in this paper, the present state of knowledge about axial mixing in gasliquid reactors is reviewed. a brief outline of the methods for measuring residence time distribution(rtd)of various phases in a multiphase reactor is presented. this is followed by a short description of differential and stage-wise models for characterizing back mixing from rtd measurments. backmixing characteristics of som...

This study was aimed at introducing a novel bioflocculant to enhance anaerobic granulation in a UASB reactor for lowstrength synthetic wastewater and comparing the effect with synthetic polymers. A laboratory-scale study was undertaken to achieve this goal. Four identical UASB reactors were operated in parallel in the treatment of low-strength synthetic wastewater over 136d at 35 ± 1 °C. One un...

Six advanced reactor concepts have been selected for Generation-IV reactors and are being investigated worldwide to meet the challenging goals of effective resource utilization and waste minimization (sustainability), improved safety, enhanced proliferation resistance, and reduced system cost. [1] The six systems are very high temperature reactor (VHTR), sodium-cooled fast reactor (SFR), superc...

Biochemical processes by chemoautotrophs such as nitrifiers and sulfide and iron oxidizers are used extensively in wastewater treatment. The research described in this dissertation involved the study of two selected biological processes utilized in wastewater treatment mediated by chemoautotrophic bacteria: nitrification (biological removal of ammonia and nitrogen) and hydrogen sulfide (H2S) re...

We developed a dynamic flux balance model for fed-batch Saccharomyces cerevisiae fermentation that couples a detailed steady-state description of primary carbon metabolism with dynamic mass balances on key extracellular species. Model-based dynamic optimization is performed to determine fed-batch operating policies that maximize ethanol productivity and/or ethanol yield on glucose. The initial ...

the down-flow hanging sponge (dhs) reactor, which was developed for post-treatment of effluent from up-flow anaerobic sludge blanket (uasb) process treating sewage, uses polyurethane sponge as media to retain biomass. wastewater is trickled from the top of the reactor and purified by microorganisms retained both inside and outside of the sponge media as the wastewater flows vertically down thr...

anaerobic digestion of organic solid waste (osw) from kitchen was conducted in completely stirred tank reactors (cstrs) under both mesophilic and thermophilic conditions. the lab-scale reactors were fed with the osw containing 10% of total solids (ts) at a hydraulic retention time (hrt) of 30 days (3.0-3.5 g-ts/l/d of volumetric loading rate). both mesophilic and thermophilic reactors exhibited...

India's nuclear power program is based on indigenous materials and technology, with the potential for providing energy security for many centuries. This paper examines the technical validity of this plan, specifically the role of breeder reactors for extending the domestic uranium supplies. Our study shows breeding is unlikely to occur at anywhere near the rates envisioned, leading to a slow gr...

The current regulations for nuclear power plants focus on light water reactors (LWRs), and as such they may not be properly applied to non-LWR reactors such as Generation IV Reactors. For instance, there is no plant state comparable to core damage in pebble bed reactors [1]. As a result, the surrogate safety goal based on core-damage frequency (CDF), as being applied to LWRs in many countries d...

We report a study of the continuous generation of polymer particles in parallel multiple modular microfluidic (M3) reactors. Each module consisted of sixteen parallel microfluidic reactors comprising emulsification and polymerization compartments. We identified and minimized the effects of the following factors that could result in the broadening of the distribution of sizes of the particles sy...