Subjects
ADMINISTRATION
Next week there will be a full day field trip for Waste Technology. We will be leaving at 9.15am and will be visiting Cellulose Valley, the Lismore Landfill, and Ballina Landfill and MRF. You will need to bring suitable footwear, sun/wind/rain protection, writing equipment, calculators, and food. We will stop for lunch in Ballina. There are compulsory Problem Set question based on this activity.
What is recycling?
What is main source of recyclables in Australia?
Recycling involves processing waste to produce a useable raw material or product. Recycled material can, in principle, be re-used many times (a product made from recycled material often can itself be recycled), unlike material which has been burnt to have the energy recovered from it or composted. For example, most of the gold that has ever been refined is still in use around the world. It has a high value relative to the costs of collection and processing, unlike many wastes. In many cases materials best suited for composting, recycling or incineration are mutually exclusive and the issue of competition between these options does not arise.
Historically significant components of the waste stream have been recycled in one form or another. The rag and bone men were recyclers. Many kids used to collect newspaper and sell it to the butchers or fish and chip shop for wrapping paper. Torn-up newspaper or telephone directories have been used for toilet paper. Kids billy carts were made from wheels of old prams or lawnmowers. Nowadays, packaging manufacture uses 30% recycled material. About 30% of the UK steel output is from reclaimed material. About 50% of industrial and commercial plastic in Australia is recycled (<1% of domestic).
The price and availability of virgin raw material has been a powerful commercial driver for recycling, but market imperfections and barriers have sometimes acted to discourage businesses from exploiting the potential of recycling to the full.
Householders have shown a willingness to sort glass, newsprint, plastic and aluminium, but are unwilling to clean steel food cans. This growing community involvement has also been encouraged by local government through the establishment of collection and/or dropoff schemes. About 60% of councils throughout Australia are involved in the collection of recyclables. There is no doubt that governments can engineer higher recycling rates. But should they? Would it make the community better off, both economically and environmentally?
Paper
The main opportunity to increase the volume of paper recycling is to make newsprint using old newspapers and magazines. New de-inking and recycling plants have been established, but they won't help paper recycling much outside the east coast of Australia. About a third of waste newsprint recovered in Australia is exported for recycling overseas, and remains the preferred disposal outlet for some supplies. There has been a small but increasing quantity of high quality paper being used in the manufacture of printing and writing papers.
Plastic
New investments have been made in plastic recycling, especially for PET, HDPE and PVC.
By taking these initiatives, firms have set out to forestall what they have seen to be more costly government initiatives such as container deposit legislation or mandatory recycling requirements. In South Australia, deposit legislation has applied to certain containers since 1975. While reuse of glass bottles is high in that State, the container deposit arrangements inhibit the use of other beverage containers which could be recycled and may reduce incentives to collect a wider range of used household materials.
Large quantities of recyclable materials still remain in the waste stream. However, greater recovery of paper, glass, aluminium and plastics could make only a limited contribution to reducing waste as these materials make up a comparatively small proportion of the waste stream. A major inroad would require more recycling of industrial waste, organic materials such as garden refuse, and building materials.
In 1989, government waste management authorities, primarily local Councils, disposed of 12.8 million tonnes of waste. About 3 per cent was diverted to recycling. Amongst the potential benefits of recovering more of this waste are the avoidance of waste disposal costs, including a reduced call on increasingly scarce landfill space near major cities. Recycling is also a useful means of preventing pollution from waste.
Many Councils and waste management authorities may not be charging enough to cover the real costs to the community of waste disposal and provide for site replacement and environmental costs. If the charges for waste disposal are too low, there is an incentive to discard rather than recycle used materials. Disposal charges in Sydney, Melbourne, Brisbane and Perth -the major recycling centres - have been increasing in response to the higher costs of new landfill sites and tighter environmental requirements. This trend is expected to continue. Rising costs will increase the incentives to divert materials for recycling.
The net costs to Councils of arranging for the kerbside collection of recyclables can be set against the avoided costs of waste disposal. In many parts of Australia these costs are likely to be low, but they exceed $30 per tonne in inner Sydney and Melbourne. Some Councils, particularly in Melbourne, have spent more on developing and running recycling schemes than they have saved through avoided disposal costs. Ratepayers may of course support these higher levels of recycling, but at present few ratepayers would be aware of the real costs of waste disposal or the real costs and benefits of recycling schemes.
Charges for industrial waste are normally levied according to the quantity. In most Australian cities, charges for liquid wastes and some solid wastes such as tyres vary with the type of waste and the cost of treatment. This provides a direct link between the waste generated and the cost of disposal. However, if the charge is less than the real cost of waste disposal, including environmental costs, too much waste will be disposed of and recycling will not be encouraged.
Charges for household waste collection are normally levied through property rates. Waste charges therefore bear no relationship to quantities or types of waste and there is no direct financial incentive for households to reduce waste. This means that firms and households have very different incentives to manage their waste efficiently.
Recycling can defer or avoid altogether some waste materials entering the natural environment. For instance, in Australia the recycling of about 90 per cent of old car batteries avoids some dangerous pollution in landfill. Used oils, solvents and many other chemicals and dangerous substances are treated for further use. Until such time as the use of CFCs (chlorofluorocarbons) is eliminated, recycling of CFCs can avoid further damage to the ozone layer.
