Study On Typical Influencing Factors Of Non-Aqueous Pollutants In SVE Technology

With the concept of environmental geology being put forward and strengthened,the technology of SVE?Soil Vapor Extraction?for the remediation of non-aqueous soil pollution has developed rapidly home and abroad,and the related technology of SVE enhancement and improvement has been constantly updated,but there are still shortcomings in basic research.In this paper,the primary and secondary effects and significance of the main influencing parameters are studied when applying this technology.Nine groups of orthogonal experiments with three levels and four factors are designed.The repair process of each group of model experiments is studied in detail.The first-order kinetic reaction equation is fitted for the concentration of pollutants in different periods of each group of experiments.It is found that R² is above 0.9,which meets the requirement of simulation.In this paper,the primary and secondary effects and significance of the main influencing parameters are studied when applying this technology.Nine groups of orthogonal experiments with three levels and four factors are designed.The repair process of each group of model experiments is studied in detail.The first-order kinetic reaction equation mathematical model is fitted for the concentration of pollutants in different periods of each group of experiments.It is found that R² is above 0.9,which meets the requirement of simulation.According to the requirements,the specific information of each group of experimental process and the evaluation of fitting degree were obtained,and on this basis,the half-life of each group of experimental pollutant concentration was obtained.On the basis of the data obtained from orthogonal experiments,the range analysis of nine groups of experiments was carried out,and the primary and secondary effects of each factor on the removal rate of experimental indicators were judged as follows:time>temperature>pollutant concentration>exhaust flow rate.Through variance analysis and significance test,F_A>F_B>F_D>F_0.01>F_C>F_0.05.05 was obtained,and the time factor was the most significant,followed by temperature and pollutant concentration.Finally,it is the pumping flow rate;F_A>F_B>F_D>F_0.01,the time,temperature and pollutant concentration are highly significant;F_0.01>F_C>F_0.05,it is found that the influence of the pumping flow rate is significant,it is known that these four factors have significant impact on the removal rate in SVE technology,and the results of range analysis are verified.Through multiple comparisons,it is also found that the differences among the average indicators of time,temperature,exhaust flow rate and pollutant concentration are extremely significant and significant.Again,it is verified that the optimal level combination of each factor is A₁B₂C₃D₁.The comprehensive optimal combination is:time:180 min,temperature:20?,exhaust flow rate:6000 ml/min;pollutant concentration:2%,that is,experiment No.5.