Method for treating ammonia nitrogen in wastewater by using integrated process

Abstract

The invention relates to a method for treating ammonia nitrogen in wastewater by using an integrated process, and the method comprises a magnesium ammonium phosphate chemical precipitation process and a membrane treatment process and comprises the processing steps of collecting water, dosing, adjusting the pH (potential of Hydrogen) value, reacting, precipitating and filtering. The method has the technical characteristics that magnesium salt and phosphate are added during the dosing; a NaOH solution is added to regulate the pH to 8.5-10 during the adjustment; during the reaction, the wastewater retention time is greater than or equal to 30 minutes, the ammonia ion in the wastewater is fully reacted to generate magnesium ammonium phosphate precipitates and heavy metal ion is converted into hydroxide precipitates; the precipitation time is greater than or equal to 6 hours to realize solid-liquid separation during the precipitation; and the supernatant liquid enters a membrane treatment system, the reverse osmosis clear water can be directly discharged and the concentrated water returns to a water collecting tank or is subjected to nanofiltration. The method has the advantages that ammonia nitrogen-containing wastewater with various concentrations can be treated; heating is not needed in the treatment process; the ammonia nitrogen content in the effluent can meet the national first grade effluent standard; and the content of other pollutants such as heavy metals and the like in the effluent can be used for achieving the effluent standard. The method is suitable for treating low-biodegradability ammonia nitrogen-containing wastewater and the ammonia nitrogen-containing wastewater of factories without heat resources.

Description

technical field [0001] The invention belongs to the technical field of wastewater treatment, and in particular relates to a method for treating ammonia nitrogen in wastewater by using a combination process. Background technique [0002] With the increasing population and the rapid development of industry and agriculture, water pollution accidents occur frequently, posing serious harm to people and the environment. Many lakes and rivers cause water eutrophication due to excessive discharge of nitrogen and phosphorus, which seriously threatens human production, life and ecological balance. Ammonia nitrogen is one of the main factors causing water eutrophication. At present, incidents of heavy metal pollution in water occur frequently, which have a great impact on human health and safety. How to control ammonia nitrogen and heavy metal wastewater has become one of the main tasks in the field of water treatment, especially for the treatment of wastewater from mineral processing...

AI Technical Summary

Problems solved by technology

[0005] The present invention proposes a method for treating ammonia nitrogen in waste water using a combination process, the purpose of which is to use a combination process of chemical precipitation method + membrane treatment to overcome the shortcomings of the chemical treatment method that the ammonia nitrogen in the effluent is unstable and cannot be discharged up to the standard, and at the same time the membrane The advantages of treating low-concentration ammonia-nitrogen-containing wastewater, constant effluent quality, and high treatment efficiency are combined to reflect the advantages of the two processes and overcome the shortcomings of the two processes at the same time. It can achieve the standard discharge of ammonia nitrogen and heavy metals in the wastewater and meet GB8978- 96 "Integrated Sewage Discharge Standard" Class I Discharge Standard

Images