Research On Disposing Wastewater With High Concentration Ammonia Nitrogen Using Ozone

High concentrations of ammonia-nitrogen wastewater is one of the most intractable industrial wastewater, the existence of ammonia brings difficult to the water treatment. Experts at home and abroad have been actively exploring solving programs or technical which have efficiency, small cost of investment, low operating costs, but this problem is not well resolved for various reasons or technical limitations at the present time. Because of its powerful ozone-oxidation and it does not produce secondary pollution, ozone is the ideal method to deal with the organic pollutants in water.This article describes the experimental process that using ozone generator with ozone to oxidize high concentrations of ammonia-nitrogen wastewater prepared by ammonium chloride, and on this basis adds hydrogen peroxide and chloride ions, hypochlorite ions in the ammonium chloride solution to observe them synergism oxidizing ammonia-nitrogen with ozone for the future application of high concentrations of ozone treatment of wastewater ammonia to lay the basis of certain experiments. At the same time introduced the ozone output of ozone generator, air gap solution of ammonia stripping experiment. The experiments used the highest ozone generator voltage 200 v, ozone production is 11.92 mg/min. Experiment configuration ammonia solution of ammonium chloride concentration of 2000mg / L and 500mg / L.The experimental results show that when simply using ozone in the case pH <10, the ammonia nitrogen removal rate increased with increased in pH and low concentration of ammonium chloride solution had high ammonia removal efficiency. pH =10 case, 100min,the removal rate reaches max, the highest nitrogen removal rate of high concentration of ammonium chloride solution reached 13.1%, and the highest nitrogen removal rate of low concentrations of ammonium chloride solution is 26%. In the removal of ammonia, 85～90% of ammonia nitrogen conversed into nitrogen and 5% into nitrosourea. At this point the ozone removal efficiency of ammonia nitrogen was not significant. Ammonium chloride solution is therefore to consider adding chemical agents synergistic with ozone oxidation.The chemical used in experiment is H₂O₂, sodium chloride, sodium hypochlorite. Sodium hypochlorite,H₂O₂ as the oxidant used, H₂O₂ decomposes in wastewater andcan be synergistic with ozone oxidation.Study abroad shows that, Br^- can be synergistic with ozone oxidation,but the too high concentration of Br^- is will be a large number of ozone-depleting and produce toxic by-products, so this experiment used the same family of Br^- with Cl^- observed experimental results.The experimental results show that, when in the ammonium chloride solution by adding H₂O₂, the ammonia removal rate with the addition of H₂O₂ receives a slight increase, when the H₂O₂ concentration doubled the nitrogen removal rate increased by 4～5%. pH = 10 cases, the ammonia nitrogen removal rate was maximum at 120min, the two concentrations of ammonium chloride solution the highest nitrogen removal rate reached only 30%. Removal of the same is not very obvious.In ammonium chloride solution by adding Cl^- and ClO^-, ammonia nitrogen removal rate improved significantly. At pH = 10 case, the solution adding Cl^-, in the former 60min on the ammonia removal rate is maximum, the two concentrations of ammonium chloride solution the highest nitrogen removal rate reached 62～65%,and ammonia nitrogen removal rate increased with the Cl^- addition increased;when added ClO^- to the ammonium chloride solution, at 80 min ClO^- concentration is 12%, the ammonia nitrogen removal rate of reached maximum, high concentrations of ammonium chloride solution the highest removal rate is 63.7%, low concentration of ammonium chloride solution the highest removal rate of 57%. From the results above we can see that Cl^- and ClO^- are ozone oxidation better synergy. After the final cost accounting, the use of sodium chloride as an additive to deal with the cost ofï¿¥0.18 per ton, the use of sodium hypochlorite as an additive costï¿¥0.30 per ton. Therefore more economical use of sodium chloride is applied to add the PH armacy.