polystyrene_Pollution-2520control&Safety.pdf

Please download to get full document.

View again

of 4
9 views
PDF
All materials on our website are shared by users. If you have any questions about copyright issues, please report us to resolve them. We are always happy to assist you.
Document Description
polution
Document Share
Documents Related
Document Tags
Document Transcript
  Production of Polystyrene _____________________________________________________________________44 Chapter 7 POLLUTION CONTROL AND SAFETY Waste products that are produced during the manufacture of Polystyrene: Polystyrene manufacture is a relatively clean process. Small volumes of liquidand gaseous wastes are generated and these are treated within the plants. Wastepolystyrene generated during production is reprocessed or sent to a recycler. Polystyrenemanufacture is a relatively clean process. Small volumes of liquid and gaseous wastes aregenerated and these are treated within the plants. Waste polystyrene generated duringproduction is reprocessed or sent to a recycler. This is a Most Energy-EfficientPackaging Material. Polystyrene is Safe, Hygienic Polystyrene and the Enemy of Bacteria Ease of disposal:  According to the U.S. Environmental Protection Agency (EPA) in the 1999 update of the Characterization of Municipal Solid Waste in the U.S. report, less than one percent(about 0.6 percent) of solid waste disposed of in the U.S. is polystyrene packaging -including both food service packaging (cups, plates, bowls, trays, clamshells, meat trays,egg cartons, yogurt and cottage cheese containers, and cutlery) and protective packaging(shaped end pieces used to ship electronic goods and loose fill peanuts ).The disposal of polystyrene is managed safely and effectively through the integratedsystem advocated by the U.S. EPA, which includes: Source Reduction, Reuse, Recycling,Waste-to-Energy Recovery, and Landfilling. Polystyrene safe to use in contact with food : For more than 40 years, polystyrene has been in widespread use as a hygienicmaterial for protecting and preserving food. In fact, one-reason polystyrene single usefood containers are so widely used in hospitals and other sensitive environment is that  Production of Polystyrene _____________________________________________________________________45they are significantly more hygienic than the alternatives. Polystyrene does not harbourbacteria, which is a major concern among health specialists.A recent American study shows that 1 in 7 reusable dishes harbour a level of bacteria which exceeds US health standards. In contrast, no disposable food serviceitems exceeded the standard. Foam Polystyrene – Presence of CFC’s:  Extruded foam polystyrene produced in for meat, chicken and vegetable trays andtakeaway food containers, does not use CFC blowing agents. Producers converted awayfrom CFC's in 1989 and now operate on recycled carbon dioxide or hydrocarbon gases.Expandable or bead polystyrene (EPS) such as in produce boxes has always used ahydrocarbon blowing agent. Reuse:  Reuse, the practice of utilizing polystyrene products in the same form, is important notonly because it delays the final disposal of a product, but also because it reduces themanufacture and purchase of new products. As a result, reuse prevents waste. Nearly 30percent of polystyrene loose fill (some times called peanuts because of its shape) isused again, making it one of the most commonly reused packaging materials in someretail locations. For mailing services, the reuse rate of loose fill is as high as 50 percent.The successful application of reused loose fill polystyrene reduced the demand for virginpolystyrene by 25 percent in 1997 alone and, to this day, continues to directly reducewaste.Other packaging and disposables commonly reused by the polystyrene industry include:pallets, insulated shipping boxes, test tube trays, auto part trays, ice chests and coolers . Recycling:  The recycling of polystyrene protective packaging and non-packaging polystyrenematerials, (such as audio/visual cassettes and agricultural nursery trays/containers) has  Production of Polystyrene _____________________________________________________________________46increased dramatically during the last decade and there has been a decrease in the amountof polystyrene food service packaging recycled during this period. Non-food servicepackaging is not contaminated with food and other wastes as is food service polystyrenepackaging, and therefore is more cost-effective to recycle. Presently, food servicepolystyrene packaging is generally not recycled because it is not economicallysustainable. It is important to note that because of unfavorable economics, no other post-consumer foodservice disposable material, including paper and paperboard, is recycled ina measurable way.Before 1988, there was essentially no recovery of post-consumer polystyrene forrecycling, but as of 2000, just twelve years later, more than 397 million pounds of polystyrene packaging were recycled. A portion of this material came from durablepolystyrene products such as coat hangers, compact disc jewel cases, single-usecameras and agricultural nursery trays.Some companies that make protective packaging are collecting it back forrecycling through the Alliance of Foam Packaging Recyclers. In addition, some makersof loose fill peanuts have set up a network of collection sites for reuse and recycling of their polystyrene products.Products that have incorporated recycled-content polystyrene include: foam eggcartons, lunch trays, transport packaging, audio and videocassette cases, office supplies,and building materials. Waste-to-Energy Recovery: In many overseas countries polystyrene is recycled through incineration of municipal waste for energy recovery. The burning of polystyrene is no more hazardousthan combustion of many natural organic materials. Polystyrene consists solely of carbonand hydrogen. When combustion is complete, water and carbon dioxide are given off,leaving trace levels of ash, the same combustion products as from paper or wood.While some polystyrene in medical an municipal wastes is currently incinerated inAustralia, the energy recovery option has not yet been implemented.  Production of Polystyrene _____________________________________________________________________47When incinerated, polystyrene produces energy, which compares favorably withcoal and oil. Because of its high fuel value, polystyrene in properly designed incineratorshelps to burn wet garbage more efficiently, and maintain the high burning temperaturesnecessary for safe combustion.The incineration of plastics can also generate energy and this potential is alreadybeing harnessed in some overseas countries, particularly in Western Europe, The UnitedStated and Japan. Land filling: While recycling and reuse continue to grow in popularity, most of the waste in thiscountry still goes to landfills. People assume the waste inside a landfill biodegrades. Butthe fact is that very little - not paper, not polystyrene, not even food waste - degrades in ameaningful way.Polystyrene is effectively and safely disposed of in landfills. Modern landfills aredesigned to protect the environment from the liquids and gases produced during the veryslow breakdown by reducing the exposure of garbage to air, water and sunlight -conditions needed for degradation. Therefore, by design, modern landfills greatly retardthe degradation process to reduce the by-products that might otherwise contaminategroundwater and the air. Preventing Litter : The polystyrene industry cares about the environment. A widely held misconception isthat litter is a problem caused by specific materials themselves rather than aberrantconsumer behavior. The reality is that some people improperly dispose of materials bylittering. Littering is a matter of behavior; people who discard materials into theenvironment usually do so because they don't think or don't care. Attributing the litterissue to one particular packaging material does not solve the problem because anothertype of packaging will take its place as litter unless behavior changes. To addressconcerns effectively, the polystyrene industry supports organizations such as KeepAmerica Beautiful, that work to prevent litter across the country .
We Need Your Support
Thank you for visiting our website and your interest in our free products and services. We are nonprofit website to share and download documents. To the running of this website, we need your help to support us.

Thanks to everyone for your continued support.

No, Thanks