Welcome to the May 2011 issue of Waste and Resource Management. This issue of the journal opens with a briefing (Burton, 2011). The author describes the application of the Contaminated Land Applications in Real Environments definition of the waste code of practice designed to negate adherence to the more cumbersome waste management licensing and environmental permitting regime with reference to the clean-up of the Avenue coking works. This briefing provides a valuable summary of the compliance difficulties of the regulatory regime and a succinct illustration of the benefits of the waste code of practice in terms of limiting the burden to regulators in the use of waste material exemptions.
The first paper by Jolly et al. (2011) is the remaining contribution to the February special issue of the journal (164.1) on the theme of geophysical methods in landfill waste. It provides a very detailed account into the use and interpretation of electrical resistivity measurement techniques to determine the movement of leachate within a landfill. Importantly, it highlights the considerable care necessary to interpret accurately artifacts arising from the inversion process applied to the raw data. This technique is then used to assess leachate movements within a waste mass accounting for the effects of waste degradation on leachate resistivity.
The paper by McLeod and Cherrett (2011) appraises the capabilities and limitations of automated vehicle routeing and scheduling methods to optimise waste collection. A number of practical considerations are discussed relating to the need for detailed local knowledge, vehicle access and ‘tipping points’ (the point on the round where the collection vehicle needs emptying). Case studies are used to highlight vehicle mileage savings of approximately 6%.
Kepp and McKendry (2011) characterise the impact of the front-end separation of recyclates, prior to biological treatment processes, on the eventual quality of the refuse-derived or solid-recovered fuels. The paper highlights the importance of the decision to incorporate (or otherwise) plastics into the fuel product.
The final paper by Al-Akhras et al. (2011) reports the results of a laboratory study into the curing, leaching and structural properties of mortar incorporating a medical waste ash as a partial replacement for silica sand. Results show that very limited leaching of heavy metals occurred and that setting times reduced with increasing medical waste ash content. Compressive strength was generally enhanced although flexural strength decreased with increasing ash content. This careful study highlights the potential benefits in using recovered materials in construction. It is contributions of this type that are needed to allay concerns related to compliance with specifications and standards.
These papers provide a broad and varied insight into a range of waste management issues and practices not immediately identifiable with mainstream civil engineering. It is this scope and general quality that is establishing Waste and Resource Management as a leading archival source for the dissemination of all aspects related to construction and the resource management cycle and to socio-economic and sustainability issues.
