| In recent years,as China’s environmental management efforts continue to increase,a large number of sewage treatment plants have been constructed and put into use,but in the process,some harmful gases are often generated,polluting the surrounding ambient air.In order to improve the environmental sanitation level of the plant area and surrounding areas,the odor needs to be treated,but the existing methods often require an independent deodorization unit,which is expensive and difficult to operate and manage.This paper aims at a typical urban sewage treatment plant of AAO process in Chongqing,applying a collaborative deodorization system that connects the deodorization ventilation system of the process space with the biochemical blast aeration system.The technical scheme is to use odor instead of air for aeration,and at the same time use activated sludge in the aeration tank to remove odor.The application of this program does not require the installation of independent deodorization facilities,which can reduce the initial investment of the sewage plant and save land resources and operating costs.Since the aeration air volume is smaller than the original deodorization design air volume and will change with the sewage treatment situation,the deodorization air volume needs to be reduced to match the aeration air volume to ensure the normal operation of the sewage treatment process.The task of this study is to design a set of deodorizing pipe network system suitable for this scheme,and to optimize the transformation of the gas gathering devices at the end of the original process structure to adapt it to the new deodorizing system.This article first introduces the engineering overview of the sewage plant,on this basis leads to the unreasonable design of the deodorization system including the lifting pump room and the coarse grid,the sludge dewatering machine room,the primary sedimentation tank,and the corresponding A feasible modification plan for the new collaborative deodorization pipe network system.For the area between the lifting pump room and the coarse grid,the new isolation scheme is in good condition after being put into use.Aiming at the initial settling tank,a new capping scheme was proposed to remove the anti-hanging membrane and greatly reduce the volume of the deodorizing space.The application of this new scheme not only greatly reduces the deodorizing air volume,but also adapts to the requirements of aeration air volume.Aiming at the sludge dewatering machine room,based on literature research and on-site testing and analysis,this paper proposes an air curtain to block odors.This plan uses fans to generate air curtains to achieve the purpose of blocking odors without affecting workers’operations.In order to verify the isolation effect of the air curtain against odor,this article based on actual engineering,reduced the geometric size according to the principle of similar model,and used CO2 as the tracer gas to build an odor emission model corresponding to the actual engineering system,and obtained Control the minimum isolation wind speed at which odor does not escape,and the odor removal efficiency under different air volume conditions.Use ICEM to draw a grid,establish a simplified odor ventilation model,and adjust the position of the odor air intake,and use the computational fluid dynamics（CFD）method to perform simulation calculations to determine the degree of influence of the location of the suction air intake on the airflow organization.In order to facilitate the construction and operation management,it is proposed to replace the integrated air curtain in the experiment with a finished air curtain fan,and use a transparent magnetic suction curtain to isolate the odor outside the operator’s operating surface.After the above three odor-generating terminals are transformed,the deodorizing air volume is greatly reduced,and the purpose of the transformation matching the aeration air volume is achieved.Taking this project as an example,the capped collection method and odor treatment process described in this article can reduce the total investment of the capped deodorization project by about 5 million yuan,and reduce the operating cost by about500,000 yuan every year.In order to analyze the technical feasibility of the odorous collaborative aeration and deodorization pipeline network,the pipeline network system was transformed and designed.Through the pipeline network self-balance calculation,the pipeline network was within the reasonable fluctuation range of the aeration air volume,and all branches met Stinky design minimum air volume requirements.Comparing the concentration of the cooperative aeration intake with the concentration of the diffuser in the aeration tank,the removal of pollutants is good,and there is no obvious effect on the water quality of the aeration tank before and after the transformation.The above conclusions indicate that the odorous gas synergistic aeration and deodorization technical solution is worthy of promotion and reference for other sewage treatment plants. |
