The Study On Biodegradation Of Aniline And P-nitroaniline In Biological Aerated Filters

Aniline compounds are the product of many processes or widely used as rawmaterials in many industrial products. Aniline and p-nitroaniline which are widelyused,generally polluted and greatly harmful are both the United States’ and China’spriority controlled pollutants. How to effectively control the pollution to theenvironment by aniline compounds have become a common concern.This experimentation uses biological aerated filter (BAF) to biodegradate anilinewastewater and p-nitroaniline wastewater which are both by artificial preparationrespectively,and focuses on the removal characteristics and relevant impact factors. Inaddition,A dynamics mathematical model based on the degradation of aniline andp-nitroaniline is put forward, and the model coefficients are determined by theexperiments.Finally, the microbial morphology of filter are studied preliminary.Composite inoculation hanging membrane method are effective and fast for bothBAF reactor biofilms. Under the condition of this experimental,degradation efficiencyof the two substances are increaseing as increase of the EBCT.In different EBCT,theremoval of two organic substrates are mainly concentrated in the lower filtercolumn,and the degradation efficiency is decreasing with the filter higher up thecolumn. The volumetric loading rate of BAF which degradate aniline or p-nitroanilinedecreases with the indecrease of the EBCT. Gas-water ratio has a great impact on theremoval of aniline and p-nitroaniline.Neither too large gas-water ratio nor too smallgas-water ratio is helpful for the removal of aniline and p-nitroaniline.With the effectof degradation and economic factors concerned, and in the stable situation ofEBCT,gas-water ratio,temperature,the greater the substrate influent concentration,thesmaller the dissolved oxygen concentration is,and poorer the removal efficiencyis.Besides,too much concentration of influent water will produce toxicity whichinhibits micro-organisms.The kinetic model for the removal of Aniline and p-nitroaniline by the BAFwhich use this ceramic filter were:aniline:S=S0exp(-0.00583u-0.7396h); p-nitroaniline:S=S0exp(-0.0011u-1.4663h).The SEM-images showed that the growth of manymicroorganisms with much species attached to both the surface and internal of ceramicwhich forms a network structure intertwined by the extracellular polymeric duringmetabolism. Ecosystem which is Abundant species,structural integrity,function and stability present in the filter column.