Kinetics studies on the removal of Methyl ethyl ketone using cornstack based biofilter

The performance of cornstack based biofilter inoculated with a mixed culture was evaluated for gas phase MEK removal under various operating conditions. Experiments were carried out at different flow rates (0.03-0.12m³h^-1) and various initial concentrations (0.2-1.2g^-3). A maximum elimination capacity (EC) of 35g^-3h^-1 was achieved at an inlet loading rate of 60g^-3h^-1 with a removal efficiency of 95%. High elimination capacity reached with this system could have been due to the dominant presence of filamentous fungi among others. The experimental results were compared with the values obtained from the Ottengraf-van den Oever model for zero-order diffusion-controlled region. The critical inlet concentration, critical inlet load and biofilm thickness were estimated using the model predictions.

Treatment of xylene polluted air using press mud-based biofilter

In the present work, biofiltration of xylene vapors has been investigated on a laboratory scale biofilter packed with press mud as filter material inoculated with activated sludge from pharmaceutical industry. Four various gas flow rates, i.e. 0.03, 0.06, 0.09 and 0.12 m(3) h(-1), were tested for inlet xylene concentration ranging from 0.2 to 1.2 g m(-3). The biofilter proved to be highly efficient in the removal of xylene at a gas flow rate of 0.2m(3) h(-1) corresponding to a gas residence time of 2.8 min. For all the tested inlet concentrations, the removal efficiency decreased for high gas flow rates. For all the tested gas flow rates, a decrease in the removal efficiency was noticed for high xylene inlet concentration. The follow-up of carbon dioxide concentration profile through the biofilter revealed that the mass ratio of carbon dioxide produced to the xylene removed was approximately 2.52, which confirms complete degradation of xylene if one considers the fraction of the consumed organic carbon used for the microbial growth.

Elimination of volatile organic compounds by biofiltration: a review

Volatile organic compounds (VOCs) are pollutants that are responsible for the formation of the tropospheric ozone, one of the precursors of smog. VOCs are emitted by various industries including chemical plants, pulp and paper mills, pharmaceuticals, cosmetics, electronics and agri-food industries. Some VOCs cause odor pollution while many of them are harmful to environment and human or animal health. For the removal of VOCs, biofiltration, a biological process, has proved to be reliable when properly operated. This process has therefore been widely applied in Europe and North America. The main advantages associated with the use of biofiltration are related to its set-up, maintenance, and operating costs which are usually lower than those related to other VOCs control technologies and because it is less harmful for the environment than conventional processes like incineration. In the present paper, the main parameters (type, moisture, pH, and temperature of filter bed, microbial population, nutrients concentrations, and VOCs' inlet load) to be controlled during the biofiltration are identified and described in detail. The main phenomena involved in biofiltration are also discussed. For improving the efficiency of VOC control biotechnology, new techniques are now proposed that include the use of membranes, biphasic reactors, UV photolysis, and many others.