Disposal methods recovered

Wastes contaminated with aniline may be Hsted as RCRA Hazardous Waste, and if disposal is necessary, the waste disposal methods used must comply with U.S. federal, state, and local water poUution regulations. The aniline content of wastes containing high concentrations of aniline can be recovered by conventional distillation. Biological disposal of dilute aqueous aniline waste streams is feasible if the bacteria are acclimated to aniline. Aniline has a 5-day BOD of 1.89 g of oxygen per gram of aniline. 

Good engineering prachce is to design chemical processes with an emphasis on recovering and reusing spent solvents [8]. However, not aU solvents will be recovered, and these will eventually need to be disposed. When disposing of solvent waste, there are several factors which must be considered to determine the appropriate waste heatment or disposal method. Some of these factors include the cost of disposal methods, overall toxicity of the waste, and environmental impact in the case of accidental and intenhonal releases. 

Off-site waste disposal methods involve the transfer of solvent wastes to an alternative location before their treatment, reuse, or release into the environment. One such method commonly used both on- and offsite is incineration. Solvent wastes are often incinerated, especially when they contain toxic substances and pose long-term EHS risks if directly released. The process of waste incineration releases a large amount of CO2 into the environment, but often the heat generated from this process may be recovered for use within a plant. When contaminated... 

We can not see any other way that such a process can become commercially viable. In the end, the right degree of competition is reached only if alternative competing technologies are properly costed in a sustainable manner. Currently, the cost of landfill disposal does not recover all costs to make this disposal method sustainable and in that sense landfill disposal is heavily subsidized. 

Sludges, such as those accumulated in the monoethanolamine or diethanolamine streams used for hydrogen sulfide removal by scrubbing, comprise another intractable waste material. Sludges may be reprocessed to recover valuable materials [79], or failing this they may be safely discarded by proper incineration. Others use landfilling (dry) or landfarming as disposal methods. Biotreatment or deep well disposal are also used, but to a more limited extent [80]. 

The valuable fertile elements are recovered from the acid solution by extraction with an organic solvent. The acid residue, containing the extremely radioaetive fission products, is processed to convert the waste into a stable solid form. The fission product waste, in a very concentrated form, is stored for ultimate disposal. This waste represents a different problem than the waste from current burner reactors. Because of the chemical concentration step there is less total mass of material. The same concentration process that reduced the mass of the waste concentrates the radiation produced into a smaller more intense package. This waste is so radioactive that it gets hot and must be actively cooled or diluted to prevent meltdown. Safe storage and disposal methods are very difficult to design. 

With appropriate funding, the Army estimates that the destruction of recovered chemical items can be completed within ten years, at a cost of 110 million. The Army believes that handling and disposing of recovered chemical weapons will be difficult as (1) they are more likely to have deteriorated than other nonstockpile materiel and (2) the identity of the agent is unknown in 25% of the weapons. The Army is studying several destruction options, including transportable incineration and neutralization systems. However, the actual method for destroying the recovered chemical weapons cannot be selected until after the Army completes the required technical and environmental studies. 

In addition, the Chemical Weapons Convention (1993) mandates requirements for chemical demilitarization. Congress began that effort in earnest with the EY 1993 Defense Authorization Act (PL 102-484), directing the Army to identify the locations, types, and quantities of all non-stockpile chemical materiel, explain disposal methods, estimate costs, establish a schedule for their destruction, and discuss transportation alternatives. Nonstockpile CWM includes buried CWM, binary chemical weapons, recovered chemical weapons, former production facilities, and miscellaneous CWM. 

Although there are minor differences in the HCl—vinyl chloride recovery section from one vinyl chloride producer to another, in general, the quench column effluent is distilled to remove first HCl and then vinyl chloride (see Eig. 2). The vinyl chloride is usually further treated to produce specification product, recovered HCl is sent to the oxychlorination process, and unconverted EDC is purified for removal of light and heavy ends before it is recycled to the cracking furnace. The light and heavy ends are either further processed, disposed of by incineration or other methods, or completely recycled by catalytic oxidation with heat recovery followed by chlorine recovery as EDC (76). 

Recychng (or reuse) refers to the use (or reuse) of materials that would otherwise be disposed of or treated as a waste product. A good example is a rechargeable battery. Wastes that cannot be directly reused may often be recovered on-site through methods such as distillation. When on-site recoveiy or reuse is not feasible due to quality specifications or the inability to perform recoveiy on-site, off-site recoveiy at a permitted commerci recoveiy facihty is often a possibility. Such management techniqiies are considered secondaiy to source reduc tion and should only oe used when pollution cannot be prevented. 

In terms of economics, it has been calculated that the capital cost requirement for a unit to recover bromine by this method is relatively low. Consideration of the operating costs shows that the cost of recovered bromine using this process is about 30 % of that for purchasing new bromine. This takes no account of the savings associated with not having to dispose of the bromide. 

Cold-pressed essential oils from the peel are some of the most important by-products recovered during the processing of Citrus fruits. The presence of limonene in the aqueous discharges, with its antimicrobial activity [1], decreases the effectiveness of the waste treatment system and increases the time necessary for the biological breakdown of the organic matter produced in the peel oil recovery system [2,3]. Additional recovery of essential oils from waste water would increase industry s returns and reduce the pollution problems associated with the disposal of waste water [4,5]. Several methods for reducing the levels of residual essential oils in the aqueous effluent have been developed over the years [6-11]. 

Industrial treatment plants may not be able to use their biological sludges as fertilizer or spread them on nearby fields if certain substances are present. They may be forced to dry and bum them instead. In some cases, as when heavy metals are present, they may have no recourse but to recover them or use deep-well or ocean-dumping methods. Often anaerobic digestors are used to reduce the amount of sludge and hence the size of subsequent equipment or the cost of ultimate disposal. 

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