Study On In-situ Remediation Of Simulated Groundwater That Is Polluted By High Concentration Nitrobenzene

Nitrobeneze,is widely applied in the chemical industry as the elementary material,mainly in dyeing,spice,pesticide and detonator.With the swift and violent development of the refinement industries,especially the development of printing, dyeing and dope,the demand of the nitrobenzene is gradually increasing which results in more nitrobenzene into the environment,so it needs the effective method to deal with the environmental harm which is caused by liquid waste that contaminated by the nitrobenzene.At present,most manufacture technics drop behind,low productivity,and the side reaction is complex,especially the environment is seriously polluted by the waste water,these are the no time to delay problems that the country have to deal with.Now,in domestic and overseas,there are three mainly methods for the nitrobenzene-degradation:physical,chemistry and microbe.In chemistry,with the deoxidization of the zero valent iron or the mixture of iron and other metals,the degradation is all right;in microbe,the effect is fine to do with low concentration nitrobenzene with the degradation of microbe.However,the study about the microbe associated with the chemical are little,so this paper simulates the surroundings of the underground where the groundwater is polluted by nitrobenzene of high concentration,then uses the PRB(together with the chemical and microbial methods)to degrade the nitrobenzene,the degradation is good.Through domestication and culture,a bacterial strain 7#,which was able to grow on common culture with aniline when the aniline concentration below 5500mg/L,was isolated from the activated sludge from the drain of Jilin city. The optimum temperature and pH for its growth and aniline degradation were 30℃and 7.0 respectively,but after low temperature domestication,the degradation rate at 10℃was close to 30℃.It didn't get obvious restraint when the concentration of aniline below 400mg/L.At 10℃,the aniline-degradation rate can arrive at 89.14% when the culture time was 60 hours in tactless liquid with aniline of 200mg/L,and the degradation was accorded to the second-order kinetics.Through the experiment of physiological and biochemical character and the identify by Biolog,the stain is identified as Pseudomonas.This paper simulates the surroundings of the underground where the groundwater is polluted by nitrobenzene(300mg/L)and aniline(82.67mg/L)in the trough in lab.It indicated that nitrobenzene can be transformed to aniline by the deoxidization of the zero valent iron,then aniline will be degraded by microbe.Together with the chemical and microbial methods,the system was stable after 10 days,the nitrobenzene and aniline can be well degraded that the removal rates can reach 99.4% and 99%.The effect is so good that it can offer some basis to demonstrational project on in-situ remediation where nitrobenzene concentration is high.