The Basic Application Research Of Adding Sodium Sulfite To Purify Formaldehyde Waste Gas In Biofilm Packing Tower

Formaldehyde is a colorless,a strong pungent odor,it is easy to dissolve in the water of the organic waste gas pollutants.It can not only to cause serious environment pollution,but also can bring great harm to people health.It is widely used and produced,it plays an important role in the people’s daily life.Biological method purify formaldehyde gas technology because of its economic efficient and pollutant treatment thoroughly,no secondary pollution and so on characteristics,It develops into a hot spot and research area of purifying industrial waste gas gradually in the world.The research object in this paper,Because of formaldehyde could easily soluble in water,related research reports of high purification efficiency,its essence is the result of formaldehyde from gas phase to the liquid phase,not the actual meaning of purification degradation.Formaldehyde liquid biochemical degradation reaction,therefore,need to strengthen measures,improve the reaction rate,biochemical purification effect to enhance formaldehyde emission.Selecting the biological tricking filter spray liquid,using single factor experiment and orthogonal experiment,the biological purifying technology and kinetic model of formaldehyde waste gas is researched by using biological tricking filter.The main results were summarized as follows:（1）Spray liquid selective experiment results show that,the pH 8 sodium sulfite solution for spray liquid of Biological tricking filter,the purification product for environmentally such as CO₂,H₂O.And do not produce SO₂,liquid product（CH₂（OH）SO₃Na）was not only beneficial to the growth of microorganism and also could promote the Biological tricking filter gas purification effects.And the purification efficiency was higher than the water and other spray liquids.（2）Biological tricking filter the optimum operating conditions to explore the experimental results show that the optimum operating conditions for:spray liquid flow 5 L/h,gas flow rate is 0.4 m³/h,gas phase formaldehyde import concentration80 mg/m³,the biological tricking filter purification formaldehyde gas has the best performance.The maximum number of formaldehyde removal is much higher than the similar research of 6.86 mg/（L·h）and 10.42 mg/（L·h）,that the Na₂SO₃ spray liquid packed tower formaldehyde purification achieved good effects.（3）The result of Biological tricking filter purification formaldehyde bio-chemical kinetics reaction research show that,Biochemical degradation reaction of formaldehyde in biological is first-order reaction,first-order surface reaction velocity parameter K₁=0.0243 s^-1.Compared with the same kind of research first order reaction rate constant had increased 3.5 times.The biochemical reaction of formaldehyde is slow-rate.The absorption rate is controlled by slow-rate biochemical reaction.That the Na₂SO₃ spray liquid has increased the purification rate of formaldehyde.（4）The kinetic models were established based on "Absorption-Biological" and "Adsorption-Biological" theory,the results showed that the interrelation coefficient between calculated data and experimental data of the effluent gas、the purification efficiency、the biological elimination of formaldehyde has good relationship.The forward’s correlativity between calculated data and experimental data is better.The "Absorption-Biological" theory could describe the reaction better than the "Adsorption-Biological" theory.