Waste process streams, automated

Scientists at PNNL have developed an automated radiochemical sample preparation-separation-detection system for the determination of total "Tc in nuclear-waste process streams.46 85 86 144145 This analyzer was designed to support a technetium removal process planned as part of the development of a nuclear-waste processing plant. The process stream composition is both complex and variable, with a high pH, high salt matrix. Depending on the source of the feed, the total base content, the concentration of organics, and complexant concentrations will vary, as will the aluminum, nitrate, nitrite, dichromate, and radionuclide composition. 

Automated Analyzer for Radionuclides in Nuclear Waste Process Streams... 

Process monitoring poses two additional challenges compared to these automated fluidic separation methods. First, methodology for automated sample preparation must be developed, and second, the entire sample preparation-separation-detection system must be developed to operate on-line or at-site under unattended computer control, including sample transport through all the steps. Sample preparation is particularly critical for nuclear-waste and nuclear-process streams due to the complexity of the sample matrix and the uncontrolled valence states of several of the potential analytes. 

A process chromatograph is an enviromnentally suitable automated device that measures one or more chemical components in one or more process streams and presents the results in a usable format. A process chromatographic system includes the associated sample system, utilities, waste handling, and data communication as well as the instrument itself. 

After polymerization, PET is processed to final products, distributed to consumers and eventually ends up in a waste treatment system. Manual sorting or various automated methods can be applied to separate the PET fraction from a waste stream [HI]. 

Figure 3.22 Two realizations of cross-stream cutter solutions to process sampling involving significantly heterogeneous aggregate materials (broken ore, raw material, powders, intermediates, cement, waste, soil, other). The gravity-driven, rotating cross cutter [left] does not comply with TOS requirements (highly detrimental IDE and lEE), while the automated cross-stream cutter implemented at the terminal end of a conveyor belt [right] can be easily optimized to eliminate all ISEs. See [3,14] for a broad discussion of all issues related to process industry cross-stream sampler principles, and [11,21] for particular details.

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