| The biological treatment technology of VOC waste gas has become a research hotspot in the world because of high purification efficiency, low charge of investment and run, and no secondary pollution etc. Up to now, many practical installations have been used in the West Europe, while there are only a few reports about its application in our country. Nowadays, a few experimental rearch of trickling biofilter treatment technology of VOCs waste gas have been carried out, there were a few related reports about trickling biofilter too, but the theoretical rearch was still within limits quite too. Within the reports about theoretical rearch in nowadays, a large per cent of theoretical bases of kinetic model were absorption biofilm theories. It is consider that VOCs was absorbed in liquidum-soild through diffuseness action and the carries gas and liquidum-soild. Furthermore, VOCs was resolved into CO2, H2O and orgnism. So, the working-out of kinetic model equation was became very complex and the accuracy was became very bad. This work was process based on the follow research: the microorganism is cultivated and domesticated. A visual experiment apparatus is designed and made firstly and then the two-phase flow friction characteristic and purification of toluene are studied visually. From the viewpoint of mass and heat transfer in engineering thermophysics, combined with biochemical reaction kinetics considering the limitation of oxygen, a new capillary model has been proposed to study the degradation characteristic of trickling biofilter. Based on the process of biodegradation mechanism of trickling biofilter and the Adsorption-Biofilm theory, a Kinetic model of Toluene biodegradation was set up. The important conclusions are drawn in the follows: 1.By escalate toluene concentration, a bacteria which had the ability to degradate toluene as a sole carbon source was screened and breeded from active sludge of Chongqing steel coking factory. The strain was further identified as Pseudomonas sp, whose best growth conditions was set as follows: the temperature was 35℃, pH=7, the first toluene added quantity was 20ul, the inoculate quantity was 5%. The best degradation conditions is: the temperature was 30-40℃, pH=7 and the inoculate quantity was 5%. 2.In laboratory conditions, from the experiment of degradation rate under different toluene concentration, it is found that with the increase of the toluene concentration of less than 300mg/L, the toluene degradation rate increase too, furthermore, the toluene degradation rate increase to 0.0735h-1 when the toluene concentration was 300mg/L. On the contrary, with the increase of the toluene concentration of more than 320mg/L, the toluene degradation rate was decreased nonlinerity, the toluene degradation rate decreased to 0.0479h-1 when the toluene concentration was 780mg/L. Based on the above experiment conclusion and the restraning mechanism of enzyme, a Kinetic model of the train Growth and Toluene biodegradation was set up under the restraning condition. The model equation is the follow: 3.8681774.121 1 80.135SS SqC= + C ×+ C The model equation is the follow: 0.2841237.3 1 238.1SS SuC= + C ×+ C.From the studying for model equation, it was found that a good pertinence was showed between calculated data and test data. 3. From the experiment of trickling biofilter treatment VOCs, several important conclsion was draw that with the increase of the gas flow rate, liquid flow rate, and the inlet toluene concentration, the purification efficiency decreases. 4. Based on the Kinetic model of laboratory conditions, combined with the Adsorption-Biofilm theory, a Kinetic model of Toluene biodegradation in trickling biofilter was set up. The model equation is the follow: ( ) ( )( )( )( )211110.1137640 7.75 0.122 121985.7 0.107 12163.8 1475.1 12163.8 550.6 121nn n nnnndCC C h P Qh Cdh Q P Qh CP Qh CP Qh C= ? ×+?? + + ? +×+??×???? ++ ?? ++???? From the compare of cell concentration value from experiment and formula calculation, it is found that the model equation was accord. |
