Study On Biotrickling Filter With Foam Ceramics

Along with the development of the industry and the improvement of people’s livingstandard, volatile organic compounds(VOCs) emissions increases gradually. As animportant kind of air pollution，the VOCs not only do great harm to natural environmentand people’s health，also more and more attention has been focused on the managementand treatment. In particularly, biofiltration is known as an efficient, economical andenvironmental friendly technology, and having no second pollutions. It has been appliedmore broadly in industrial waste gases treatment. How to better use its effect andimprove its efficiency is the hotspot research.Filler is attached to the microbial growth and material transfer of the carrier. It is thecore of biological reaction device and directly influence the contamination removal ineffect. Foam ceramic is a new kind of inorganic non-metallic filter material. It has thethree-dimensional network skeleton and high porosity rate. Compared with the traditionalfilter material, foam ceramic quality light, high strength, high temperature corrosionresistance, low cost and filter the effect is good.This paper studies the foam ceramic packing used for biotrickling filter removetoluene gas.Two kinds of packing materials, foam ceramics and ceramic pellets, wereloaded into two identical biotrickling filters respectively to compare the microbialremoval efficiency of waste gas containing toluene by seeding with same bacteria.Theaffecting parameters of the removal performance, such as gas flow rates, inlet tolueneconcentrations were investigated in detail in biotrickling filters. Compared with the twoidentical biotrickling filters, the biological filter facking used foam ceramic are betterthan the ceramic pellets packed tower. Foam ceramic is suitable for the filler ofbiotrickling filter.With the same influent toluene concentration, the removal efficiencies follow withthe imported gas velocity change. When the gas flow rates respectively at150L/h,300L/h,600L/h, the foam ceramics average removal efficiency of toluene maintained99.4%,93%,55.1%. The removal efficiency are higher than the ceramic pellets packedtower.When varying the inlet toluene concentrations, ranged from100mg/m~3to1100mg/m~3,the REs are able to maintain nearly95.5%at the inlet concentration of400mg/m~3orbelow. With the inlet toluene concentrations increased to800mg/m~3, the average RE is 78.7%. When the inlet toluene concentrations increased to1100mg/m~3, the average RE isstability at41.2%. Biological tower with the ability to remove filter import organic loadincreases gradually rise. When reach the highest load75.1g/m~3·h, trend gentle no longerchange.The height of Packing filler also effects the removal efficiency of biological filter. Inthe low gas velocity conditions, removal efficiency increase with the height of the packingfiller. Based on its higher removal capacity of toluene and shorter recovery time, foamceramics would be a better choice than ceramic pellets for packing material used forbiotrickling filter.