Method for decomplexing heavy metal ammonia complex in high-concentration ammonia-nitrogen wastewater

A technology for ammonia nitrogen wastewater and ammonia complexes, applied in the direction of water pollutants, chemical instruments and methods, multi-stage water/sewage treatment, etc., can solve the problem of difficult removal of heavy metals, achieve no secondary pollution, low treatment cost, The effect of good processing power

CN102942280AActive Publication Date: 2013-02-27BEIJING CYCLE COLUMBUS ENVIRONMENTAL SCI & TECH
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Patent Information

Authority / Receiving Office
CN · China
Current Assignee / Owner
Publication Date
2013-02-27

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Abstract

The invention relates to a method for decomplexing a heavy metal ammonia complex in high-concentration ammonia-nitrogen wastewater, which comprises the following steps of: adding an alkaline material into the high-concentration ammonia-nitrogen wastewater containing heavy metals, so that ammonium ions are converted into ammonia molecules and residual hydroxyl ions exist; and by controlling the flow and the pressure of steam input into a stripping tower, controlling the temperature distribution of the stripping tower, so that liquid is kept for a certain retention time in a certain temperature region in the stripping tower, the heavy metal ammonia complex is decomposed and the heavy metal ions are combined with the residual hydroxyl ions in the wastewater to generate precipitates. The method disclosed by the invention has an excellent decomplexing effect on the heavy metal ammonia complex, is simple to operate and has no secondary pollution.
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Description

technical field

[0001] The invention relates to a method for decomplexing complexes, in particular to a method for decomplexing heavy metal ammonium complexes in high-concentration ammonia-nitrogen wastewater and realizing simultaneous removal of metals and ammonia in water, belonging to the field of industrial wastewater treatment. Background technique

[0002] In the production process of chemical industry, metallurgy, battery, electroplating and other industries, a large amount of high-concentration ammonia nitrogen wastewater is often produced. The ammonia nitrogen concentration of this wastewater is greater than 1000mg / L, up to 100000mg / L, and it also contains high concentration of inorganic salts and heavy metals . Regarding the treatment of this type of wastewater, the effective treatment method is: first adjust the pH to alkaline, convert all the ammonia nitrogen in the water into the form of ammonia molecules, and then use the steam stripping method to transfer the ...

Examples

Embodiment 1

[0031] For copper-containing ammonia nitrogen wastewater, where the concentration of copper ions is 127mg / L and the concentration of ammonia nitrogen is 1722mg / L, the specific process is as follows:

[0032] 1) Add potassium hydroxide solution to the above wastewater to adjust the pH of the wastewater to 11, so that the ammonium ions in the wastewater are converted into ammonia molecules, and there are excess hydroxide ions;

[0033] 2) Put the alkaline wastewater described in step 1) into the stripping tower for treatment; control the temperature of the stripping tower by controlling the steam flow rate and steam pressure input into the stripping tower, so that the temperature of the tower kettle is 185 °C, and the temperature at the upper 10m of the tower kettle is The temperature is 175°C;

[0034] 3) Adjust the flow rate of the waste water through the spacing of the multi-stage trays in the stripping tower, so that it takes 12 seconds to pass through the 10m area described...

Embodiment 2

[0037] For the ammonia nitrogen wastewater containing molybdenum, the molybdenum ion concentration is 2129mg / L, the ammonia nitrogen concentration is 46003mg / L, the specific process is as follows:

[0038] 1) Add sodium hydroxide solution to the above wastewater to adjust the pH of the wastewater to 13.5, so that the ammonium ions in the wastewater are converted into ammonia molecules, and there are excess hydroxide ions;

[0039] 2) Put the alkaline wastewater described in step 1) into the stripping tower for treatment; control the temperature of the stripping tower by controlling the steam flow rate and steam pressure input into the stripping tower, so that the temperature of the tower bottom is 102°C, and the temperature at the top of the bottom 10m The temperature is 95°C;

[0040] 3) Adjust the flow rate of the waste water through the spacing of the multi-stage trays in the stripping tower, so that it takes 30 seconds to pass through the 10m area described in step 2); the...

Embodiment 3

[0043]For ammonia nitrogen wastewater containing nickel and cobalt, the concentration of nickel ions is 217mg / L, the concentration of cobalt ions is 60mg / L, and the concentration of ammonia nitrogen is 22500mg / L. The specific process is as follows:

[0044] 1) Add a mixed solution of sodium carbonate and sodium hydroxide to the above wastewater, and adjust the pH to 12. At this time, some cobalt carbonate and nickel carbonate precipitates are formed, and they are removed by a filter;

[0045] 2) Put the alkaline wastewater described in step 1) into the stripping tower for treatment; control the temperature of the stripping tower by controlling the steam flow rate and steam pressure input into the stripping tower, so that the temperature of the tower kettle is 115 °C, and the temperature at the top of the tower kettle is 10m The temperature is 106°C;

[0046] 3) Adjust the flow rate of waste water through the spacing of the multi-stage trays in the stripping tower, so that the ...