Method for processing acidity ammonium nitrogen wastewater in fertilizer plant by using membrane separation

Abstract

The present invention discloses a method to treat acidic ammonium and nitrogen wastewater of chemical fertilizer plant by use of membrane separation. The method includes the following methods: a, the wastewater after oil separating is led into a solid-liquor separating device and the solid residue separated out is recycled; the wastewater is let into a colloid separating device to be carried out microfiltration and hyperfiltration treatment; b, the wastewater after being treated is pressed into a first grade reverse osmosis membrane component through pressurization by high pressure pump to carry through concentration, if the electrical conductivity is more than 13ms / cm, then the wastewater is sent back to an ammonium phosphate production department; if the electrical conductivity of the concentrated water is less than 13ms / cm, then the wastewater returns to a second grade reverse osmosis membrane component to carry through desalting. The concentrated water with a electrical conductivity less than 13ms / cm returns to an inlet of the first grade reverse osmosis membrane component to permeate to the freshwater of the second grade reverse osmosis membrane component and discharge. The present invention has the advantages of low energy consumption, low chemical reagent consumption and no secondary pollution. And simultaneously during the wastewater treatment, the present invention realizes the recycling of valuable components like nitrogen and phosphorus, etc.

Description

technical field [0001] The invention relates to the field of environmental protection, in particular to a treatment method for fluorine-containing or non-fluorine-containing high-concentration ammonium nitrogen wastewater generated during the production of chemical fertilizers. Background technique [0002] The chemical fertilizer industry is one of the important pillar industries in our country and occupies a very important position in the national economy. However, in the process of fertilizer production, it is inevitable to produce high-concentration ammonium-nitrogen wastewater that is difficult to treat. Although ammonium nitrogen is currently used as a secondary pollutant for pollution control in the country, due to the existence of ammonium nitrogen in wastewater, a large amount of ammonium nitrogen is discharged into rivers, lakes and even oceans, resulting in excess nutrients in the water environment and eutrophication of water bodies, thus cause algae pollution. ...

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Problems solved by technology

[0007] 3. Blow off method. In addition to high energy consumption and alkali consumption, the disadvantage of using blow off technology to deal with ammonia nitrogen is to transfer ammonia nitrogen from the liquid phase to the gas phase. If there is no corresponding recovery technology, it will easily lead to secondary pollution of the atmosphere. secondary pollution

[0009] 5. Biological treatment. There are still difficulties in the treatment of high-concentration ammonia-nitrogen wastewater: (1) In order to make microorganisms grow normally, the reflux ratio must be increased to dilute the original wastewater; (2) The nitrification process not only requires a large amount of oxygen, but also reacts Nitrification requires a large amount of carbon sources, and it is generally believed that COD / TKN is at least 9

For the biological denitrification treatment of high-ammonia-nitrogen and low-carbon source wastewater in the coking industry and chemical fertilizer industry, it is necessary to add more additional carbon sources, which increases the treatment cost

[0010] 6. Membrane bioreactor treatment of ammonia nitrogen wastewater will solve some problems existing in the traditional activated sludge method, but there is no better solution to the problem of membrane fouling

However, the problem with this method is that adjusting the pH requires a large amount of acid and alkali, which increases the processing cost.

But this method has following problem to exist: under the comparatively bad condition of industrial waste water, the culture of microorganism and breeding problem;

[0013] In summary, there is currently no feasible method for the treatment of high-concentration ammonium-nitrogen wastewater from phosphate fertilizer plants, mainly because the composition of wastewater is complex, and there is no method that can effectively remove multiple impurities in wastewater at the same time

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