Recycling contaminated material

A few special considerations must be dealt with when reusing PET from consumer sources in chemical recycling. For example, the PET must be clean and free of contaminating materials. Using plant scrap assures the manufacturers of both the identity of the resin and its purity. Using mixed colored resins may pose a problem, although when they are used in products that are not visible to the consumer, such as foam insulation, color is not a factor. 

During the B.E.S.T. process, oUy sludges, soils, and sediments are separated into three phases. These phases include a water phase that can be treated by conventional treatment and discharged a dry, treated solid phase that can be used as backfill on site and an oil phase containing the organic contaminants. The oil phase constitutes a small volume (relative to the initial volume of contaminated material) that can be destroyed or recycled. 

Tn municipal recycling contamination occurs whether or not vinyl is present. Other resins are just as much a contamination problem as vinyl. Except for commingled plastics applications, different plastic materials cannot be mixed successfully in most recycled products applications. This is why it is crucial to separate efficiently one plastic from another. 

Huber, M., and Franz, R. (1997). Studies on contamination of post-consumer plastics from controlled resources for recycling into food packaging applications. Deutsche lebensmittel-Rundschan 93(10), 328-331. (In Franz, R., and Welle, F. (2003). Recycling packaging materials. Ch. 23. In "Novel Food Packaging Teclmiques" (R. Ahvenainen, ed.), pp. 497-518. Woodhead, CRC Press, Boca Raton, FL). 

In practical terms, this means that the investigated recycling process is able to produce recycled PET material suitable for contact with foodstuffs, as long as an initial concentration of real contaminants of 500 ppm per substance is not exceeded. However, it must be stressed that 500 ppm represents an extremely high contamination of the PET material being returned for recycling (far higher than in practice). This... 

Waste that occurs during the manufacturing and processing of PS has practically always been fed/recycled back into the processing cycle. The reuse of municipal waste is feasible without any problems with uncontaminated and contaminated materials. Each is used in new market products. 

Adventitious contaminants Any unwanted substance that inadvertently comes into contact with the packaging material before it is collected for recycling and that therefore may contaminate the plastic and negatively influence the quality of the product filled by a recycled packaging material. 

The method of manufacture must ensure reproducibility between batches and the conditions should be chosen to preclude the possibility of contamination with other plastic materials or their constituents. Containers made should be similar in every respect to the type sample. For the testing on the type sample to remain valid, there must be no change in the composition of the material or in the manufacturing process, particularly with regard to temperature to which the plastic material is exposed during conversion or subsequent procedures such as sterilisation. Scrap materials should not be used. Recycling excess material of a well-defined nature and proportion may be permitted if the appropriate validation is carried out. 

The fast neutrons are very penetrating and may require some hydrogenous shielding for protection of operating personnel. Also, techniques to ensure low concentration of light-element contaminants in the recycled actinide material may be required. 

Finding AEA-10. A large inventory of silver is required for processing of chemical weapons, and finding an off-site recycler to accept the potentially contaminated materials could be a problem. 

The applications to recycling include use as an allowable material which would not hinder recycling (because it would be easily dissolved) and as a recyclable product. A PET beverage bottle which is afFixed with such a soluble film plastic label, cup adhesive and ink, would allow for less contaminant in the PET recycle. Contamination of paper label residue and adhesives is a problem with PET bottle recycling. This also allows for recycle of the adhesive and film by precipitation from the alkaline wash. 

ASTM X-95-3-1 Proposed Standard Guide for Determining Visible Contaminant Content of Recycled Plastic Materials (9/24/90)... 

After removal of all equipment, piping, and other contaminated materials, the walls and the ceiling of the building itself can be washed with high-pressure water. All water and treating solutions used during the decontamination process must be held and then treated before release. Water used in simple washing of surfaces can in many cases be recycled to reduce the volume of effluent. 

While many processes for using commingled plastics look at collection of bottles from curbside as the primary source of materials, they frequently combine these materials with industrial waste stream plastics, including coextruded scrap and other examples of multiresin, perhaps contaminated, materials. Other companies focus entirely on these types of waste streams. For example. Northern Telecom Ltd., based in Toronto, has a recycling facility for plastic reclaimed from wire and cable, along with materials from phone, fax, business machine, and pager equipment. The material, which contains small amounts of residual copper and aluminum, is used for truck mud flaps, flower pots, traffic stops, reflective bibs for construction workers, and other applications where high purity is not required,... 

In this paper we first review the practices of recycle and reuse of slightly contaminated materials from the nuclear industry and the disposal of very low level wastes from various sources and then discuss and present the criteria for release which have been used in different countries. Next the criteria which have been developed at the international level are presented and discussed. Consideration is then given to situations requiring environmental remediation and to the development of criteria for releasing such areas from regulatory control. 

Disposal in an approved, industrial landfill may be appropriate. Because this resin is inert and does not readily degrade, it will not contribute to instability of the landfill or evolve gases or leachates known to pollute water resources. DO NOT DUMP INTO ANY SEWERS, ON THE GROUND, OR INTO ANY BODY OF WATER. For unused or uncontaminated material, the preferred disposal waste management options are to send to a licensed recycler, reclaimer, or incinerator. The same waste management options are recommended for used or contaminated material, although additional evaluation is required. 

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