Abstract Society uses metals derived from primary and secondary sources. Secondary sources include all metals that have entered the economy but no longer serve their initial purpose. The environmental benefits of increasing reliance on secondary metal production include conserving energy,...

Methane gas is a by-product of landfilling municipal solid wastes (MSW). Most of the global MSW is dumped in non-regulated landfills and the generated methane is emitted to the atmosphere. Some of the modern regulated landfills attempt to capture and utilize landfill biogas, a renewable energy...