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Questions and AnswersMaterial and material processing questions andOther Material Resource Issues
The problem with plastics is that they come in many different types from hard plastics to plastic film which have different properties and must be segregated to enable reuse as a raw material. Plastic bottles (PET and HDPE) are the easiest plastics to recycle and Project Integra is currently one of the largest recyclers of these items in the country. The bottles, which are collected with other co-mingled recyclables in most areas and taken to a materials recovery facility for separation, are then sent to a reprocessor which granulates them, the granules then being used to manufacture items such as fleece jackets. Recycling other types of household plastics is currently not practicable because of a lack of markets and on cost grounds. Since January 2002 European Union regulation has required the removal of ozone depleting substances (ODS) (including CFCs and HCFCs) from commercial and domestic refrigeration equipment before it can be disposed of. The UK was rather caught out as the new regulations were deemed by the EC to apply to ODS in the insulating foam and well as in the refrigeration coolant. No plant to extract ODS from the foam existed in the UK when the regulations first came in, leading to the much publicised ‘fridge mountains’. However, a number of firms have since invested in plant in the UK and there are also cost-effective options involving use of European facilities. Once the ODS have been removed from fridges the recyclable elements are recovered and any residues sent for disposal. Further information is available from: www.defra.gov.uk/environment/waste/topics/fridges/faq.htm
All forms of asbestos can be carcinogenic. All asbestos is classified as a special/hazardous waste and is generally regarded as not being suitable for recycling. Because of the difficulties associated with waste asbestos, special arrangement/procedures must be adhered to when handling and disposing of it . Landfill sites accepting asbestos must be licensed for the purpose.
Recycling construction and demolition waste is a very good means of directly reducing the need for primary aggregate material. Recycled materials have to be ‘fit for purpose’ and for this reason inert/stable materials such as rubble, bricks, glass etc. are most suitable for use as recycled aggregate. Materials that are potentially hazardous or otherwise contaminated cannot be used unless the Environment Agency are satisfied there is no danger to health or the environment. There are a range of other restrictions and barriers to aggregate recycling including the economics, lack of awareness and information, and compliance with established specifications. However, there is evidence that these issues are gradually being overcome and the amounts of recycled aggregates are increasing. As an example, Hampshire County Council is working with contractors Raynesway Construction and Foster Yeoman to increase the recycling of materials arising from highway maintenance across Hampshire. This work has included setting up new transfer stations to store the material until it can be reused, a review of working practices and specifications for construction. The results to date have been very encouraging.
It is very difficult to gauge how much construction and demolition waste is recycled simply because of the difficulties surrounding the collection of such data. That being said it is estimated that in 2001, 45 million tonnes of construction and demolition waste was produced in England and Wales, with 38 million tonnes (84%) being used as recycled aggregate. Further information on a survey carried out by Government on Arisings and Use of Construction and Demolition Waste in England and Wales in 2001 (ODPM 2002) can be obtained from: http://www.odpm.gov.uk/stellent/groups/odpm_planning/documents/page/odpm_plan_606333.hcspAs part of the Hampshire Natural Resources Initiative, funding has been secured under the Department of Trade and Industry ‘Partners in Innovation’ scheme for demonstration project to optimise construction waste usage over a defined geographic area (Hampshire). The project is being managed by an organisation called Viridis and includes a range of public and private sector partners. The project will start towards the end of 2003.
This is a difficult question to answer as to some extent, all waste management activities have a degree of environmental cost. Moreover, much depends upon the type of recycling activity being implemented - materials requiring greater pre-treatment prior to recycling would have greater environmental costs attached to them than materials that require little or no pre-treatment through increased energy costs or increased water use. Additionally, when considering the true environmental cost of recycling, other factors must be taken into account such as how far the waste has had to travel before reaching its recycling point and how it has been transported. The location of the markets for the materials’ re-use (once recycled) is another factor that could potentially have a strong bearing upon the true cost of a recycling process. These are all factors that will vary from one recycling operation to another. Some academic research suggests that in some cases the overall impacts from recycling certain products make recycling a less sustainable option than utilising virgin materials to manufacture them, or recovering the energy locked up in them once their useful life is over. However, analyses of this type are highly dependent on where the boundaries are drawn, and in some cases fail to take account of the wider societal implications of materials consumption. The reality is that in many cases scientific data are inadequate and methodologies are insufficiently well defined to reach any formal conclusions. Even when rigorous approaches are adopted, the scale, complexity and long-term nature of the issues may put the validity of the answers in doubt. Given the above situation, a pragmatic response is to act upon the general policy direction being cascaded through European and UK Government legislation that is based on the premise that, in general, recycling is an environmentally attractive option where it is practicable to recover materials in a way that meets the requirements of sustainable end markets (and of course that those markets are available).
Some CO2 emissions arise from recycling, including the associated transportation. However, the important point is that recycling generally results in a reduction in CO2 emissions overall compared with the use of virgin raw materials. For example it has been estimated by the European Commission that recycling one tonne of paper saves 900 kg of CO2 equivalent over the production of virgin paper. The corresponding figures for PET plastic (used for the production of some plastic bottles) and aluminium are 1800 kg and 9,100 kg respectively.
Traditionally incinerators in the UK have been used to burn and derive energy in the form of electricity from municipal/household waste, clinical waste and other special wastes such as animal carcasses. Such installations are however, also capable of handling industrial and commercial waste, particularly where it is of a similar nature to household waste as it does not make sense to try and burn C&I waste with a high non-combustible content. The proposed MRS principles suggest that the general approach should be to maximise, as far as practicable, the segregation of key resource streams such as bio waste, paper, plastics, metals, etc. The aim should be to treat each segregated stream or sub-stream by the most appropriate means, be it materials recycling, bio-treatment or thermal processing. For the mixed residual waste that cannot be practicably separated, the options in realistic resource management terms are biological treatment or thermal treatment in preference to landfill. A rigorous analysis of the options along these lines should help to establish the need for any future additional incineration or other energy from waste capacity.
There are four existing/planned incinerators in Hampshire. Three are municipal waste incinerators recovering energy by way of electricity generation. The plant at Chineham near Basingstoke is operational and the other two (at Marchwood near Southampton and in Portsmouth) are under construction and due to be commissioned in 2005. The three incinerators have a combined capacity of 460,000 tonnes. This is equivalent to 51% of current municipal waste arisings (the vast majority of which is household waste). The other incinerator is a long established hazardous waste incinerator at Fawley with a capacity of 30 000 tonnes per annum.
We are not sure which materials are being referred to
here and would be pleased to Other material resource issuesThe wider definition of "natural resources" includes everything from:
The problem is that under the above definition, "natural resources" covers a very broad spectrum. It is important that we do not ‘bite off more than we can chew’ and remain focussed to achieve the key changes people want to see. For that reason the term "Material Resources" has been adopted. This means that our work will be focussed on minerals, manufactured materials and the consequent waste. However, linkages with water (e.g. in terms of pollution from waste), soil (e.g. the use of compost as a soil enhancer) and energy (e.g. utilising waste as an energy source) must be fully explored. Separate initiatives are dealing with the wider aspects of water, soil and energy and more information on these can be made available (see www.hnri.org.uk). |
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