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Inlet Concentration (inlet + concentration)
Selected AbstractsExperimental and neural model analysis of styrene removal from polluted air in a biofilterJOURNAL OF CHEMICAL TECHNOLOGY & BIOTECHNOLOGY, Issue 7 2009Eldon R. Rene Abstract BACKGROUND: Biofilters are efficient systems for treating malodorous emissions. The mechanism involved during pollutant transfer and subsequent biotransformation within a biofilm is a complex process. The use of artificial neural networks to model the performance of biofilters using easily measurable state variables appears to be an effective alternative to conventional phenomenological modelling. RESULTS: An artificial neural network model was used to predict the extent of styrene removal in a perlite-biofilter inoculated with a mixed microbial culture. After a 43 day biofilter acclimation period, styrene removal experiments were carried out by subjecting the bioreactor to different flow rates (0.15,0.9 m3 h,1) and concentrations (0.5,17.2 g m,3), that correspond to inlet loading rates up to 1390 g m,3 h,1. During the different phases of continuous biofilter operation, greater than 92% styrene removal was achievable for loading rates up to 250 g m,3 h,1. A back propagation neural network algorithm was applied to model and predict the removal efficiency (%) of this process using inlet concentration (g m,3) and unit flow (h,1) as input variables. The data points were divided into training (115 × 3) and testing set (42 × 3). The most reliable condition for the network was selected by a trial and error approach and by estimating the determination coefficient (R2) value (0.98) achieved during prediction of the testing set. CONCLUSION: The results showed that a simple neural network based model with a topology of 2,4,1 was able to efficiently predict the styrene removal performance in the biofilter. Through sensitivity analysis, the most influential input parameter affecting styrene removal was ascertained to be the flow rate. Copyright © 2009 Society of Chemical Industry [source] Removal of TEX vapours from air in a peat biofilter: influence of inlet concentration and inlet loadJOURNAL OF CHEMICAL TECHNOLOGY & BIOTECHNOLOGY, Issue 3 2006Carmen Gabaldón Abstract This paper presents the results of the study of the removal of toluene, ethylbenzene, and o -xylene (TEX) by biofiltration using a commercial peat as filter-bed material. Runs with a single organic compound in air, and with the mixture of TEX in air, were carried out for at least 55 days in laboratory-scale reactors inoculated with a conditioned culture. The influence of organic compound inlet load and of gas flow rate on the biofilter's performance was studied, including relatively high values of pollutant inlet concentration (up to 4.3 gC m,3 for ethylbenzene, 3.2 gC m,3 for toluene, and 2.7 gC m,3 for o -xylene). Results obtained show maximum elimination capacities of 65 gC m,3 h,1 for o-xylene, 90 gC m,3 h,1 for toluene, and 100 gC m,3 h,1 for ethylbenzene, and high removal efficiency (>90%) even for moderately elevated concentrations: 3.0, 2.5 and 1.8 gC m,3 for ethylbenzene, toluene and o -xylene, respectively. The behaviour of the TEX mixture was in good agreement with the results obtained for the runs in which only one organic compound was present. Ethylbenzene and toluene are degraded easier than o -xylene, and inhibitory effects due to the presence of multiple substrates were not observed. Copyright © 2005 Society of Chemical Industry [source] The removal of iron and cobalt from aqueous solutions by ion exchange with Na-Y zeolite: batch, semi-batch and continuous operationJOURNAL OF CHEMICAL TECHNOLOGY & BIOTECHNOLOGY, Issue 6 2002Jong Sung Kim Abstract The removal of single component and binary mixtures of divalent cobalt and iron from water by ion exchange with synthetic Y zeolite has been studied in batch, semi-batch and continuous modes of operation; the initial metal solution concentration did not exceed 2,mmol,dm,3. Binary Co/Na and Fe/Na ion exchange equilibrium isotherms (294,K) are presented wherein exchange site heterogeneity is evident in the case of the iron treatment. Under conditions of stoichiometric ion exchange, removal efficiencies for both cobalt and iron decrease with increasing metal concentration (0.2,2,mmol,dm,3) and the values were similar for both metals. Removal of cobalt under transient conditions was found to be temperature dependent. In the fixed bed operation, break-through behavior was sensitive to changes in both flow rate and inlet concentration. The break-through profiles for both metals under competitive and non-competitive conditions are presented; iron removal is lower in the presence of cobalt and vice versa. An in situ regeneration of the fully loaded zeolite by back exchange with sodium is considered and the exchange capacity of the regenerated zeolite is reported. The feasibility of employing cycles of heavy metal uptake/zeolite regeneration is addressed. © 2002 Society of Chemical Industry [source] Catalytic Combustion of Ethyl Acetate over Nanostructure Cobalt Supported ZSM-5 Zeolite CatalystsCHINESE JOURNAL OF CHEMISTRY, Issue 3 2009Aligholi NIAEI Abstract Gas phase catalytic combustion of ethyl acetate, as one of volatile organic compounds (VOC), was studied on nanostructure ZSM-5, HZSM-5 and Co-ZSM-5 with different cobalt loadings. Nanostructure of ZSM-5 was determined by XRD, SEM and TEM. Catalytic studies were carried out under atmospheric pressure in a fixed bed reactor. Results showed that the Co-ZSM-5 catalysts had better activity than others and at temperatures below 350 °C, amount of Co loading was more effective on catalytic activity. The order of conversion of ethyl acetate over different Co loading is as follows: Co-ZSM-5 (0.75 wt%)
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