Waste component ions

Ion exchange, reverse osmosis, ultrafiltration, and air stripping can also be used for separating waste components, especially for waste-water treatment. 

The predicted waste inventory for the repository indicates that potentially significant quantities of the organic ligands—acetate, citrate, oxalate, and EDTA—will be present (US DOE, 1996). Actinide interactions with these compounds were not considered in the speciation and solubility modeling, as calculations suggested that they would be mostly complexed by transition metal ions (Fe, Ni " ", Cr, and Mn " ") released by corrosion of the steel waste containers and waste components. A thermodynamic model of actinide-ligand interactions appropriate to brines will be included in solubility calculations for WIPP recertification. 

Waste Treatment. Environmental concerns have increased the need to treat Hquid discharges from all types of industrial processes, as well as mnoffs where toxic substances appear as a result of leaks or following solubilization (see Wastes, industrial). One method of treatment consists of an ion-exchange system to remove the objectionable components only. Another involves complete or partial elimination of Hquid discharges by recycling streams within the plant. This method is unacceptable unless a cycHc increase in the impurities is eliminated by removing all constituents prior to recycling. 

It may seem obvious but it is always worthwhile checking that the ions/decom-positions selected for monitoring are sensible with respect to the structure of the analyte(s) involved rather than waste time developing a method based on ions from a background component. 

Total or partial ion suppression is a well-known LC-MS effect, which is induced by coeluting matrix components that can have a dramatic effect on the intensity of the analyte signal. As can be observed in Fig. 1, analyte suppression occurs as a consequence of the different matrix interferences present in waste-water samples, making the identification and/or quantification process difficult or unfeasible. Even when working under selection ion monitoring (SIM) conditions, these matrix effects can cause ion suppression in the detection of some analytes that are present at low levels of concentration, as seen in this figure. Several papers have reported this effect [30-32] and different alternatives to overcome these problems, such as the inclusion of a size-exclusion step [33] or sequential SPE [28], have been applied for the determination of pesticides in... 

The entire system is based on a tiered approach where three layers of technology are integrated into the overall treatment system, as illustrated in Chart 2. First, a distributed process control system is network linked to the various component subunits of the waste management system such as pH control, ion-exchange control, tank level control, etc. Next, are the recovery/treatment processes themselves. The final tier is a monitoring system which controls both the performance of the treatment systems and the discharge assurance of the plant effluent... 

Three (3) classes of interactions can be described. First are the rapid reactions between soluble silicates and the polyvalent metal ions, producing insoluble metal silicates. Second, are reactions between the soluble silicates and the reactive components of the setting agent, producing a gel structure. Third, are hydrolysis, hydration, and neutralization reactions between the setting agent and the waste and/or water. 

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