Spills and Overflows

Spills or overflows that occur while filling containers, drums, trucks, or tanks will create a fire hazard. If such a spill should occur, prompt action is necessary to remove possible sources of ignition such as automotive engines. If the spill occurs adjacent to fired heaters or other static ignition sources, then consideration should be given to shutting them down until the spill has been cleaned up and/or foam has been applied to the spilled materials. 

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Texaco ended operations in Ecuador in 1992. Oil spills and overflowing waste pits had contaminated the land and the drinking water. The company says that it compiled with all rules in force at the time. It attributes many of the spills to natural disasters. The jury at the International Water Tribunal in Amsterdam found that large quantities of hazardous waste entered the soil and water with at most superficial measures to minimize spills and contamination.184... 

In order to handle accidental spills or overflows, a spill basin maybe provided, into which the flow is diverted if the concentration of a particular constituent exceeds a predetermined value. If equalization precedes biological treatment, in addition to the organic loading, high fluctuations in temperature, salinity, and toxic organics must also be considered. After the spill is contained, the wastewater flow is diverted back to the equalization basin. The contents of the spill basin are then pumped at a constant controlled rate to the equalization basin. 

Many times operators are asked only to "operate", that is, to perform certain functions by rote. Whether or not actions have consequences other than completing the workday is not in the scope of work. While expensive and difficult, this option can be seen as a keystone concept in many operations, for no equipment, no process, will be any better than the operator assigned to it. Therefore, at a minimum, operators should understand the consequences of spills, leaks and overflows, the destination, both immediate and eventual of all wastes, and their part in the process of waste generation. 

Guerin (2) has reported an average annual oily wastewater loadings from mining operation of about 140 kL/d. Clearing of spills, leaks, and overflows with floor wash down accounts for 60% of the operations oily wastewater. Composition of oily wastewater from mining operation reported by site locations is shown in Table 2. 

If there is a breach in the fluidic system, containment of spills and leaks is critical to limit exposure to dangerous reagents. Spills and leaks can be contained by the use of trays or overflow containers and doors. The... 

Another form of control involving material transfer is the use of containers to collect overflow spills and the leaking of materials when transferring from one container to another. Safety planning and practices for commonplace tasks need to be as thorough as for operation with unusual hazards. 

Where corrosive liquids are frequently handled in open containers or drawn from storage vessels or pipelines, are adequate means readily available for neutralizing or disposing of spills or overflows, and performed properly and safely ... 

A large gas line is present in the top cover to duct dilution gas, noncondensable offgas, and steam to the adjacent quench tank. The quench tank provides a mass of water to condense transported steam and to cool other gases. Condensate spills over and is collected in the overflow tank. The quench tank has a cooling coil to maintain the water inventory in a subcooled state. The cooling coil, quench tank, and overflow tank are instrumented with flowmeters, thermocouples, level sensors, and pressure transducers in order to monitor the transient state of the system and extract the necessary heat balance information. Downstream from the quench tank is a spray tank which performs a redundant quench/gas cooldown function. While adding redundancy, the use of two quench tanks in... 

Blockage of liquid Monitor pressure drop across vent system (e.g., effluent line due local indication, alarm or interlock) to closed valves,, Interlock valve in feed line to centrifuge results in flooding of basket and Equipment/line-up checks overflow from Remove unnecessary valves basket to solid col-. 5, lection system in base. Possibility of liquid spill. ... 

Wastewater, which is a basic source of emissions, can be categorized in five ways (1) wastes containing a principal raw material or product (2) by-products produced during reactions, (3) spills, leaks, wash downs, vessel cleanouts, or point overflows, (4) cooling tower and boiler blowdown, steam condensate, water treatment wastes, and general washing water and (5) surface runoff. 

Assessing the effects of enclosures or vapor boxes is similar to assessing the effects of vapor fences. Consider the case of a typical dike sized to hold 110 percent of the liquid spilled. For small releases, the dike walls would act as containment or storage for the vapor generated shortly after release occurred. The vapor that would be generated by evaporation or boiling from the dike floor would displace the air in the dike for a given period of time and then overflow the dike walls. The vapor holdup duration is easily estimated ... 

In the second type, the injector unit contains a device called a loop, which is a coiled tube of precise volume. The loop is loaded with sample, and once filled, its contents can be injected onto the column. It is always necessary to overfill such a loop to ensure complete loading. To overfill, the loop is loaded with sample until it overflows the excess sample spills out one of the injection valve vents. Although injectors differ in the amount of overfilling required, experience leads us to recommend overfilling by as much as 30%, since it is critical to load the injector loop completely. Partially filled loops will result in abnormal chromatographic profiles. There is waste with injectors of the type shown in Figure 4.1 IB, and if material is in short supply or expensive, the type of injector (Fig. 4.11A) might be preferred. 

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