Numerical Simulation Of Landfill Odor Diffusion Law And Its Impact On Downstream Buildings

With the rapid increase of all kinds of rubbish produced by city,the influence of odor coming from the landfill surrounding the cities for urban construction planning has become increasingly apparent.Therefore,the research of the landfill odor diffusion regularity and its influence on the downstream buildings has important practical significance and application value.According to domestic and international research about pollutants diffusion,the dispersion law of landfill odor and its influence on the downstream buildings by FLUENT is simulated.Firstly,adopting the different k-? turbulence models,turbulent Schmidt number and boundary conditions of pollutants entrance to simulate the wind tunnel experiment by university of Florence.Comparing the results of numerical simulation with wind tunnel experiment results to verify the feasibility of the study of landfill gas diffusion by FLUENT.Based on the numerical simulation method,this paper researched the typical diffusion phenomenon of the odor of laohukeng landfill in Shenzhen,also analyzed the influence of different pollutant inlet boundary on the numerical simulation results and the dispersion law of landfill odor.In addition,the influence of downstream buildings layout of the landfill on concentration distribution of odor around the buildings is researched.The research results show that,compared with the velocity inlet boundary conditions,the boundary conditions of pollutants entrance set as wall boundary and in close to the boundary layer of the grid defined contaminated items makes the results of numerical simulation more appropriate.Considered the effect of different size of wind speed on the odor concentration,results showed that wind flow wind speed does not affect the diffusion regularity of odor,but the multiples of odor concentration decreases ratio similar with the increase of wind speed.Refer to Japanese law on the prevention and control of the odor,the ammonia released by laohukeng landfill caused minimal impact to human body under the condition of the annual average wind speed of Shenzhen.But the hydrogen sulfide concentration is so high thatthe citizens located in the downwind of the landfill should stay more than 1100 m away from the landfill site to make it difficult to feel the smell.The results of simulated the effect of landfill downstream buildings layout on landfill odor diffusion show that,when villa decorate before the high-rise building,the dilution effect of near-surface odor around the buildings is the worst.In high-rise buildings is staggered type layout situation,when villa located in the downwind of high-rise buildings,adopt the front row of high-rise buildings and villa as the determinant layout and the back row of high-rise buildings and villa is staggered type layout,made near-surface odor dilution effect better.Similarly,when villa arrangement between the high-rise buildings,adopt the back row of high-rise buildings and villa as the determinant layout and the front row of high-rise buildings and villa is staggered type layout,also made near-surface odor dilution effect better.The results of this research can provide reference for the numerical simulation of the dispersion of landfill odor,also can provide theoretical foundation for the site selection of landfill and the building group layout adjacent to the landfill.