Ammonia removal by magnesium ammonium phosphate precipitation in industrial wastewaters

1997 ◽  
Vol 36 (2-3) ◽  
pp. 225-228 ◽  
Author(s):  
Olcay Tünay ◽  
Isik Kabdasli ◽  
Derin Orhon ◽  
Saadettin Kolçak

In this study, the theoretical basis and limitations of magnesium ammonium phosphate (MAP) precipitation are investigated and experimentally tested for leather tanning industry. The MAP precipitation is applied to leather tanning wastewaters for both segregated flows containing high ammonia concentrations and combined flows. Segregated flow treatment on smaller volumes of wastewater provided an ammonia concentration of down to 150 mg l−1 NH3-N. The resulting ammonia concentration of MAP precipitation on combined wastewater is at the level of domestic wastewater which eliminates the need of further nitrogen removal in the biological treatment and provides an effluent quality acceptable for the public sewer.

2002 ◽  
Vol 45 (12) ◽  
pp. 205-215 ◽  
Author(s):  
G. Zengin, ◽  
T. Ölmez ◽  
S. Doğruel ◽  
I. Kabdaşlı ◽  
O. Tünay

Nitrogen is an important parameter of leather tanning wastewaters. Magnesium ammonium phosphate (MAP) precipitation is a chemical treatment alternative for ammonia removal. In this study, a detailed source-based wastewater characterisation of a bovine leather tannery was made and nitrogen speciation as well as other basic pollutant parameter values was evaluated. This evaluation has led to definition of alternatives for source-based MAP treatment. MAP precipitation experiments conducted on these alternatives have yielded over 90% ammonia removal at pH 9.5 and using stoichiometric doses. Among the alternatives tested liming-deliming and bating-washing was found to be the most advantageous providing 71% ammonia removal.


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.


2002 ◽  
Vol 46 (4-5) ◽  
pp. 231-239 ◽  
Author(s):  
I. Kabdaşli ◽  
O. Tünay ◽  
M.Ş. Çetin ◽  
T. Ölmez

Magnesium ammonium phosphate (MAP) precipitation has a potential for ammonium removal from industrial wastewaters. Application basis of this recent method of treatment has not been fully determined. In this study application of MAP precipitation to leather tanning wastewaters has been experimentally evaluated. Five alternative places of MAP precipitation in leather tanning wastewater treatment scheme tested were; instead of plain settling, after plain settling, after polyelectrolyte added plain settling, within the chemical precipitation and after biological treatment. Among these alternatives MAP application instead of plain settling and within the chemical precipitation were found to be most favourable and efficient by reducing the nitrogen load to the level of nutrient requirement in the biological stage. pH 9.0-9.5 and stoichiometric magnesium and phosphate doses were determined to be optimum conditions for MAP precipitation.


2003 ◽  
Vol 48 (1) ◽  
pp. 215-223 ◽  
Author(s):  
I. Kabdaşli ◽  
T. Ölmez ◽  
O. Tünay

Nitrogen removal from wastewaters has gained importance in recent years. In this paper protein precipitation and recovery potential of leather tanning industry wastewaters were experimentally evaluated. A protein profile for all sources was prepared. Liming was determined to be the most important protein source. Composite samples were made up to assess the protein precipitation applications. Isoelectric pH precipitation yielded around 50% protein removal between the optimum pH interval of 2.1-3.8. FeCl3 proved to be a very effective means of protein removal providing over 60% efficiency. Polyelectrolyte precipitation did not yield satisfactory results. Magnesium ammonium phosphate precipitation followed by acid precipitation of protein provided 85% ammonia removal in addition to 50% protein removal.


2000 ◽  
Vol 41 (1) ◽  
pp. 237-240 ◽  
Author(s):  
I. Kabdaslı ◽  
O. Tünay ◽  
İ. Öztürk ◽  
S. Yılmaz ◽  
O. Arıkan

Leachate from sanitary landfills is a strong wastewater in terms of organic matter and ammonia. Organic matter can be reduced by anaerobic plus aerobic treatment; however, ammonia reduction by nitrification often poses problems due to inhibition. In this study, ammonia removal by physical chemical treatment from young leachate and anaerobically treated young landfill leachate was experimentally investigated. Magnesium ammonium phosphate precipitation (MAP) and ammonia stripping at pH 12 provided ammonia removals over 90 and 85% respectively. Up to 80% COD removal was obtained with MAP precipitation of raw leachate.


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.


2020 ◽  

<p>Most of the major cities in our country are opposed to the problem of water pollution due to the uncontrolled leachate resulting from the decomposition of solid wastes in irregular landfills. The waste waters that have high nitrogen content such as leachate cause various problems like eutrophication. In this study; the preliminary treatment of leachate which formed on the landfill site storing solid wastes of Samsun Metropolitan Municipality by MAP (Magnesium ammonium phosphate) precipitation was examined. For this purpose, optimization of the parameters that affecting the MAP precipitation was performed and the conditions for optimum removal efficiency were investigated. As a result of MAP precipitation, various mole ratios were tested with the aim of providing the best ammonia removal efficiency. The maximum ammonia removal was found to be 90.63% at pH 9.5 and at Mg:NH4:PO4 ratio of 4: 1: 2.2. At this conditions the ammonia concentration was decreased from 1792 mg/L to 168 mg/L. Experimental data were also evaluated and the regression equations of ammonia and COD removal were obtained using Minitab 16 statistical software.</p>


2016 ◽  
Vol 30 (3-4) ◽  
pp. 218-226 ◽  
Author(s):  
Sreenivasan Ramaswami ◽  
Joachim Behrendt ◽  
Ge Wang ◽  
Susanne Eggers ◽  
Ralf Otterpohl

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