Separation processes biological separations

Chemical Processes. Biological—biochemical and thermal conversion processes are chemical processes, too, but a few specific chemical processes are mentioned separately because they are directed more to conventional chemical processing and production. These processes have been grouped together as chemical processes. 

Biological processes are also being studied to investigate abiHty to remove sulfur species in order to remove potential contributors to acid rain (see Air pollution). These species include benzothiophene-type materials, which are the most difficult to remove chemically, as weU as pyritic material. The pyrite may be treated to enhance the abiHty of flotation processes to separate the mineral from the combustible parts of the coal. Genetic engineering (qv) techniques are being appHed to develop more effective species. 

Irreversible processes are mainly appHed for the separation of heavy stable isotopes, where the separation factors of the more reversible methods, eg, distillation, absorption, or chemical exchange, are so low that the diffusion separation methods become economically more attractive. Although appHcation of these processes is presented in terms of isotope separation, the results are equally vaUd for the description of separation processes for any ideal mixture of very similar constituents such as close-cut petroleum fractions, members of a homologous series of organic compounds, isomeric chemical compounds, or biological materials. 

T. Alan Hatton, Ph.D., Ralph Landau Professor and Director of the David H. Koch School of Chemical Engineering Practice, Massachusetts Institute of Technology Founding Fellow, American Institute of Medical and Biological Engineering Member, American Institute of Chemical Engineers, American Chemical Society, International Association of Colloid and Interface Scientists, American Association for the Advancement of Science, Neutron Scattering Society of America (Section 22, Alternative Separation Processes)... 

Sludge Precipitated mechanically or biologically separated solid matter produced during water and or sewage treatment or industrial processes. Such solids may be amenable to biological control. 

Centrifugation is a well-established liquid-solid separation process popular in commercial and municipal waste treatment facilities. It is usually used to reduce slurry and sludge volumes and to increase the solids concentration in these waste streams. It is a technically and economically competitive process and is commonly used on waste sludges produced from water pollution control systems and on biological sludges produced in industry and municipal treatment facilities. 

Many technologies have been proposed for detoxifying waste by processes that destroy chemical bonds pyrolytic biological and catalyzed and imcatalyzed reactions with oxygen, hydrogen, and ozone. The following sections deal only with research opportunities in the areas of thermal destmction, biodegradation, separation processes, and wet oxidation. 

An understanding of these LR dynamics requires both biological and mathematical insight. In this chapter we define these biological processes in terms of RG mechanisms and consider whether these processes reflect receptor in different states of activity. Next we develop a mathematical description to account for at least six separate processes (1) ligand association, (2) rapid ligand dissociation, (3) slower dissociation, (4) internalization, and (5 and 6) two different Interconversions among receptor forms. 

Applications Membranes create a boundary between different bulk gas or hquid mixtures. Different solutes and solvents flow through membranes at different rates. This enables the use of membranes in separation processes. Membrane processes can be operated at moderate temperatures for sensitive components (e.g., food, pharmaceuticals). Membrane processes also tend to have low relative capital and energy costs. Their modular format permits rehable scale-up and operation. This unit operation has seen widespread commercial adoption since the 1960s for component enrichment, depletion, or equilibration. Estimates of annual membrane module sales in 2005 are shown in Table 20-16. Applications of membranes for diagnostic and bench-scale use are not included. Natural biological systems widely employ membranes to isolate cells, organs, and nuclei. 

Process economics for biological products was discussed by Harrison et al. (op. cit., pp. 334—369) and Datar and Rosen [in Asenjo (ed.). Separation Processes in Biotechnology, DeUcer, New York, 1990, pp. 741-793] at length, and also by Ladisch (op. cit., pp. 401—430). They provided some illustrative examples with cost an yses. Bioprocess design software can also prove helpful in the overall design process (Harrison et al., op. cit., pp. 343-369). 

Ionization is the process of separation or dissociation of a molecule into particles of opposite electrical charge (ions). The presence and extent of ionization has a large effect on the chemical behavior of a substance. An acid or base that is extensively ionized may have markedly different solubility, sorption, toxicity, and biological characteristics than the corresponding neutral compound. Inorganic and organic acids, bases, and salts may be ionized under environmental conditions. A weak acid HA will ionize to some extent in water according to the reaction ... 

The preceding accomplishments are applied in nature, but required tremendous amounts of basic research on mass transfer, interactions of materials with biological components, fluid dynamics, separation processes (especially chromatography and membrane separations), and biochemical kinetics. 

UOP FCC unit, 11 700-702 UOP/HYDRO MTO process, 18 568 UOP Olex olefin separation process, 17 724 Up-and-Down Method, 25 217 U/Pb decay schemes, 25 393-394 Updraft sintering, 26 565 Upflow anaerobic sludge blanket (UASB) in biological waste treatment, 25 902 Upgraded slag (UGS), 25 12, 33 Upland Cotton, U.S., 8 13 U-Polymer, 20 189 Upper critical solution temperature (UCST), 20 320, 322 Upper explosive limit (UEL), 22 840 Upper flammability limit, 23 115 Upper flammable limit (UFL), 22 840 Upper Freeport (MVB) coal... 

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