| Polycyclic aromatic hydrocarbons are of great concern in the environmental science area because of their toxicological effects and widely occured in environment But so far the studies on its chlorinated derivatives are still very limited.Structurally,chlorinated PAHs(Cl-PAHs)are hybrids of dioxins and PAHs.Because PAHs and Cl-PAHs are chemically similar,they may be formed concurrently during combustion.Cl-PAHs which are suspected of having stronger toxicities,for carcinogenic or mutagenic effect,are becoming a new class of high-risk organic pollutants Nevertheless,prior to the present studies,distribution and environmental effects of Cl-PAHs in environmental media are not clear.Thus carrying out basic research on analytical method,environmental behavior and degradation of Cl-PAHs has very important significanceIn this thesis,the determination methods of 6 Cl-PAHs in the surface water and soil were developed,vital baseline information on Cl-PAHs'distribution in and around the Nanjing chemical industrial park was provided and the influential factors of biodegradation of chlorinated anthracene by phanerochaete chrysosporium were explored.The main work of this paper is as follows:1)A solid phase extraction(SPE)coupled with gas chromatography-mass spectrometry(SPE-GC-MS)method was developed for the determination of 6 Cl-PAHs.Analysis was done by internal calibration performed with GC/MS.The capillary column was an Agilent Technologies DB-5MS with the following temperature program from 80?(1 min)to 200? at 25?/min,then from 2000 to 213?(1 min)at 1?/min.The target compounds in water samples were concentrated by Poly-Sery HLB SPE cartridge,with the in-flux rate of 2 ml/min,and then eluted by 6 mL of n-hexane and dichloromethane(4:1).Good linearity could be observed in the range of 1 to 1000 ng/L of CI-PAHs,with correlation coefficients varying from 0.9952 to 0.9995.The limits of detection and limits of quantification were 0.013 to 0.592 ng/L and 0.043 to 1.971 ng/L,respectively.The recoveries for spiked samples of pure water were ranged from 77.8%to 105.4%,with the standard deviations less than 9.37%,except for 9-ClFle.2)An accelerated solvent extraction(ASE),gel permeation chromatography(GPC),SPE coupled with GC-MS method was developed for the determination for 6 Cl-PAHs in the soil.The optimised ASE parameters used for the final method were as the following:dichloromethane/n-hexane(v/v,1:1),four extraction cycles at 100?(5 min heating)and 10 min static time.After the extraction cycle,each extraction cell was flushed with solvent(90%of the cell volume),purged with nitrogen(110 s)and the extracts were transferred to standard collection vials for clean-up.The collected solvent volume was about 30mL and the extraction time was about 40 min per sample.The obtained extract was passed through GPC,and the fraction between 25 and 35 minute was collected.Further cleanup by SPE was conducted.The relative recoveries for the studied Cl-PAHs were ranged from 64.1%-117.6%with the standard deviations less than 12.0%when the spiked concentration was at 20 ng/L.when the concentration at 200 ng/L,the relative recoveries were ranged from 59.1%-105.3%with the standard deviations less than 9.81%.The limits of detection and limits of quantification were 2.6-25 pg/g and 8.7 to 83.6 pg/g,respectively.3)Vital baseline information on Cl-PAHs distribution was investigated in and around the Nanjing chemical industrial park.We collected water samples from Chuhe river,sewage treatment plant and chemical industry in chemical industrial complex.Total concentrations of Cl-PAHs were found to be 23.59-106.37 ng/L.The ?Cl-PAHs in Chuhe were lower than the concentrations in chemical industrial complex samples.This suggests that chemical production contributes to the formation of Cl-PAHs.The results of soil samples showed that the occurrence of IECl-PAHs in soil was 2 to 3 orders of magnitude higher than the concentration measured in water.Total concentrations of Cl-PAHs were found to be 12.77-61.10 ng/g in soil samples.we also found that chlorinated anthracene concentrations were lower than chlorinated fluorene,but the scope of pollution was wider.4)The influential factors of biodegradation of chlorinated anthracene by phanerochaete chrysosporium were explored.And the best condition to degrade Cl-Ant was pH 4.5,temperature 35,inoculum about1×105 ?/ml,initial concentration of Cl-Ant 2?g/ml.The experimental results showed that the biodegradation rate of 9-ClAnt and 9,10-Cl2Ant could achieve 96.45%and 92.83%respectively.The degradation kinetics equations were:9-CIAnt:y=0.032+0.58e(-0.37x+0.53)R2=0.9829,10-Cl2Ant:y=0.069+0.56e(-0.30x+0.51)R2=0.979.Through identifying intermediate products of Cl-Ant,5 stable metabolites were obtained.According to the appraisal of intermediate products,the final biodegradation pathway for Cl-Ant was inferred... |
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