Removal of triethylamine vapor from waste gases by biotrickling filter

Sampling of triethylamine in the cold-box unit in an auto-manufacturing company in Iran has indicated the average concentration of 430 mg/m[3] in the emission duct. In this study a biotrickling filter was used for treatment of triethylamine in air stream. Triethylamine removal efficiency [K/L] pattern was evaluated by changing volumetric loading [L], superficial gas velocity [U[o]], empty bed gas retention time [EBRT] and recirculation liquid flow rate [V[L]], while operating at constant temperature of 25 +/- 1 Degree C. For finding the effect of EBRT on the triethylamine removal efficiency, tests were performed at EBRT of 156 s, 52s and 31s and a constant liquid recirculation velocity of 3.466 m[3]/m[2]/h. Results showded that for a test period of 65 days, triethylamine removal efficiencies of more than 98% were obtained for EBRT of 156s and loading rates of less than 48 g/m[3]/h. With an EBRT of 52s removal efficiencies of > 90% were obtained for loadings of < 57 g/m[3]/h and maximum removal capacity was 53.4 g/m[3]/h at volumetric loading of 64 g/m[3]/h. Also with an EBRT of 31 s the maximum removal capacity was 53.6 g/m[3]/h at volumetric loading of 68 g/m[3]/h. Thus in the range of implemented EBRTs the proper absorption of triethylamine from gas to liquid phase took place and the elimination efficiency was shown to be dependent on microorganisms activity rate. The effect of liquid flow rate on the triethylamine removal efficiency was investigated by changing VL in the range of 3.46 to 10.40 m[3]/m[2]/h at EBRT=31 s and influent triethylamine concentration of 600 mg/m[3]. Results showed that the triethylamine removal efficiency was nearly independent of the liquid recirculation rate

Particulate polycyclic aromatic hydrocarbons in Urban Air of Tehran

Polycyclic Aromatic Hydrocarbons are ubiquitous in the urban atmosphere and one of the most atmospheric pollutants to be identified as suspected carcinogens .The objective of this study was to compare particulate PAH profiles from several sites across Tehran. Atmospheric concentrations of Polycyclic Aromatic Hydrocarbons in Tehran were evaluated to study particulate PAH profiles in different sites. The particles size distributions were unimodal with a fine mode diameter [PM<0.49 micro m]. Five sites were selected in residential areas and one site in rural area for representing various situations and role of motor vehicles in producing Polycyclic Aromatic Hydrocarbons. Organics on the filter were extracted with acetonitrile and a group of 16 Polycyclic Aromatic Hydrocarbons was selected for evaluation. PAH identification was done by High Performance Liquid Chromatography. Total PAH concentration associated with particles collected on the six-stage cascade impactor stages and after-filter in different sites ranged between 0.132 to 234.3 ng/m[3]. The mean concentrations of Polycyclic Aromatic Hydrocarbons, collected on each stage were: 4.17 ng/m[3] for PM[10-7.2] micro m, 5.69 ng/m[3] for PM[7.2-3] micro m, 11.95 ng/m[3] for PM[3-1.5] micro m, 9.18 ng/m[3] for PM[1.5-0.95] micro m, 2.82 ng/m[3] for PM[0.95-0.49] micro m and 47.91 ng/m[3] for PM < 0.49 micro m respectively