Method for recycling ammonia and nitrogen in waste watery by aid of chemicrystallization

A technology for chemical crystallization and waste water, which is applied in chemical instruments and methods, water/sewage treatment, water/sludge/sewage treatment, etc. It can solve the problems of high chemical cost and decreased removal rate of ammonia nitrogen, etc., so as to reduce chemical cost and improve Release rate, the effect of solving the high cost of medicine

Active Publication Date: 2012-09-19
NANJING UNIV
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  • Claims
  • Application Information

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Problems solved by technology

[0006] Aiming at the problems of high cost and low removal rate of ammonia nitrogen in waste water by ammonium magnesium phosphate crystallization method in the prior art, the present invention provides a method for recovering ammonia nitrogen in waste water by chemical crystallization, which can effectively solve the problem of ammonium magnesium phosphate crystallization method The problem of high cost, and at the same time solve the problem that the removal rate of ammonia nitrogen decreases with the increase of the number of ammonium ammonium phosphate cycle precipitation

Method used

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  • Method for recycling ammonia and nitrogen in waste watery by aid of chemicrystallization
  • Method for recycling ammonia and nitrogen in waste watery by aid of chemicrystallization
  • Method for recycling ammonia and nitrogen in waste watery by aid of chemicrystallization

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Embodiment 1

[0033] The coking wastewater was taken, and the quality of the wastewater is shown in Table 1.

[0034] Table 1 Water quality of coking wastewater

[0035] parameter unit concentration COD mg / L 220±10 pH - 7.2±0.1 NH 4 -N mg / L 650±20 BOD mg / L 50±1 Ca 2+ mg / L 21±0.5

[0036] A kind of chemical crystallization method of the present embodiment reclaims the method for ammonia nitrogen in waste water, and its steps are:

[0037] (1) Prefabrication of magnesium ammonium phosphate crystals, adding sodium hydroxide powder to the solid ammonium magnesium phosphate for pyrolysis, the mass ratio of sodium hydroxide: magnesium ammonium phosphate is 40:245, the pyrolysis temperature is 110 ℃, and the pyrolysis time is 3 h, the ammonia produced by pyrolysis is recovered by a sulfuric acid solution with a mass fraction of 2%;

[0038] (2) Put the pyrolysis product prepared in step (1) into the waste water in Table 1, wherein, the m...

Embodiment 2

[0044] Breeding wastewater was taken, and the quality of the wastewater is shown in Table 2.

[0045] Table 2 Water quality of aquaculture wastewater

[0046] parameter unit concentration COD mg / L 550±10 pH - 7.4±0.1 NH 4 -N mg / L 860±20 BOD mg / L 90±10 TOC mg / L 120±10

[0047] A kind of chemical crystallization method of the present embodiment reclaims the method for ammonia nitrogen in waste water, and its steps are:

[0048] (1) Prefabrication of magnesium ammonium phosphate crystals, adding sodium hydroxide powder to the solid ammonium magnesium phosphate, the mass ratio of sodium hydroxide: magnesium ammonium phosphate is 80:245, the pyrolysis temperature is 100 °C, and the pyrolysis time is 2 h. Ammonia produced by pyrolysis is recovered with a sulfuric acid solution with a mass fraction of 2%;

[0049] (2) Add the pyrolysis product obtained in step (1) to the breeding wastewater in Table 2. The mass ratio of pyro...

Embodiment 3

[0055] The waste water from the fertilizer industry was taken, and the quality of the waste water is shown in Table 1.

[0056] Table 3 Wastewater quality of chemical fertilizer industry

[0057] parameter unit concentration COD mg / L 560±10 pH - 7.86±0.1 NH 4 -N mg / L 1197±20 SS mg / L 10±1 Mg 2+ mg / L 0.516±0.1

[0058] A kind of chemical crystallization method of the present embodiment reclaims the method for ammonia nitrogen in waste water, and its steps are:

[0059] (1) Prefabrication of magnesium ammonium phosphate crystals, adding sodium hydroxide powder to the solid ammonium magnesium phosphate, the mass ratio of sodium hydroxide: magnesium ammonium phosphate is 60:245, the pyrolysis temperature is 105 °C, and the pyrolysis time is 2.5 h. Ammonia produced by pyrolysis is recovered with a sulfuric acid solution with a mass fraction of 2%;

[0060] (2) Put the pyrolysis product obtained in step (1) into the waste w...

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Abstract

The invention discloses a method for recycling ammonia and nitrogen in waste water by the aid of chemicrystallization, and belongs to the field of waste water treatment. The method includes (1) adding sodium hydroxide powder into magnesium ammonium phosphate solid, performing pyrolysis to obtain a pyrolysis product; (2) feeding the pyrolysis product obtained in the step (1) into the waste water to obtain magnesium ammonium phosphate crystal sediment; (3) recycling the magnesium ammonium phosphate crystal obtained in the step (2), drying the magnesium ammonium phosphate crystal, feeding sodium hydroxide powder into the magnesium ammonium phosphate crystal, carrying out heating pyrolysis, and feeding a pyrolysis product into the waste water to obtain the ammonia by means of circulating sedimentation; and (4) feeding the pyrolysis product obtained in the step (3) into acidic liquor to carry out acid pyrolysis once after the step (1), the step (2) and the step (3) are carried out twice and five times, and feeding an acid pyrolysis product into the waste water to obtain ammonia by means of circulating sedimentation. By the aid of the method, the problem of over high medicament cost of a magnesium ammonium phosphate method is solved, and the difficult problem that ammonia and nitrogen removal rate is reduced along with increase of ammonia circulating sedimentation frequency of magnesium ammonium phosphate is also solved.

Description

technical field [0001] The invention belongs to the field of wastewater treatment, and more specifically relates to a high-concentration ammonia-nitrogen wastewater circulation treatment method, which can efficiently remove ammonia nitrogen in wastewater and is suitable for treating high-concentration ammonia-nitrogen wastewater such as in the fertilizer industry. Background technique [0002] In recent years, the magnesium ammonium phosphate crystallization ammonia precipitation method has been extensively studied. Magnesium ammonium phosphate crystallization method achieves the purpose of removing ammonia nitrogen by adding magnesium salt and phosphate to high concentration ammonia nitrogen wastewater to form ammonium magnesium phosphate crystals with ammonia nitrogen in the wastewater. Magnesium ammonium phosphate is a good slow-release fertilizer. While removing ammonia nitrogen from wastewater, the precipitated product can also be used as a resource. However, the high ...

Claims

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Application Information

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IPC IPC(8): C02F1/58
Inventor 任洪强余荣台耿金菊许柯
Owner NANJING UNIV
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