Bio-reaction Dynamics Study On SR-A Process Disposing Coking Wastewater

SR-A, which is abbreviation of SHARON-ANAMMOX, is a new kind of biological denitrification processes combined by nitrous nitrification and anaerobic ammonium oxidation reactions. The literatures appeared seldom on such technology's application of disposing the coking wastewater.The nitration dynamics models of ammonia nitrogen were focused on in the present paper to study the disposing processes of coking wastewater with SR-A methodology. On the basis of such models, the influences of several factors on the rates of nitrous nitrification were discussed. However, the influences on the rates of anaerobic ammonium oxidation were also concerned in the anaerobic ammonium oxidation reactor. And the optimum pH values were calculated theoretically.On the basis of the complement of microorganism cultivation and domestication, the promotion and operation circulation of nitrous nitrification reactor and anaerobic ammonium oxidation reactor were achieved successfully. From the abundant experimental data, the Lawrence-Mc Carty model was proved as the theoretical model to describe the nitrification process of ammonia nitrogen. And several dynamic parameters were gained, viz. v_max =2.55mg NH₄⁺-N? mg VSS^-1?d^-1, K_s=395.8mg NH₄⁺-N·L^-1, Y=0.1898 mg VSS ? mg NH₄⁺-N^-1, Kd=0.0336 d^-1.The effect and inhibition relations between the anaerobic ammonium oxidation rates and several factors were concerned, such as temperatures and values of pH and ammonia-nitrogen and nitrite-nitrogen concentration. The calculation results indicated that the rate of anaerobic ammonium oxidation reaction reached the theoretical maximum while the value of pH was equal to 7.86. Based on the model of Andrews, the reaction rate maximums of ammonia nitrogen and nitrite nitrogen were gained respectively, 238.10 mg NH₄⁺-N?gVSS^-1? d^-1and 121.95 mg NO₂^--N?gVSS^-1?d^-1. And their inhibition constants were 201 mg·L^-1 and 185 mg·L^-1. Aaccording to Arrhenius formula, the characteristic coefficient temperature has been determined, which is equal to 1.236.After running through the reactors of nitrous nitrification and ananerobic ammonium oxidation, the removal efficiencies of ammonia nitrogen, chemical oxygen demand and total nitrogen reached, 73.38%, 84.6% and 66.7% respectively.