Atmospheric Pressure By Air Stripping And Catalytic Oxidation Of Gas Phase Ammonia Series Deal With The High Concentration Ammonia Wastewater

Ammonia nitrogen is one of the important oxide consumable pollutants in water, and one of the key reasons of eutrophication. With the agriculture and industry development, the pollution sources of wastewater containing ammonia nitrogen become more and more comprehensive, and does the amount of discharge, which are from all types of industrial wastewaters, such as, ammonia machining plant, metallurgical plant and petroleum refinery plant wastewater and landfill leachate, besides domestic wastewater and animal excrement. The most important source of wastewater with high concentration of ammonia nitrogen is the industry. However, how to deal with this wastewater is a puzzle in China's wastewater-control field. Therefore, seeking the effective and economical method to dispose it is an important task for environment researchers.In this thesis, based on the stripping method, the author adopts gaseous catalytic oxidation to remove ammonia as the following process. Firstly, in this experiment, ammonia is snipped from water to air under the atmospheric press, while air is carrier and oxidant. Secondly, in the range of reaction temperature, ammonia is oxidized to NOx, N2, H2O and NxHy etc. By controlling temperature, the chief oxide are N2 and H2O. The concentration of ammonia nitrogen in wastewater is 1024mg/L. The four kinds of catalysts, laden amount of active and secondary components being about 30% and 50%, are cranked out by mixing and deposition method apart.Though the experiment, it can be found mat:(1)the volume and concentration of ammonia stripped from wastewater could be regarded as ration, by the conditions of air flow<2L/min, pH=14, water temperature=98C; (2)the activity of the catalyst which contains 50% active and secondary components made by deposition method is highest, while its reaction temperature is lowest and its selectivity of producing N2 is comparatively well, under the optimal conditions of reaction temperature=500C and airspeed=6000h-1, when backfill volume of this catalyst is 10ml;(3)when the aforementioned catalyst is used under the optimal conditions, the concentration of NHs-N in wastewater can be cut down from 1024mg/L to 34mg/L after 120min, while the elimination quotiety of it is about 96.7%, and the transformation quotiety of NH3 is about 95.7%, with the concentration of remnant NH3 andNO being 139ppm and 360ppm respectively, and the producing quotiety of N2 is about 88.4%; (4)the reaction of ammonia catalytic oxidation abides by the mechanism of SCR, and it is controlled by chemistry kinetics.The aim of this study is to attempt a new method to dispose the wastewater with high concentration of ammonia nitrogen, and to discuss its feasibility, reaction mechanism and chemistry kinetics. Based on that, the study can proceed further in future.