Organic carbon regeneration

New areas in adsorption technology include carbonaceous and polymeric resins (3). Based on synthetic organic polymer materials, these resins may find special uses where compound selectivity is important, low effluent concentrations are required, carbon regeneration is impractical, or the waste to be treated contains high levels of inorganic dissolved soHds. 

In recent years, supercritical fluid extraction has received widespread attention for the removal of non- or low-volatile organic components from liquid and solid matrices. This process has many potential applications like analytical extractions, applications in the food and drug industry, activated carbon regeneration or soil remediation. 

Varela, M. M., Barquero, S., Bode, A., Femadez, E., Gonzalez, N., Teira, E., and Varela, M. (2003a). Microplanktonic regeneration of ammonium and dissolved organic nitrogen in the upwelhng area of the NW of Spain Relationships with dissolved organic carbon production and phytoplankton size structure. J. Plankton Res. 25(7), 719—736. 

This section aims to give an overview of adsorption processes of metal ions by activated carbon. Three cases are detailed (1) the adsorption of metal ions onto virgin activated carbon adsorption capacities are given in static and dynamic reactors, and the influence of various operating conditions is shown (2) the adsorption of metal ions onto activated carbon preloaded with organic matter (3) the saturation of activated carbon by organic matter and metal hydroxides after its use in wastewater treatment. The influence of metal hydroxides on activated carbon regeneration is demonstrated. 

Activated carbon is a recommended and established process used in separating organic and certain inorganic species from aqueous waste streams. Normally, concentration of the waste species should be 1% or less so that carbon regeneration is less frequent. Since this process is generally cost-effective, it has been applied in numerous industrial municipal and pharmaceutical waste water treatment facilities. 

Activated carbon has limited application since not all sulfur compounds can be removed and the ill-smelling effluent can cause discomfort to people nearby. Air pollution caused due to the organic sulfur compounds, hydrocarbons, and CO contained in the regeneration gas can be controlled by incineration. However, emission of sulfur oxides must be controlled. Alternatively, the emissions from activated carbon regeneration can be eliminated more efficiently by substituting ZnO for the activated carbon desulfurization beds. The ZnO not only eliminates emissions, but saves energy and is a more effective desulfurization technique. 

Vertical distributions of dissolved Ba and total (dissolved+particulate) Pu, Am and Th in Framvaren Fjord all show increased concentrations with depth (Falkner etal., 1993 Roos etal., 1993). Ba cycling was dominated by its uptake into particulate matter associated with productivity in surface waters, followed by its regeneration at depth or in the sediments. Microbiological activity near the redox interface likely promotes the breakdown of settling particulate matter and the release of barite just above the 02/H2S interface (Falkner etal., 1993). Complex formation with dissolved organic carbon (DOC) is believed to be the main cause for the observed behavior of Pu, Am and Th (Roos etal., 1993). The distributions of these elements were not examined within the regions near the 02/H2S interface and the associated microbial layer. 

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