The Application Of Environmental Emergency Monitoring Instruments On Stationary Emission Pollution Incident And Its Source

With the rapid development of China’s society and economy,environmental problems is more and more important,and environmental pollution incidents happen frequently,especially with the increasing proportion of air pollution incidents.Emergency response on-site monitoring of the air pollution has become a key work of atmospheric environmental risk management.It has become the significant work the building of environmental monitoring capacity to study and develop rapid response monitoring technology of air pollutants.In this paper,the emergency monitoring methods including the portable gas chromatography-mass spectrometry(GC-MS)analyzer and the portable fourier transform infrared(FTIR)spectrometer were compared with those laboratory standard analysis methods.Results indicated that the precision of BTEX(benzene,toluene,ethylbenzene and xylene)by the portable GC-MS analyzer is 6.3%～9.6%,with the accuracy of 95.7%～106.6%while the precision and accuracy by the standard method in lab is 0.44%～1.92%and 98.90%～101.37%,respectively.The precision and accuracy of methane and propane in air by the portable FTIR spectrometer is 0.7%～2.0%and 102.1%～111.1%,respectively,while 0.6%～0.7%and 101.1%～104.2%,respectively,by the laboratory standard analysis methods.The results showed that although the precision and accuracy of the two methods used in emergency monitoring are slightly lower than those of laboratory standard analysis methods,the deviation within 20%is still acceptable considering that the portability of the emergency instruments.The results between the analysis of BTEX by the portable GC-MS analyzer and the laboratory analysis methods has a good correlation,with the correlation coefficient within the range of 0.990 and 0.996.The correlation coefficients of methane and propane between the portable FTIR spectrometer and the laboratory analysis methods are 0.994 and 0.995,respectively,which are both greater than the critical correlation coefficient under the significant level of 0.05,indicating that the results of emergency monitoring methods in this study are significantly correlated with the results of the laboratory analysis methods.The t-test method is used to analyze the consistency to the portable GC-MS analyzer and the standard methods for BTEX,and the results indicated that the T-value of ethylbenzene,styrene,o-xylene,1,2,3-Trimethylbenzene,1,2,4-Trimethylbenzene and 1,3,5-Trimethylbenzene by the portable GC-MS analyzer is between 0.039 and 1.568,less than T0.05(8)of 2.306,indicating that there was no significant difference between the analysis results of those air pollutants by the laboratory standard analysis methods.The T-value of benzene,methylbenzene and p/m-xylene is 3.346,4.874 and 2.415,larger than t0.05(8),indicating that there may be different between the analysis results of benzene,methylbenzene and p/m-xylene by the portable GC-MS analyzer and the laboratory standard analysis methods,so the uncertainties due to the difference of speices should be considered for its application and,if needed,other methods are needed to assist it.From the analysis of monitoring timeliness,the emergency monitoring methods are all on-site direct monitoring without transportation and storage of samples.The standard methods usually consist of sampling,transportation and preservation which usually need several hours after sampling and before analysis of samples.The 8-hour reduction experiments of methane,propane and BTEX collected by air pocket analysis were conducted,and the 8-hour reduction rate of methane,propane and BTEX by simulating various preservation conditions,was around 5.0%～10.5%.Those studies proved the timeliness advantage of the emergency monitoring methods of on-site direct monitoring.Based on the above research,with the test of the emergency monitoring instruments being relatively stable,and the data provided by the emergency monitoring methods relatively reliable,the use of emergency monitoring methods was introduced to establish the pollution characteristics of pollutants,continuous improvement of the contingency plan of the main enterprises,assist to reduce emission of volatile organic compounds,measure treatment efficiency of pollution control project of volatile organic compounds,assist to the laboratory standard methods for the qualitative aspects,deal with the current knotty environmental problems,and estimate the Ozone formation potential in the VOCs emission enterprises.