Co-metabolism Of Aniline Aerofloat With Different Substrates In Flotation Wastewater

The flotation wastewater in mine was great volume and more kinds of pollutants, which was most outstanding feature, organic matter of which was nonbiodegradable, and the characteristic brought great difficulty for its recycling. In this paper, the co-metabolism characteristics of aniline aerofloat were researched with different substrates and different ratios with substrates in SBR(Sequencing Batch Reactor) system. It obtained the best co-metabolism condition of single and mixed substrates with aniline aerofloat, and also simulated the kinetic equation of its biodegradation. The intermediate materials were analysised with HPLC(High Performance Liquid Chromatography) and GC-MS(Gas Chromatograph Mass Spectrometer), experimental results demonstrated as follows:(1)In laboratory conditions, the biological sludge of secondary sedimentation tank in sewage treatment plant had been acclimated by artificial rearing in SBR, the flotation wastewater simulated with aniline aerofloat as main organic pollutant, and the acclimated SBR systems had a high biodegradation efficiency; The SBR systems were acclimated by reducing the concentration of glucose and incressing aniline aerofloat during the cultivation. Finally, the concentration of glucose and aniline aerofloat in inflow were Omg/L and200mg/L respectively. And that the systems could operate steadily, the COD and aniline aerofloat degradation ratios could attain64.3%and93.4%respectively, It shown that the cultivation had finished;(2) From the higher aniline aerofloat degradation ratio than COD’s. we could know that the degradation ratios of COD and aniline aerofloat were inconformity. This appearance would be caused by intermediate created during the biodegradation of aniline aerofloat. The process of biodegradated aniline aerofloat in SBR systems had been finished in2hours, it could show us from the systems degradation curve graphs. And the concentration of COD and aniline aerofloat gradually tended to invariant. The period time of oxidation reaction in SBR systems could confirm on3hours in consideration of the sludge impact charge and the delay of monitor;(3)The concentration of aniline aerofloat remained unchanged at200mg/L and added single co-metabolism substrate, we researched the ratios of aniline aerofloat to substrate; the promoting degradation was:sucrose>sodium acetate> glucose> amylum> Vitamin C.When the quality ratio of aniline aerofloat to substrate was1:1,the degradation efficiency of aniline aerofloat was highest, the COD in effluent was70mg/L, when co-metabolism substrates was sucrose, the removed ratio of COD was87.3%, the concentration of aniline aerofloat in effluent was just3.7mg/L, and the degradation ratio reached98%, it was very advantageous;(4)The co-metabolism biodegradation had been researched by adding different mixed co-metabolism substrates in a unchanged quality ratio of co-metabolism substrates to aniline aerofloat. The results shown that sucrose and sodium acetate as the mixed co-metabolism substrates was the best one, which concentration of COD and aniline aerofloat in effluent were84.7mg/L and13.55mg/L, and also the degradation ratios were84.6%and93.23%respectively;(5)The monitor results of co-metabolism degradation were collected in SBR system, with sucrose as single co-metabolism substrate,sucrose and sodium acetate as the mixed co-metabolism substrates, the1:1adding ratio, for that, the kinetics model had been established by improved MONOD equation form. The single co-metabolism substrate biodegradation kinetics parameters were v’max=-40.81633mg/(L·min), Ks=-1357.6736mg/L,R2=0.9027,and The mixed co-metabolism substrates biodegradation kinetics parameters were v’max=-17.4216mg/(L-min), Ks=-684.6515mg/L, R2=0.8121. The results shown that the co-metabolism biodegradation kinetics parameters were identical preferably with the physical truth, and it were applicative with the co-metabolism systems;(6)There were two main intermediate materials produced during the co-metabolism biodegradation of aniline aerofloat, which inferred from the results of HPLC analysis to the different period of SBR system. The main probable intermediate materials could be nitrosobenzene due to the results of GC-MS analysis to the intermediates. According to the conditions of SBR systems, with the addition of the results of HLPC and GC-MS analysis, we proposed the mechanism of aniline aerofloat biodegradated.