Study On Removal Of NH₃-N In Coking Wastewater With Stripping And Adsorption Process

With the development of modern industry, industrial water consumption sharply increases and is occupied 85% of the total water consumption; at the same time, the problem of water pollution becomes more and more serious, it has been very difficult for human because of the exhaustion of water resources. It is the best way to improve the condition by increasing water utilization and lowering water pollution. But components are complex in coke plant wastewater, in which contains high concentration of ammonia nitrogen and a number of toxic and refractory organic compounds, and great changes happened usually to water quality and water flow, is one kind of more difficult living things degradation industrial sewage. At present, to treat coking waste water, especially treat the main source of coking waste water-surplus ammonia water, great majority enterprise all adopt steam stripping law to remove ammonia, and then shifts to routine activity sludge law again. The waste water index that law discharges is difficult to satisfy the environmental protection request improving gradually, and all existence that the ammonia nitrogen goes beyond standard gravely condition. Removing ammonia nitrogen in coking waste water becomes one of the primal problems mounting existence in coking industry sewage treatment.This text has been summed up the ammonia nitrogen waste water treatment technology, the current situation specifically for the available coking waste water treatment handicraft and ammonia nitrogen doesn't reach the standard, adopts blow-off law pretreatment, then combine with biochemistry law, in order to solve the difficult problem of the ammonia nitrogen going beyond standard.The experiment adopted"stripping and adsorption by air"and"stripping and adsorption by coke gas"to remove ammonia nitrogen of Wuhan steel coking surplus ammonia water, studied the reaction temperature, pH value, the discharge of coal gas Q, NH3 content of the coal gas C and the time of stripping t, got the best condition of the experiment, and discussed the possibility applying to industry.The experiment result was indicated:"air stripping and adsorption"and"gas stripping and adsorption"were able to have an effect getting rid of waste water, but"air blow-off and adsorption stripping"being able to arouse atmosphere , so we didn't use it; the best condition by"the coal gas Blow-off and adsorption stripping"was: T=80℃,pH= 10.2, Q=5L/min (air-liquid ratio was 3000:1), t=120min , C=0 L/min; the coal gas stripping and adsorption didn't cause environmental pollution combining with ammonium sulfate process and A2/O law , and had good economy, ammonia nitrogen index could accord with the standard of the country when the effluent had been treated by bacteria.