Treatment Of High Concentrations Of Ammonia & Nitrogen Wastewaterin Coke-Oven Plant With Blow-Off Method

In the outline of the national economic and social development of "The 12th Five-Year Plan", proposed the target of ammonia nitrogen emissions by 10% clearly.As a new binding index.ammonia nitrogen emission reduction systems and measures needed to explore in practice.The ammonia nitrogen in the ammonia nitrogen wastewater treatment as the major pollutants appear very high frequencies in the seven major river systems, ammonia nitrogen pollution is the national pollution problems.In the 12th Five-Year planning proposals that passed in the Fifth Plenum of the 17th CPC held in October of this year, ammonia nitrogen has become binding control index of the nation's major water pollutant emissions after COD.Coking wastewater has high ammonia nitrogen concentration, is a kind of industrial wastewater biodegradable harder.At present, treatment to Coking wastewater especially the main source of coking wastewater-supeus ammonia, is using vapor stripping process to denitrification in the most domestic enterprises,then turn to conventional activated sludge process. Discharge of wastewater in this way is hard to meet the increasing requirements of environmental protection, and exists the situation of ammonia nitrogen exceeds bid badly.The ammonia nitrogen removal of coking wastewater has become one of the main problems exists in Coking industry wastewater treatment. This paper reviews current ammonia nitrogen wastewater treatment technology, according to status that Coking wastewater treatment process and ammonia nitrogen is substandard, for pretreatment to Coking wastewater by striping method, combine the biochemical method, in order to solve the problem of ammonia nitrogen exceeds bid.This experiment used method of air striping to remove ammonia nitrogen of clad steel Coking plant's supeus ammnonia. Wastewater concentration can up to 8072mg/ L,test studies some factors' effects of ammonia nitrogen removal,such as reaction temperature, pH, gas to liquid ratio, reaction time and so on. obtains the best reaction conditions, and discusses the possibility of application in industry.Experimental results show that:(1) air striping method can effectively remove the ammonia nitrogen of coking wastewater, the removal rate can reach more than 95%.(2)based on the analysis of the orthogonal experiment obtained that the main influence factors are:pH, reaction temperature T, stripping reaction time t, gas to liquid ratio. (3) through orthogonal and single factor experiments,come to the conclusion that the optimum reaction conditions removing ammonia nitrogen by air stripping and adsorption method are pH=10.4, temperatureT=70℃, gas to liquid ratio is 6000, reaction time t=120min. (4) the best removal effect can be achieved when the temperature is 70℃.match with 70～80℃of raw water of normal production, so it has a good economy.