Sustainable municipal solid waste (MSW) management is regarded as one of the key elements for achieving urban sustainability via mitigating global climate change, recycling resources and recovering energy. Landfill is considered as the least preferable disposal method and the EU Landfill Directive (ELD) announced in 1999 requires member countries to reduce the volume of landfilled biodegradable materials. The enforcement of ELD initiated the evolution of MSW management system UK. This study depicted and assessed the transition and performance of MSW management after the millennium in Nottingham via materials flow analysis (MFA), as well as appropriately selected indicators based on the concept of waste management hierarchy and targets set in waste management regulations. We observed improvements in waste reduction, material recycling, energy recovery, and landfill prevention. During the period 2001/02 to 2016/17, annual waste generation reduced from 463 kg/Ca to 361 kg/Ca, the recycling and composting share increased from 4.6% to 44.4%, and the landfill share reduced from 54.7% to 7.3%. These signs of progress are believed to be driven by the ELD and the associated policies and waste management targets established at the national and local levels. An alternative scenario with food waste and textile separation at source and utilizing anaerobic digestion to treat separately collected organic waste is proposed at the end of this paper to fulfil the high targets set by local government and we further suggest that the recycling share may be improved by educating and supporting the public on waste separation at the sources.

Since the enforcement of the EU Landfill Directive, EU waste directives were successively enforced in EU member states to facilitate the establishment of sustainable MSW management.Various changes have been made in England to reduce the global impact of its MSW management, but the effectiveness of these changes on mitigating the global warming potential (GWP) from MSW management has never been investigated in detail. This study assessed the historical GWP of MSW management in Nottingham throughout the period from April 2001 to March 2017 through life cycle assessment (LCA). The LCA results indicate continuous reductions in greenhouse gas (GHG) emissions from MSW management during the study period due to improvements in waste collection, treatment and material recycling, as well as waste prevention. These improvements resulted in a net reduction of GHG emission from 1076.0 kg CO 2 -eq./t of MSW (or 498.2 kg CO 2 -eq./Ca) in 2001/02 to 211.3 kg CO 2 -eq./t of MSW (or 76.3 kg CO 2 -eq./Ca) in 2016/17. A further reduction to -142.3 kg CO 2 -eq./t of MSW (or -40.2 kg CO 2 -eq./Ca ) could be achieved by separating food waste from incinerated waste, treating organic waste via anaerobic digestion and by pretreating incinerated waste in a material recovery facility.

Urban forests can provide the necessary ecosystem services for their residents and play an important part in improving the urban environment. Forest landscape connectivity is a vital indicator reflecting the quality of the ecological environment and ecological functions. Detecting changes in landscape connectivity is, therefore, an important step for providing sound scientific evidence for the better urban planning. Using remote sensing images of a study area in Zhuhai City in 1999, 2005, 2009 and 2013, the dynamic forest landscape connectivity of Zhuhai city can be evaluated based on a graph-theoretic approach. The aims of our study were to discover and interpret the effect of rapid urbanization on forest landscape connectivity. The construction of ecological corridors helps us specifically compare the landscape connectivity of three parts of urban forests. On the basis of functional landscape metrics, the correlation of these metrics and patch area was discussed in order to comprehensively identify the key patches. The analysis showed that the total areas of forestlands reduced from 1999 to 2009 and then increased from 2009 to 2013, and the same trend was found in overall forest landscape connectivity. To improve the overall landscape connectivity, construct urban ecological network and appropriately protect biodiversity in the future, the existing important patches with large areas or key positions should be well protected. This study revealed that urbanization reduced the area of key patches and consequently reduced the forest landscape connectivity, which increased while the patch areas increased due to the environmental protection policy. Functional connectivity indicators could provide more comprehensive information in the development of environmental protection strategies.

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