Study On Blowing Reagent Accelerating Applied To Stripping And Absorbing Wastewater Containing Ammonia By Coal Gas

With the high-speed development of agricultural and industrial production and the rapid improvement of people's living standard, the emission of nitrogen compounds increase rapidly. Ammonia-nitrogen becomes the one of main pollutants causing water eutrophication, especially high concentration ammonia nitrogen wastewater is more serious to pollution of water. The main water pollution source of steel industry comes from coking waste ammonia in which the emission concentration of ammonia-nitrogen is over-standard, so the removal of ammonia-nitrogen from waste ammonia have became the environmental protection subject to be solved nowadays.At present, in the treatment techniques of ammonia-nitrogen wastewater no one can handle high-concentration ammonia-nitrogen wastewater economically and effectively but can't produce secondary pollution. According to the situation that ammonia-nitrogen emission of coking wastewater can't reach the standard, this paper uses"coal gas stripping and adsorption process"to treat high-concentration ammonia-nitrogen in coking wastewater. This way is a new ammonia-nitrogen removal technology on the basis of blow-off method and introduces the third component(surfactant)as blowing-off promoter, which is economical-effective and no secondary pollution, and was seldom reported in home and abroad.The course of blowing-off promoter cooperated with cooperating coal gas stripping and adsorption process to treat ammonia-nitrogen in coking wastewater was belongs to the course of gas-liquid mass transfer and the main factors influencing ammonia-nitrogen removal rate were the temperature of wastewater, the pH of system, the flow of coal gas, the time of blowing-off, the dosing quantity of blowing-off promoter and so on. The synergistic mechanism of third component(surfactant) as blowing-off promoter could improve the removal rate of ammonia-nitrogen by changing interfacial properties, increasing the area of gas-liquid mass transfer, promoting interfacial turbulence and Marangoni effect.Then,according to orthogonal design scheme, this paper studied on the static and dynamic experiments of blowing-off promoter cooperated with coal gas stripping and adsorption process to treat ammonia-nitrogen in coking wastewater. By the static experiments it got that: under the uniform conditions of the wastewater temperature, the system pH, the coal gas flow, the blowing-off time, the removal rate of ammonia-nitrogen could increase to 99% from 96% by the addition of a little surfactant, which proved that the synergistic effect of blowing-off promoter in coal gas stripping and adsorption process was very obvious. Meantime, when the the amount of blowing-off promoterⅠwas 0.0035g/L and the the amount of blowing-off promoterⅡwas 0.00030 g/L the removal rate of ammonia-nitrogen both can reach overt 99% and the content of ammonia-nitrogen in wastewater after treatment could both be below 50 g/L that could satisfy the biochemical processing requirements.By the dynamic experiments simulating industrialization it got that: when no synergistic effect of surfactant, the important order of relevant factors influencing the removal rate of ammonia-nitrogen was T>t>pH>Q, and the best operating condition was T=80℃, t=180min, pH=10.6, Q=13.0m3/h, in which the removal rate of ammonia-nitrogen was 90.45%.Meanwhile, under this best operating condition through introducing the surfactant as blowing-off promoter cooperated with the coal gas stripping and adsorption process to treat ammonia-nitrogen in coking wastewater, the removal rate of ammonia-nitrogencan increased to 95% from 90.45%, the removal rate of phenol increased to 46.08% from 29.35%, but the removal effects of COD was not obvious. The concentration of effluent ammonia-nitrogen was 198 mg/L that can satisfy the demands of the subsequent biochemical treatment In this study because the addition of surfactant was very little and the synergistic effect of surfactant was remarkable, it had proved that surfactant as blowing-off promoter cooperated with the coal gas stripping and adsorption process to treat ammonia-nitrogen in coking wastewater was a high effective, economy and environmental method.