium Phosphate ◽  
Molar Ratio ◽  
Nitrogen And Phosphorus ◽  
Experimental Conditions ◽  
Magnesium Ammonium Phosphate ◽  
Magnesium Ammonium ◽  
Initial Ph ◽  
Removal And Recovery

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.

The Removal of High NH3-N Concentration in Wastewater by Chemical Precipitation

2011 ◽  
Vol 233-235 ◽  
pp. 733-736
Author(s):  
Wei Hua Song ◽  
Jun Yin ◽  
Jian Hui Wang
Keyword(s):  
Ph Value ◽  
Removal Rate ◽  
Ammonium Phosphate ◽  
Chemical Precipitation ◽  
Ammonia Nitrogen ◽  
Precipitation Method ◽  
Magnesium Ammonium Phosphate ◽  
Ph Values ◽  
N Concentration ◽  
Magnesium Ammonium

A lab-scale study was conducted to precipitate the ammonia from high NH3-N concentration wastewater in the form of magnesium ammonium phosphate(MAP) by applying such chemicals such as MgCl2·6H2O and KH2PO4.The influences of pH value, reactive time and removal rate of ammonia nitrogen were tested.The results shows that the feasible pH values of crystallization and precipitation were between 8 and 10. The structure of struvite crystallization was destroyed under high pH value condition that resulted in ammonia nitrogen dissociating from MAP, which reduced the removal rate of ammonia nitrogen. Results also demonstrated that ammonia nitrogen was effectively reduced from initia1981mg/L to final 5 mg/L, which removal efficiency reached 99% with crystallization and precipitation method when the optimal pH, precipitation time mole ratio of Mg2+, NH4+, PO43- were 8.0, 20 min and 1.4∶1∶1.4 respectively.

Concentration of nutrients from urine and reject water from anaerobically digested sludge

2006 ◽  
Vol 54 (11-12) ◽  
pp. 437-444 ◽  
Author(s):  
M. Ek ◽  
R. Bergström ◽  
J.-E. Bjurhem ◽  
B. Björlenius ◽  
D. Hellström
Keyword(s):  
Membrane Filtration ◽  
Sewage Treatment ◽  
Ammonium Phosphate ◽  
Pilot Scale ◽  
Significant Loss ◽  
Magnesium Ammonium Phosphate ◽  
Reject Water ◽  
Magnesium Ammonium ◽  
Water Ph ◽  
Anaerobically Digested Sludge

Experiments with concentration of nutrients from source separated urine and reject water from digestion of sludge in sewage treatment plants (STP) have been performed in laboratory and pilot scale. The methods tested were membrane filtration with reverse osmosis (RO), evaporation, and precipitation of phosphorus and distillation of ammonia. In membrane filtration, pre-filtration with particle separation at 5–10 μm was enough to avoid clogging of the membranes. Separation of phosphorus (P), potassium (K) and sulphur (S) was almost 100%, while separation of nitrogen (N) was dependent on pH. The capacity of flux increased with temperature and pressure. In evaporation, all P, K and S were still in the concentrate, while pH had to be decreased to 4.5 to avoid significant loss of N. In precipitation and distillation, about 90% of P could be recovered from urine as magnesium ammonium phosphate (MAP) just by adding MgO. For the reject water pH was first increased by aeration to remove CO2. Ammonium can be distilled from the water phase after precipitation of MAP, without further increase of pH. At least 80–90% of N can be distilled in 5–10% of the total volume. The article also discusses the quality of different products, cost of separation, and energy and chemical demand.

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