Cleanup operations methods

Initially, the oil must be contained and its horizontal and downward movement stopped or slowed. Containment methods are difficult to implement and may cause physical damage to the site. Digging an interceptor trench can be effective in reducing horizontal spread. Such trenches are filled in after the cleanup operation to restore the natural drainage patterns of the land. Another method is to place walls around the spill source to stop its spreading. These can be slurry walls consisting of clay or cement mixtures that solidify and retain the oil, or solid sheets of steel or concrete can be positioned to retain the oil. 

This chapter deals with the problems associated with safe and efficient cleanup operations. It addresses process planning, the cleaning process itself, the problems of changeover, and methods of equipment preparation. 

The use of a drain system permits the quick construction of a collection/removal system which also serves as a barrier for leachate from large, shallow sites. At the Sylvester hazardous waste site in Nashua, New Hampshire, a groundwater interception and recirculation system was installed as a method to retard further spread of the leachate plume until a remedial cleanup action could be implemented. The system was operated for 1 year until a containment wall and cap were constructed over the 20-acre site (McAneny, 1985). 

Many natural products are charged substances, and can be isolated by IEC methods. Dufresne has published a comprehensive review describing various resins and column operating conditions applicable to purification of natural products from fermentation broths or crude extracts.168 Among natural products, antibiotics are of special interest due to their widespread use in humans and animals. Sample cleanup by IEC prior to analysis by other LC methods for quantitative determination of antibiotics in biological fluids is frequent.I69171 Also, IEC followed by TLC appears useful for the quantitation of fumonisin Bl, a mycotoxin found in agricultural products.172... 

Linking TLC with a tandem instrument differs from combining GC or LC with an appropriate spectrometer. Hyphenation of planar chromatographic techniques represents a niche application compared to HPLC-based methods. Due to the nature of the development process in TLC, the combination is often considered as an off-line in situ procedure rather than a truly hyphenated system. True in-line TLC tandem systems are not actually possible, as the TLC separation must be developed before the spots can be monitored. It follows that all TLC tandem instruments operate as either fraction collectors or off-line monitoring devices. Various elaborate plate extraction procedures have been developed. In all cases, TLC serves as a cleanup method. 

Achiral-chiral multidimensional chromatography remains one of the best ways to separate chiral analytes from interfering matrix components or other compounds. The flexibility offered by different operation modes, stationary and mobile phases, and configurations allows analysis methods to be tailored to the analytical problem. By offering possible configurations for both online sample cleanup and concentration, achiral/chiral LC/LC reduces manual sample preparation. The ability to be coupled to... 

Therefore, in this chapter we describe major refinery operations and the products therefrom and focus on their composition, properties, and uses. This presents to the reader the essence of petroleum processes, the types of feedstocks employed, and the product produced, as well as warning of the types of the chemicals that can be released to the environment when an accident occurs. Being forewarned offers an environmental analyst the ability to design the necessary test methods to examine the chemical(s) released. It offers environmental scientists and engineers the ability to start forming opinions and predictions about the nature of the chemical(s) released, the potential effects of the chemical(s) on the environment, and the possible methods of cleanup. 

Several other methods have been published using RP-HPLC for the determination amphetamines and related derivatives. Studies have shown the determination of amphetamine and related derivatives in plasma, urine, and hair by RP-HPLC with precolumn derivatization and either UV/VlS or fluorescence detection. Various methods are employed by SPE technologies using Cl8 cartridges for sample cleanup prior to derivatization. The derivatized compounds were separated on analytical columns of various Cl 8 bonded phase materials. The methods generally used water/acetonitrile mobile phases operated in gradient mode. All studies reported extraction recoveries of 85-102% for all the analytes, with LLOQs ranging from 5 to 60 ng/ml (Tedeschi et al., 1993 Ealco et al., 1996 Hernandez et al., 1997 Al-Dirbashi et al., 1997 Al-Dirbashi et al., 2000 Soares et al., 2001). 

The interlaboratory results obtained from the analysis of defined standard solutions, but also from the analysis of sediment extracts prepared either by the coordinator of the study or by the participants themselves, also provide a measure of the variation between laboratories. The results show that the interlaboratory reproducibility ranges from 6.5% for the defined dioxin sample to 27.9% for the sediment sample extracted by the participants themselves. As was mentioned before, the reproducibility for this last sample is relatively high and most presumably due to the introduction of extra handlings (extraction and cleanup) to the total procedure. In addition, the fact that not all the participants had prior experience with the extraction protocol to be used could have added to the increase in variability of the process. Furthermore, the dilution factor was not dictated. This also introduces a certain degree of variation. For the reproducibility of the DR CALUX bioassay itself and not caused by differences in operating extraction conditions, the maximum variation between laboratories was observed to be 18.0%. The results for the sediment extract samples can also be used to estimate the method variability for extracts, that is, based on samples of unknown composition. Again, given the intra-as well as the interlaboratory variations observed in this study, it appears justified to conclude that the standard deviation of the means provides a reasonable estimate of the method variability, based on the overall aver-... 

The most recent modification of the NBD-Cl method involves a further improvement in its qualitative support (616). It involves the infusion of the extract employed for thin-layer chromatography via an electrospray interface into a mass spectrometer operating in the multiple-stage mass spectrometry mode, thus allowing confirmation of suspect results. The cleanup of the thyroid gland samples was also performed with a selective extraction procedure, based on the specific complex formation of the thiouracil, methylthiouracil, propylthiouracil and phenylthiouracil, tapazole, and mercaptobenzimidazole residues with mercury ions bound in a Dowex 1-X2 affinity column. 

When the employee begins working, the focus should turn to the safe operation of equipment and proper materials handling and spill cleanup procedures. Techniques should be demonstrated for minimizing the amount of material allowed to escape and the human exposure to it. Employees should also be taught the signs and methods of detecting the release of toxic material into the work environment. 

Equipment procedures documentation of safety precautions and step-by-step methods for equipment setup, operation, and cleanup... 

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