生物滴滤塔脱除污泥干化尾气中的SO_(2)

Removal of sulfur dioxide from exhaust gas of sludge drying by biotrickling filter tower

以市政污泥干化尾气中的主要含硫物质二氧化硫 (SO_(2)) 为处理对象,从市政污泥中筛选出高效脱硫菌——嗜酸性氧化亚铁硫杆菌 (Acidithiobacillus ferrooxidans,A.f),搭建了实验室规模的生物滴滤塔,考察了进气质量浓度、气体停留时间、营养液喷淋密度和营养液中 Fe^(2+)浓度对生物滴滤塔脱除 SO_(2)的影响。结果表明:在SO_(2)质量浓度约合 38~304 mg·m^(-3)(即常温常压下 100~800 ppm) 时,脱硫效率稳定在约 97%;当气体停留时间由150 s 降至 30 s 时,脱硫效率迅速降至 75%;当营养液的喷淋密度小于 0.36 m^(3)·(m^(2)·h)^(-1)时,脱硫效率降至 92%,但喷淋密度为 0.36~1.08 m^(3)·(m^(2)·h)^(-1)时,脱硫效率保持在约 97%;当作为生物脱硫反应关键的液相 Fe^(2+)浓度由0.1 mol·L^(-1)降至 0.02 mol·L^(-1)时,脱硫效率迅速降至 84% 以下。本研究结果可为生物脱硫技术的推广应用提供参考。

Sulfur dioxide (SO_(2)), which is the main sulfur-containing substance in the exhaust gas of sludge drying process, was chosen as the subject in this paper. A laboratory-scale biotrickling filter tower was constructed by screening the highly efficient desulfurization bacteria Acidithiobacillus ferrooxidans (A.f) from municipal sludge. The effects of inlet gas mass concentration, gas residence time, nutrient solution spray density and Fe^(2+)concentration in nutrient solution on the removal of SO_(2)in the biological trickling filter tower were investigated. Results showed that when the concentration of SO_(2)changed from 38 to 304 mg·m^(-3)(around 100 to800 ppm under room temperature and pressure), the desulfurization efficiency basically maintained at abou97%, but the desulfurization efficiency dropped rapidly to 75% when the gas residence time decreased from150 s to 30 s. The desulfurization efficiency rapidly decreased to 92% when nutrient solution spray density was less than 0.36 m^(3)·(m^(2)·h)^(-1), while when the spraying density was in the range of 0.36-1.08 m^(3)·(m^(2)·h)^(-1), the desulfurization efficiency remained close to 97%.. When the concentration of Fe^(2+)decreaced from 0.1 mol·L^(-1) to 0.02 mol·L^(-1), the desulfurization efficiency rapidly decreased to below 84%. This results of the can provide reference for the promotion and application of biodesulfurization technology.