Neutralization process testing

A series of batch reactor studies were conducted to validate the Blue Grass Chemical Agent Destruction Pilot Plant (BGCAPP) GB neutralization process (Malloy et al., 2007). Three different GB batches were used that had concentrations ranging from 75 percent to 90 percent, and di-isopropylmethyl phosphonate and the stabilizer compounds made up the remainder of the material. The batch tests used 6 percent sodium hydroxide the pH at the end of the batch runs was 12. 

Tubular glass containers are made in neutral type I, surface treated type I glass, soda glass, etc., and may also be siliconised as a separate process after manufacture. Surface treated type I glass is occasionally necessary in smaller containers, where now and then a sample fails the neutral glass test. 

The committee also believes that commercially available hazardous waste incinerators should be suitable for final treatment of neutralents, although test burns may be necessary. Some neutralents are high in sodium, which tends to shorten the life of the refractory brick used to line incinerators, but wastes of similar composition have been treated satisfactorily. Commercial hazardous waste facilities are available that offer other technologies that might be better for aqueous wastes. These technologies include biological treatment, supercritical fluid extraction (not to be confused with supercritical water oxidation, discussed later in this chapter) followed by incineration of the smaller volume of extracted organics, and chemically based proprietary processes. 

PMNSCM has proposed that plasma arc technology be used primarily for the destruction of neutralent waste streams, although it may be a candidate for the direct destruction of the binary CWM components DF and QL stored at Pine Bluff Arsenal. Based on the MGC/PLASMOX tests, the thronghput rate for neutralent processing is approximately 13 liters per hour, with a 50 percent availability. 

GENERAL INFORMATION The Surlyn brand of ionomers consists of copolymers of ethylene with methacrylic acid, partially or wholly neutralized with a variety of metals, including sodium, zinc, and lithium.The neutralization process drastically increases the melt viscosity and decreases the solubility, making molecular weight determinations of the final product impossible. However, the metal ions can be removed by treatment with acids, and the unneutralized copolymer examined by methods similar to those used for low density polyethylene (LDPE) and copolymers thereof. In certain cases, the properties of the ionomer resemble LDPE where applicable, these values are given in italics. About twenty grades of Surlyn plastics exist. Here we report on two representative samples sodium (Na) neutralized and zinc (Zn) neutralized. Where experimental conditions are described by a "D-" number, these refer to test procedures of the American Society for Testing Materials. 

Big River Zinc investigated two processes to dechlorinate the oxides. The first process used a water wash accompanied with a pH adjustment to minimize zinc losses. Htis method offered a known technology because Big River Zinc provided assistance to ZTT in Caldwell, Texas, to refine their similar process. Tests showed that washing, followed by neutralization with soda ash, succeeded in reducing the chloride content to less than 1% in the final product. The other process investigated was thermal dechlorination (4). It is known that thermal dechlorination can remove over 90% of the chlorides fiom roaster feeds. A few tests indicated promising results for this technique but the decision was taken to pursue washing as the process of choice. 

Problems associated with the stability of SCWO (e.g., maintenance of temperature and pressure for at least 20 hours, control of salt accumulation) appear to have been resolved for a test of SCWO processing of NaOH-based VX neutralents. In testing on materials of construction with this neutralent, salts accumulated at a rate of about one pound per hour, limiting runs with neutralent to 20 hours (runs with surrogate continued for about 40 hours) (Dekleva and Gannon, 2000). However, issues related to the mechanisms and locations of salt buildup, the chemical composition of the salts produced, and the effectiveness of flushing away salts are still unresolved. Pressure containment is another issue that must be addressed. ... 

This is an actual case history of the process upon which this test procedure was first tried. It was a neutralization process in which a reagent was being added to bring the effluent leaving a reactor to pH 7. The pH controller was in manual, simply because automatic control was unsatisfactory. 

The reaction is completed after 6—8 h at 95°C volatiles, water, and some free phenol are removed by vacuum stripping up to 140—170°C. For resins requiring phenol in only trace amounts, such as epoxy hardeners, steam distillation or steam stripping may be used. Both water and free phenol affect the cure and final resin properties, which are monitored in routine quaHty control testing by gc. OxaHc acid (1—2 parts per 100 parts phenol) does not require neutralization because it decomposes to CO, CO2, and water furthermore, it produces milder reactions and low color. Sulfuric and sulfonic acids are strong catalysts and require neutralization with lime 0.1 parts of sulfuric acid per 100 parts of phenol are used. A continuous process for novolak resin production has been described (31,32). An alternative process for making novolaks without acid catalysis has also been reported (33), which uses a... 

Flame Retardants. The amount of research expended to develop flame-retardant (FR) finishes for cotton and other fabrics has been extremely large in comparison to the total amount of fabrics finished to be flame retardant. The extent of this work can be seen in various reviews (146—148). In the early 1960s, a substantial market for FR children s sleepwear appeared to be developing, and substantial production of fabric occurred. In the case of cotton, the finish was based on tetrakis(hydroxymethyl)phosphonium chloride (THPC) or the corresponding sulfate (THPS). This chemical was partly neutralized to THPOH, padded on fabric, dried under controlled conditions, and ammoniated. The finish was subsequently oxidized, yielding a product that passed the test for FR performance. This process is widely preferred to the THPOH—NH process. 

The mechanical properties of ionomers can be appreciably altered by the manner in which the ionomer is prepared and treated prior to testing. Some of the factors that are influential are the degree of conversion (neutralization) from the acid form to the salt form, the nature of the thermal treatment or aging, the type of counterion that is introduced, the solvent that is used for preparation of thin films, and the presence and nature of any plasticizers or additives that may be present. In the scope of this chapter, it is not possible to provide a complete description of the influence of each of these variables on the wide variety of ionomers that are now commercially available or produced in the laboratory. Instead, one or more examples of the changes in properties that may be induced by each of the processing variables is presented and discussed. 

Real differences between the tensile and the compressive yield stresses of a material may cause the stress distribution within the test specimen to become very asymmetric at high strain levels. This cause the neutral axis to move from the center of the specimen toward the surface which is in compression. This effect, along with specimen anisotropy due to processing, may cause the shape of the stress-strain curve obtained in flexure to dif-... 

Tests should also be done in the presenee of organic matter (e.g. albumin) and in hard water. It is important to remember when performing viable counts that care must be taken to ensure that, at the moment of sampling, the disinfection process is immediately arrested by the use of a suitable neutralizer or ensuring inactivation by dilution (Table 11.4). Membrane filtration is an alternative procedure, the principle of whieh is that treated cells are retained on the filter whilst the disinfectant forms the filtrate. After washing in situ, the membrane is transferred to the surface of a solid (agar) reeoveiy medium and the eolonies that develop on the membrane are counted. 

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