Method of separating and recovering ammonia from ammonia nitrogen wastewater

Abstract

The invention relates to a method of separating and recovering ammonia from ammonia nitrogen wastewater. The method comprises the following steps of: adding an excess vanadium-containing reagent to ammonia nitrogen wastewater; forcing ammonia nitrogen in the ammonia-nitrogen wastewater to be precipitated out in the form of ammonium salt by skillfully utilizing the common-ion effect generated by the vanadium-containing reagent, wherein the concentration of the ammonia nitrogen can be reduced to be less than or equal to 50mg / L; filtering to obtain ammonium enriched slag and a deaminated solution, and then adding a calcium-containing reagent or an iron-containing reagent to the deaminated solution so as to separate and recover the vanadium-containing reagent remaining therein, thereby causingV in the deaminated liquid to be less than or equal to 1mg / L; further decomposing the obtained ammonium enriched slag to obtain a product containing the vanadium reagent and ammonia (ammonium), thereby realizing the cyclic utilization of the vanadium-containing reagent in the ammonia-nitrogen wastewater treatment process and the resource treatment of ammonia-nitrogen wastewater to avoid the secondary pollution. The method has the advantages of simple process, simple operation, cleanness, environmental protection, economy, high efficiency and the like, and is suitable for industrial application of resource treatment of ammonia nitrogen wastewater.

Description

technical field [0001] The invention belongs to the fields of chemical industry and environmental protection, and in particular relates to a method for separating and recovering ammonia from ammonia nitrogen wastewater. Background technique [0002] Ammonia nitrogen is free ammonia (NH 3 ) and ammonium ions (NH 4 + ) in the form of nitrogen present in water. There are many sources of ammonia nitrogen in water. In addition to domestic sewage and landfill leachate, it also comes from the discharge of industrial wastewater such as iron and steel, oil refining, chemical fertilizers, leather tanning, petrochemicals, glass manufacturing, and feed production. Excessive ammonia nitrogen in the water body will lead to the proliferation of aquatic plants, blue-green algae and other organisms, destroying the ecological balance, causing a series of environmental problems, and seriously endangering ecological security. Under aerobic conditions, nitrosifying bacteria and nitrifying ba...

AI Technical Summary

Problems solved by technology

However, this method needs to add a large amount of phosphate and magnesium salt reagents, and also needs to add alkali to adjust the pH, the cost is high, and the regeneration method of the generated MAP is relatively harsh, which is not suitable for industrial applications.

[0009] In addition, it is well known that adding ammonia (ammonium) to vanadium-containing solution can form ammonium vanadate salt precipitation (ammonium vanadate, ammonium metavanadate and ammonium polyvanadate), but for a long time people have added ammonia (ammonium) to precipitate vanadium , and no one will add vanadium to precipitate ammonia (ammonium). This is because the ammonium vanadate salt has a certain solubility in water at room temperature, and the residual vanadium and ammonia nitrogen in the solution cannot directly meet the waste water discharge standard, and the chemical The products are relatively expensive, and simply adding vanadium to precipitate ammonia (ammonium) to treat ammonia nitrogen wastewater is technically unfeasible and economically uneconomical