Drum disposal

The washed solvent is collected in drums for disposal. The aqueous stream, after analysis, can be sent directly to the publicly owned treatment works (POTW). Limits have not yet been set for dumping versus waste disposal in drums. If the solvent being used is a regulated substance (such as toluene), drum disposal of the HLO may be the only acceptable way. 

Hazardous Wastes Hazardous Wastes for deliveiy to a treatment or disposal facility normally are collected by the waste producer or a licensed, speciahzed hauler. Typically, the loading of collection vehicles is completed in one of two ways (1) wastes stored in large-capacity tanks are either drained or pumped into collection vehicles, and (2) wastes stored in sealed drums or other sealed containers are loaded by hand or by mechanical equipment onto flatbed trucks. To avoid accidents and possible loss of life, two collectors shoiild always be assigned when hazardous wastes are to be collected. 

Where relevant, procedures for disposal of containers, e.g. aerosol dispensers, drums when empty. ... 

Closed Disposal System - This is the discharge piping for a PR valve which releases to a collection system, such as a blowdown drum and flare header. However, a closed system can also be a process vessel or other equipment at a lower pressure. 

Conventional Flare System - The majority of pressure relief valve discharges which must be routed to a closed system are manifolded into a conventional blowdown drum and flare system. The blowdown drum serves to separate liquid and vapor so that the vapor portion can be safely flared, and the separated liquid is pumped to appropriate disposal facilities. The blowdown drum may be of the condensible or noncondensible type, according to the characteristics of the streams entering the system. Selection criteria, as well as the design basis for each type of blowdown drum, are detailed later in this volume. The design of flares, including seal drums and other means of flashback protection, is described later. 

This chapter covers the design of facilities to handle equipment drainage and contaminated aqueous effluents that are sent for appropriate disposal blowdown drum systems to receive closed safety valve discharges, emergency vapor blowdowns, etc. and facilities for process stream diversion and slop storage. Also covered are criteria for selecting the appropriate method of disposal. Design of flares is covered in a subsequent chapter. 

Safety valve releases are routed to blowdown drums when the presence of liquid, toxic properties or other factors would make discharge to the atmosphere hazardous. Product and intermediate process streams may need to be diverted to alternative disposal if they are off-specification (e.g., during startup) or in the event of emergency shutdown of downstream equipment. 

Aqueous Drawoffs from Hydrocarbon Vessels - Water or aqueous materials that are withdrawn continuously or intermittently from vessels where they directly contact hydrocarbons (e.g., process water from distillate drums, and spent wash water or spent caustic solution from settlers) must be disposed of in such a way that entraimnent or inadvertent withdrawal of hydrocarbon will not create a hazard. Disposal is therefore a function of hydrocarbon category, as follows ... 

The purpose of a blowdown drum is to disengage closed safety valve releases and various drainage, blowdown and diverted materials into liquid and vapor streams which can be safely disposed of to appropriate storage and flaring facilities, respectively. Entrainment of liquid hydrocarbons into a flare stack is not acceptable, since the potential exists for burning liquid falling onto the ground or adjacent facilities. For this reason, a blowdown drum is required. 

Usually, the closed liquid drain header is run as a separate line to the drum and provided with a high level cut-off valve with local manual reset. In some cases the closed drain system is segregated into a number of subheaders, as described earlier. Hydrocarbon liquids may be bypassed around the drum through a connection from the closed drain header directly to the pumpout pump suction, provided that the liquid can be routed to a safe disposal location, considering its vapor pressure and temperature. Emergency liquid pulldown connections, if provided, are routed to the blowdown drum via the closed drain header. 

If the drum may occasionally receive water, caustic or similar aqueous streams, which would create problems in receiving facilities if pumped out with the hydrocarbon, then means of separate drainage should be be included. This may consist of a connection to the sewer from the bottom of the boot or in the case of sour water, a connection off the pumpout pump discharge routed to sour water facilities or other suitable disposal. 

Aqueous plant effluent and drawoff streams such as steam condensate, sour water, or spent caustic soda solution may require disposal to a disengaging drum. 

Liquid hydrocarbons accumulated in non-condensible blowdown drums, originating from safety valves, closed drain headers, knockout drum drainage, etc. Facilities are normally provided at the drum for weathering volatile liquids and cooling hot liquids before disposal. 

If HjS is continuously present in the flare gas or if the flare seal drum also functions as a sour water disengaging drum, then the effluent seal water must be routed to a sour water stripper, desalter, or other safe means of disposal. Withdrawal from the drum is by pump in place of the normal loop seal arrangement. Two pumps are provided one motor driven for normal use, and the other having a steam turbine drive with low pressure cut-in. The seal drum level is controlled by LIC with high and low alarm lights plus an independent high level alarm. 

Disposal of effluent water from multijet ground flare seal drums should comply with paragraphs (1), (2), and (3) above, except that ... 

Relieving vapors from various pressure-relief and depressuring valves in the system must be collected in individual flare headers that should be appropriately located near each process area. Subheaders must be interconnected to a main flare header which feeds to a knock- out drum and disposal system. Condensates that are carried over by vapors are separated in the knock-out drum. The vapors that exit the vessel go to the flare stack where they are burned. 

Personnel and equipment need to be decontaminated in the CRZ. However, the CRZ might be a small area immediately adjacent to the remediation area, which workers are aware of, and is also marked appropriately. Although the CRZ is less formal and likely does not have many decontamination stations, efforts should be made to make sure that personnel and equipment are appropriately cleaned. Many times, due to the logistics of a smaller job, disposal of wastes becomes difficult. If purge water is drummed and left on the site, it is imperative that it is identified, labeled properly, recorded in the site log, and disposed of in the proper manner (in accordance with applicable, local, state, federal, or other regulations). 

The Brio refining site is approximately 58 acres in size and is the location of a former chemical production, recovery, refinery, and regeneration facility. The site includes closed impoundments into which hazardous substances were disposed in bulk, storage tanks, and approximately 1,750 drums of hazardous substances. Remediation activities included the excavation and incineration of contaminated soil, installation of protective liners around selected pits, and the installation of a groundwater extraction system adjacent to a gully. 

FIGURE 17.30 This 35-year-old drum of radioactive waste has corroded and leaked radioactive materials into the soil. The drum was located in one of the nuclear waste disposal sites at the U.S. Department of Energy s Hanford, Washington, nuclear manufacturing and research facility. Several storage sites at this facility have become seriously contaminated. 

Local ones are listed in the yellow pages of the telephone directory. The laboratory operator should contact more than one for suggestions and estimates. In such discussions, a disposal service vdll ask detailed questions as to the exact nature of the waste and quantities involved. An agreement will be made about the types of shipping containers to be used. These are non-returnable. The disposal service may sell suitable containers and require these for certain types of waste. In other cases, the laboratory may provide its own. If drums are needed, they are available from companies engaged in drum reconditioning. Manufacturers of chemicals may have used drums available at reasonable prices, but since these wdll contain residues of their former contents, a check for compatibility must be made before using them. 

In the past, small quantities of liquid waste, in drums, has been disposed of by dumping at sea or in land-fill sites. This is not an environmentally acceptable method and is now subject to stringent controls. 

Cost of NaOH USDl.OO/kg and NaOCL USD2.35/kg. c Cost of disposal USD1.84 /kg of sludge (USD400/drum) 30% solids content. 

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