Study On Variation Of Temperature And Humidity In Biological Filtration System

With the improvement of the economic development and people's requirements of the living quality,the patience to the sensory pollution,such as noise and odor is more and more low,Odor pollution becomes the peoples' concentration.In the production process of petrochemical enterprises,many substances in raw materials,products,intermediate products are the malodorous substances.It can be emitted into the atmosphere by many ways,and becomes the odor pollution.At present,because of the effective economic and environmental friendly characteristics,bio filtration has become a research hotspot for treatment of malodorous gas field.But the bad controllability of the bed temperature and humidity hindered the industrial application of bio-filtration.Through this research,the temperature and humidity variations of biological bed have been researched.In this paper,the waste gas of the target pollutant was treated by biological filter.In the film coating,the removal rate of toluene gradually increased with the increase of toluene concentration gradient.The final toluene removal rate can reach 80%.The biofilm grew and the biomass of the bed increased.At the end of the film,the biomass of each layer of I tower was 1.1×109 CFU/g(the upper layer),5.9×109 CFU/g(the middle layer),and 3.6×109 CFU/g(the lower layer).The biomass of each layer of II tower was 1.9×108 CFU/g(the upper layer),1×108 CFU/g(the middle layer)and 1×108 CFU/g(the lower layer).With the biofilm growth,the pressure drop of the packed column increases gradually.At the end of the film,the maximum pressure drop of I tower is 44.1Pa,and the maximum pressure drop of II tower is 156.8Pa.Using peat as filler mixed wood,high biomass,low pressure drop,better than pure wood filler.In biological bed during normal operation,the wood chips of bio-bed layer is more stable,more biomass,treatment effect is better.The inlet gas of the water vapor can make the biological bed dry gradually.When the inlet humidity is 80%,the bed moisture content decreases 0.31% per day.With the bed water loss,the temperature of the biological bed gradually decreases.The biomass of the bed layer was decreased,the biomass of the fungus increased and the removal rate of toluene decreased gradually.The gas velocity of the bed was smaller,the biomass of the bed was decreased and the rate of the bed biomass decreased.Through irrigation can quickly replenish moisture of bed and rapidly effectively improve bed water rate of 10.4%,recovery bed removal effect,each irrigation can keep the bed layer effective operation for 10 days or more.