The discharge of cyanide-containing effluents into the environment contaminates water bodies and soil. Effective methods of treatment which can detoxify cyanide are the need of the hour. The aim of the present study is to develop a bioreactor for complete degradation of cyanide using immobilized cells of Serratia marcescens RL2b. Alginate-entrapped cells of S. marcescens RL2b were used for comp...

Abstract--The selective oxidation of ethene over a silver on cx-alumina catalyst was studied in a pilot plant with a wall-cooled tubular packed bed reactor. Gas and solid temperatures in the catalyst bed were measured at different axial and radial positions as well as concentrations at different axial position. Total pressure, inlet mole fraction ethene, mass flow rate and wall temperature were...

Immobilized cells of a recombinant Escherichia coli expressing nitrilase from Pseudomonas putida were used to catalyze the hydrolysis of mandelonitrile (2hydroxy-2-phenylacetonitrile) to (R)-(-)-mandelic acid. The cells had been immobilized by entrapment in an alginate matrix. Conditions for the hydrolysis reaction were optimized in shake flasks and in a packed bed reactor. In shake flasks the ...

The mechanism of the formation for cocurrent downflow pulse flow was studied experimentally in a packed-bed of inert spheres of 3, 6, and 8 mm using an air-water flow. By measuring the flow distance until pulses are observed, the spatial growth rate of convective disturbances within the pulsing-flow regime were determined. Observations indicate that pulses form from trickling-flow as the result...

This study investigated perchlorate reduction by sulfur utilizing perchlorate reducing bacteria (SUPeRB). SUPeRB cultures were enriched from a denitrifying wastewater inoculum in medium containing elemental sulfur (S), crushed oyster shell, nutrients and perchlorate. Perchlorate was reduced from 5 to < 0.5 mg/L in approximately 15 days. The enrichment culture was subsequently inoculated into a ...

Most of the slaughterhouses in the state of Kerala (India) do not have proper and effective effluent treatment facilities. Collection of blood and separation of manure to reduce the very high organic load of the effluent are also not practiced. As a result, large volumes of extremely complex effluents with high content of fat, grease, and protein are discharged into land or water bodies causing...

Chemical engineering operations commonly involve the use of packed and fluidized beds. These are devices in which a large surface area for contact between a liquid and a gas (absorption, distillation) or a solid and a gas or liquid (adsorption, catalysis) is obtained for achieving rapid mass and heat transfer, and particularly in the case of fluidized beds, catalytic chemical reactions. You wil...

The biosorption of copper by inactivated biomass of the brown seaweed Sargassum baccularia, immobilized onto polyvinyl alcohol (PVA) gel beads, was investigated using a laboratory-scale packed bed column. Continuous-flow column tests were performed to determine breakthrough curves at two different column lengths. In both cases, a very broad trailing edge of the breakthrough curve was observed, ...

The mechanism of displacement washing of packed bed of porous, compressible and cylindrical particles, e.g., fibers, is presented with the help of an axial dispersion model involving Peclet number (Pe) and Biot number (Bi). Bulk fluid concentration, intra-pore solute concentration and concentration of solute adsorbed on the fiber surface are taken to be the function of washing time and position...

Catalysts and catalyst binders are significant portions of the cost of microbial fuel cell (MFC) cathodes. Many materials have been tested as aqueous cathodes, but air-cathodes are needed to avoid energy demands for water aeration. Packed-bed air-cathodes were constructed without expensive binders or diffusion layers using four inexpensive carbon-based materials. Cathodes made from activated ca...