Author(s)

A. A. Siddiqui, W. Powrie, D. J. Richards

Abstract

One of the main aims of the EU Landfill Directive is to reduce significantly the landfilling of biodegradable municipal waste. Mechanical-biological pretreatment of municipal solid waste has become popular and is often adopted to enable compliance with this requirement of the Landfill Directive. This will have major implications for the nature of the waste that is disposed of to landfills and hence for the way in which the landfills should be managed. Pretreatment will cause changes in the composition and properties of the waste going to landfills including the gas generating potential, leaching behaviour and settlement characteristics. Germany has set strict allocation criteria for landfilling of mechanically biologically treated (MBT) waste. In contrast, there are no standards for MBT waste in the UK. Experimental studies were conducted to investigate the biodegradation and settlement behaviour of MBT waste samples treated to typical UK and German standards. The performance of large scale consolidating anaerobic reactors was monitored in terms of gas generating potential, leaching behaviour and waste settlement. The contributions of mechanical creep and biodegradation to secondary settlement were also identified.

Keywords

landfill, pretreated waste, leachate, biogas, waste settlement