Cleanup operations generally

Oil is a general term that describes a wide variety of natural substances of plant, animal, or mineral origin, as well as a range of synthetic compounds. The many different types of oil are made up of hundreds of major compounds and thousands of minor ones. As their composition varies, each type of oil or petroleum product has certain unique characteristics or properties. These properties influence how the oil behaves when it is spilled and determine the effects of the oil on living organisms in the environment. These properties also influence the efficiency of cleanup operations. This book deals specifically with crude oils and petroleum products derived from crude oils. The chemical composition and physical properties of these oils are described in this chapter. 

Emulsion breakers are not often used on open water or in cleanup operations in general because they have only recently been developed and tested and the formation of stable emulsions is not common. 

Suction hoses, pumps, vacuum trucks, and certain skimmers and sorbents, both natural and synthetic, are generally effective in removing excess oil from the surface, especially from ditches or low areas. The use of sorbents can complicate cleanup operations, however, as contaminated sorbents must be disposed of appropriately. Sorbents are best used to remove the final traces of oil from a water surface. Any removal of surface or vegetation also entails replanting and fertilization. 

The complexity of the solvent recovery operation depends largely on the mutual solubility of the two liquid phases. Cleanup is generally simpler and more economical if the two liquid phases are nearly immiscible, but more expensive and complex unit operations (e.g., extractive distillation) may be required if the two phases are partly miscible. Conunonly, aqueous raffinates are steam stripped to recover and recycle the solvent. 

The concept of a Type B(U) package is that it is capable of withstanding most of the severe accident conditions in transport without loss of containment or increase in external radiation level to an extent which would endanger the general public or those involved in rescue or cleanup operations. It should be safely recoverable (see paras 510 and 511), but it would not necessarily be capable of being reused. 

During remediation, contaminant levels decrease until they achieve an asymptotic level. Once asymptotic conditions are reached for several successive sampling periods, continuing remediation activities generally result in little further decrease in contaminant reduction. However, frequently when active remediation is halted, levels of dissolved contaminants abruptly increase (rebound). This increase is the result of the diffusion into solution of contaminants that were previously adsorbed onto the surface of the aquifer media. Sometimes more efficient cleanup is achieved by operating the remediation system on a cycle of several days on and several days off. Cyclic operation allows the operator to time the remediation to treatment of the higher rebound concentrations. 

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). 

A continuing source of concern is the operating pressure of an immunoaffinity column. Excessively pressures will generate shear-type forces that could cause destruction of the antibody-support bond and lower the efficiency of the column. In general, pressures should not exceed the value of 0.34. IO Pa to prevent loss of immobilized antibody (167). This condition meets the major restriction of all immunoaffinity cleanup procedures, which is the need to use aqueous extracts. Analytes extracted from the original sample with organic solvents cannot be... 

The primary coolant circuit of a PWR is shown in schematic form in Fig. 36. In this particular circuit, there are four loops between the reactor and the steam generators. The pressurizer is also shown, which maintains the pressure in the primary loop at a sufficiently high value (typically 150 bar) such that sustained boiling does not occur and maintains the desired concentration of hydrogen in the coolant. The reactor heat removal system (RHRS) and the reactor water cleanup system are not shown. The general operating conditions in a PWR primary loop are summarized in Table 2. 

Two commercial size plants for groundwater treatment based on liquid membrane technology in general, and the supported liquid membrane using hollow fibers in particular, were built and operated in Baltimore, U.S.A. Specifically, the purpose of the two plants is for hexavalent chromium cleanup. One plant went into commercial operation in March 1999 and the other approximately about a year later. The liquid membrane system in these two plants is able to reduce metal-ion concentration from 100-1000 ppm range to approximately 0.05 ppm and, meanwhile, produce a concentrated chromium solution, which is the spent strip solution, at approximately 20% Cr (VI). This concentration is suitable for sale for reuse. 

Recovery — In oil spill cleanup, this term applies to the entire process of physical removal of spilled oil from land, water, or shoreline environments, or any operation contributing to this process. General methods of recovering oil from water are the use of mechanical skimmers, sorbents, and manually by the cleanup crew. The main method of recovery of oil spilled on land or shorelines is by excavating contaminated materials. 

Soil washing is generally accepted as preferable to more conventional methods such as incineration for wastes where soil washing will provide cost-effective cleanup. The soil washing operation will have minimal effect on the off-site population or environment. However, soil washing produces a small volume of residual requiring further treatment or disposal. 

Another major cost driver is any time requirement placed on the cleanup process. Time constraints generally require the system to operate more aggressively driving up the cost of the remedy. Aggressive electrokinetic operation often requires greater electrode placement densities (i.e. smaller distances between electrodes) and consequently increased current draw and power consumption. If time is not a primary... 

These reports are generally honest in reporting past disposal practices based on interviews with current and former employees. They also contain detailed information about past facility operations. However, the people making these reports seldom—if ever— took soil, groundwater, sediment, or surface water samples and accordingly did not address the cleanup of past contamination, simply overlooking it. 

The second occurrence in this group is Sodium ingress in gas-type pressurizer through pipeline of primary sodium cleanup system and blow-down pipeline of failed MCP-2 while primary sodium cleanup system was being connected to the primary circuit (FIG.4). The primary sodium cleanup system, connected with pipelines with pipelines of loops-2 and 3, is general for all sodium coolant of primary circuit. Loop-2 was on maintenance and separated from primary circuit with isolation gate valves N 1,2. When personal began to put into operational primary sodimn cleanup system, it was fed from pressure pipeline of MCP-3... 

Tyvek provides an ideal balance of protection, durability and comfort of any limited use fabric technology. Protection is built into the fabric itself there are no films or laminates to abrade or wear away. Applications include lead and asbestos abatement/remed-ation, general maintenance/operations, spray painting, general cleanup. DuPont, www. tyvekx om, (800) 44-TYVEK. CIkIb 2S0... 

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