Regional economic activities require materials that can be extracted domestically or imported from other regions. Analysis of optimal patterns of combined economic development and materials use should be discussed in relation to trade and the environment. A model is presented that optimises long-term welfare of a 2-region economic system with trade in virgin and recycled materials as well as co...

The purpose of this study was to investigate the relationship between strength and strain in manufacturing controlled low strength materials to recycle incineration bottom ash. Laboratory tests for controlled low strength materials with bottom ash and recycled in-situ soil have been carried out. The optimum mixing ratios were 25%-45% of in-situ soil, 30% of bottom ash, 10%-20% of fly ash, 0%-3%...

A key element for realizing long term sustainable use of any metal will be a robust secondary recovery industry. Secondary recovery forestalls depletion of non-renewable resources and avoids the deleterious effects of extraction and winning (albeit by substituting some effects of its own). For most metals, the latter provides strong motivation for recycling; for light metals, like aluminum, the...

The objectives of the study were: (i) to examine the efficiency of nutrient removal during the treatment of dairy farm effluent in a two-pond system, and (ii) to produce an inexpensive but effective nutrient trap which could be recycled as a nutrient source or soil mulch. The concentration of chemical oxygen demand (COD), biological oxygen demand (BOD), nitrogen (N), phosphorus (P) and potassiu...