Study On Process Parameters Of SO₂ & NO Removal Simultaneously By A Rotating Drum Biofilter Coupled With Complexing Absorption By Fe^?EDTA

Nitrogen oxides?NOx?and sulfur dioxide?SO₂?are most important air pollutants,causing acid rain,being harmful to human health,resulting in the photochemistry smoke and climate change.The poroblem has caused the widespread attention,and the new technology for NOx and SO₂ control are particularly urgent.On the basis of the BioDeNOx investigation,the study combined complexing absorption with desulfurization and denitrification to remove NOx and SO₂ simultaneously in a Rotating drum Biofilter?RDB?,investigating the effects of process parameters on removal efficiency,as well as the production of H₂S.The results showed that the SO₂ reomoval effiency achieved above 90%and the NO reomoval effiency raised from 47%to 84%?stabilized between90.3%⁹2.6%finally?after the sludge domestication and early stages of biofilm formation and with the addition of 10 mM Fe^?EDTA.And,during 24day continuously operation,the good removal efficiency of NO and SO₂proved that feasibility of the investigation.When the SO₂ inlet concentration was around 2000 mg/m³ and NO inlet concentration was around 800 mg/m³,the effects of process parameter on removal efficiency showed that the maximal removal efficiency of SO₂achieved at 98.5%,while the miximal removal efficiency of NO achieved at93%under the optimum conditions of nutrient solution back flow rate 100ml/min,ERBT 1.8 min,pH 8.2,oxygen 2%.When the SO₂ inlet concentration kept at 2130 mg/m³,the production of H₂S achieved at670 mg/m³.The results showed that the H₂S production increased with the increase of SO₂ concentration and decreased with the increase of NO concentration,and was affected by pH and O₂ greatly.When pH was 4.1,because the activity of sulfate reductase was inhibited in low pH,the concentration of H₂S was under 20 mg/m³.And as sulfate reducting bacteria is strictly anaerobic,when O₂ concentration rised up to 8%,the H₂S concentration stayed below 45 mg/m³.High-throuhput screening results showed that the dominant denitrification bacteria?NR?was Pseudomonas which mainly distributed in outer sphere of RDB with a maximal abundance of 35.7%.The dominant sulfate reducting bacteria?SRB?was Desulfovibrio,which mainly distributed in nutrient solution with a maximal abundance of 35.7%at the period of high shock load of SO₂...