In 1985, the scrap tire industry was created when Minnesota became the first state to develop specific legislation and regulations for scrap tires. Up to that time, many scrap tires, like most solid and household wastes, went into the l1)unicipal dump. Those tires not placed in the dump went into stock piles, some of which still exist today. Prior to 1985, few, ifany scrap tires were processed....

Hexavalent chromium is highly toxic to most living organisms and a known human carcinogen by the inhalation route of exposure. Therefore, treatment of Cr(VI) contaminated wastewater is essential before their discharge to the natural water bodies. Cr(VI) reduction to Cr(III) can be beneficial because a more mobile and more toxic chromium species is converted to a less mobile and less toxic form....

In the current recycling system of end-of-life (EoL) appliances, which is based on shredding, alloying elements tend to end up in the scrap of base metals. The uncontrolled mixing of alloying elements contaminates secondary metals and calls for dilution with primary metals. Active disassembling fastener (ADF) is a design for disassembly (DfD) technology that is expected to solve this problem by...

Different cyanogenic bacterial strains (Chromobacterium violaceum, Pseudomonas fluorescens, Bacillus megaterium) were cultivated under cyanide-forming conditions in the presence of metal-containing solids such as nickel powder or electronic scrap. All microorganisms were able to form water-soluble metal cyanides, however, with different efficiencies. C. violaceum was able to mobilize nickel as ...

There are various approaches to sorting alloys. Perhaps the most simple method and one which is in greatest use today is hand sortation, which is normally a rather inaccurate process. An opportunity exists to recover lowgrade nonferrous scrap by sorting it into various alloys with high accuracy by applying spectrographic analysis techniques. This article presents an alternative method for scrap...

An investigation was conducted to determine the influence of recycled scrap tire rubber on the engineering properties of controlled low strength material (CLSM). With control over the ultimate compressive strength of CLSMs being key for applications such as backfilling utility trenches where re-excavation is often necessary, incorporation of scrap tire rubber into the CLSM mixture is a viable w...

A mixed integer non-linear optimization problem has been developed to aid in purchasing scrap steel. The model, which includes about 600 real-valued variables, 200 integers, and over 800 possible constraint equations, uses industrial data, actual market prices and supplier information to perform calculations. Prices, quality and supplier information are input or read into the model, along with ...

This study examines the effect of waste and recycling policy on scrap prices and the importance of scrap price feedbacks as a determinate of the costs of waste and recycling policy. The effects of a deposit/refund, advance disposal fee, and recycling subsidies on scrap prices are derived, and the direct and indirect channels of waste reduction are decomposed for the three instruments. Scrap pri...

Laboratory studies were conducted to investigate scrap-tire-shreds as a potential alternative to conventional gravel in the drainage layer of leachate collection system at the base of landfill. Performance of various physico-chemical characteristics of leachate after passing it through combined bed of scrap-tire-shreds and gravel for different combinations of thickness of scrap-tireshreds and g...