Waste extraction studies with

Extraction Studies with Zr-Al High-Level Waste... 

The electrolysis of a mixture of ZnCl2 with alkaline chlorides and the effect of different elements were investigated as a method to extract zinc from ores and industrial wastes. The studies on electrolysis of ZnCl2 in molten ZnCl2-KCl-NaCl... 

DHDECMP EXTRACTION-SCRUB-STRIP STUDIES WITH SYNTHETIC Zr-Al COPROCESS WASTE... 

There are many examples of the studies on SLM for nuclear applications in the literature. SLMs were tested for high-level radioactive waste treatment combined with removal of actinides and other fission products from the effluents from nuclear fuel reprocessing plants. The recovery of the species, such as uranium, plutonium, thorium, americium, cerium, europium, strontium, and cesium, was investigated in vari-ons extracting-stripping systems. Selective permeation... 

Firstly, the synthetic processes were assessed to investigate possible reduction in the use of raw materials, solvents and catalysts. Any wastes produced were then studied with respect to solvent recovery by distillation and reuse in the original process. Parts of the waste not reusable were assessed for separation and sale to third parties for recovery and reuse. Finally, any non-recoverable wastes were assessed for incineration with consequent heat recovery potential. Safe physico-chemical aqueous treatment processes for the final effluent then became minor and relatively cheap. An important factor in the total approach was to determine the cost-effectiveness of each recycling possibility. If internal use was not viable, then the marketing department attempted to find alternative outlets or, as a last resort, the energy value for steam co-generation by incineration was extracted. 

Taking into account the high amounts of wastewater produced by the process of extraction of olive oil, and their chemical composition, in this study, 22 wt % of olive wastewater (OW) or olive oil wastewater (OOW) was used instead of fresh water (FW) on the stage of compression or extrusion molding. The technological properties of the ceramic bricks with waste were compared with those with added fresh water, hi addition, the results obtained by extrusion and compression will be compared, in order to evaluate whether the waste bricks are attractive for an industrial implementation. The use of these effluents used to mix clays when preparing paste for bricks could provide a solution to an environmental problem. 

Removal of cesium from medium-level radioactive wastes involves extraction of cesium from aqueous solutions which are 1 M in HNO3 and 4 M in NaNOa (8). In a preliminary study, extraction experiments with ligands 1-7 were performed by mixing equal volumes (5 to 7 mL) of aqueous and organic solutions (calixarene 10 M in 2-nitrophenyl hexyl ether or 2-NPHE) in sealed polypropylene tubes for one hour at room temperal re (25 1 C). The aqueous solutions contained either NaNO or CSNO3 (5.0x10 M) in HNO3 (1 M) to assess the selectivity toward cesium in the hypothetical presence of sodium. A measure for the selectivity was assumed to be the ratio of the distribution coefBcients obtained separately for both cations ... 

Table 7 shows a summary of the findings of various sequential extraction studies on contaminated soils. The data from individual studies in Table 7 are averages of soil from more than one source. No studies of artificially spiked soils have been included, because they exhibit very different behaviour to waste site soils (Tuin Tels 1990). Despite the wide range of soil and contaminant sources included in Table 7 some clear trends are apparent. For example, extractable copper is mainly associated with the oxidiz-able phase, which may indicate that it is bound to organic matter (Cu can be strongly bound by soil organic matter Baker Senft 1995). 

Molten salt extraction residues are processed to recover plutonium by an aqueous precipitation process. The residues are dissolved in dilute HC1, the actinides are precipitated with potassium carbonate, and the precipitate redissolved in nitric acid (7M) to convert from a chloride to a nitrate system. The plutonium is then recovered from the 7M HNO3 by anion exchange and the effluent sent to waste or americium recovery. We are studying actinide (III) carbonate chemistry and looking at new... 

USEtox . In order to make sure that the results provided by USEtox are referred to China, the predicted emissions into the environmental compartments have been calculated using as a basis the information on the e-waste flow and presented in the chapter Tracking Global Hows of E-Waste Additives by Using Substance Flow Analysis, With a Case Study in China. Therefore these emissions are taken as inputs. Table 2 presents a summary with the main values extracted from the aforementioned chapter and used to run the USEtox model. 

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