Recycling can also help in litter abatement, but bigger anti-litter gains may be achieved by other means. Problems of plastic in the marine environment, for instance, are not likely to be overcome by recycling. Compared with production from virgin materials, the processing of recovered materials can lead to less use of energy and less pollution. This is because reprocessing starts with a material which is already refined.
Energy savings are possible through the recycling of many materials from many sources. Indeed, the savings in energy during reprocessing help to determine whether the recycling of many products is commercially worthwhile. But the manufacturing stage is just part of the process. A considerable part of the energy needed to recycle paper, for example, is in collecting and transporting the wastepaper. Thus, striving for uniform levels of recycling, regardless of location, does not make good economic or environmental sense.
Recycling can reduce the emission of greenhouse gases. Whether the benefits are significant in global terms, or there are more effective ways of reducing these emissions, are issues which extend well beyond this report.
The reprocessing of recovered materials is not always pollution free. Certain reprocessing technologies create residues which are difficult to treat. The acid-clay process for rerefining waste oil is one example where the residual sludge has contaminated land. Whether the use of recycled material is less polluting than virgin material can only be assessed on a project by project basis.
The effects of de-inking and repulping wastepaper are relatively benign, using currently available technology and modern inks which do not contain heavy metals, but de-inking does produce salt in effluent. The location of de-inking facilities and the policies adopted to manage salinity problems are therefore important in assessing the environmental effects of paper recycling.
The costs of collection, transport and reprocessing may be a disadvantage. This also results in higher costs for recycled materials.
The emphasis upon packaging means that a great deal of effort goes into extending the recycling of materials which account for only one tenth of total urban waste by weight. It also means that the focus is upon products such as PET bottles which are conspicuous in litter, even though they form a small part of the waste stream and do not have major adverse environmental effects. Some of these recycling schemes may bring no net gain to the community.
Although recycling in Australia is primarily in the hands of the private sector, governments at all levels have some influence:
Inappropriately priced services (electricity, transport, water supply) or resources (minerals, forests) can influence incentives to re-use waste materials rather than virgin materials. Whether this favours or penalises recycling, there is a cost on the community.
Table 1: Recovery Rates (%) Source: Australia Industry Commission 1991 Recycling Report
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Aluminium |
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Lead |
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Copper |
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Steel |
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Glass |
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Plastic |
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Paper |
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Lubricating oil (a) |
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Organic waste - household |
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Tyres (b) |
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a) About half the oil consumed is not available for recycling
b) Proportion of used tyres recovered for retreading
Aluminium
Aluminium accounts for only 1.5% by weight (more by volume) of household waste. Two thirds of this is beverage cans. About 31% of aluminium produced is recovered for reprocessing or exported as scrap. Beverage cans are recycled at a rate of 62% - one of the highest in the world. The world recovery rate for aluminium is 26%. Aluminium scrap prices are volatile and vary with quality. Aluminium produced directly from bauxite requires substantial energy inputs, including about 24% being for electricity. Smelting secondary aluminium only requires about 5% of that needed for primary production, but this doesn't take into account the energy used in collection and transport.
Lead
Lead accounts for less than 1% of the waste stream, but the associated disposal problems are large. It is present in a variety of products and can present contamination problems because of its toxicity. The recovery rate for lead is about 60% compared to a world average of about 50%. About 90% of the lead scrap produced in Australia arises from lead-acid batteries in vehicles. Lead recycling leads to some conservation of resources. For example, smelting primary lead is associated with the production of large quantities of sulphur dioxide. Much of this is recovered and converted into sulphuric acid. No significant sulphur dioxide production is associated with smelting secondary lead. There are of course considerable environmental benefits with recycling of lead.
Steel
Steel accounts for about 1 to 5% of household waste - mostly containers and domestic appliances. The recovery rate for scrap steel is about 26%, but there is significant in-house industrial recovery of around 40%. Because of the high values of scrap steel the recovery rates are relatively high, but while the technology exists to recycle virtually all steel, the costs may be greater than the benefits. Many steel products now contain plastic coatings which must be removed before smelting. This process is costly. The amount of steel cans recovered from domestic scrap is virtually nil. It has been estimated that each person generates about 13.8kg of steel (mostly cans) per year. This means that in a city of 100 000, 1380 tonnes of steel scrap would be generated. BHP has said that this sort of quantity is too small to be of economic interest, mainly because of the shredding and transport costs.
Smelting steel scrap results in less air and water pollutants than from the production of new steel. However, environmental regulations and the use of scrubbers in new steel furnaces limit the release of air pollutants and hence limit the gains in this respect from recycling steel.
Glass
About 25% of all glass containers sold are recovered for reprocessing, and a further 11% are recovered for reuse at least once. This compares with recovery rates of about 15% in the USA. Most glass bottles in Europe and Japan are refillable, and the Netherlands has over 90% of softdrink and beer sales in reusable containers as required by law. In Japan some 66% of bottles are reused. In the UK recycling from glass has increased from 17% in 1989 to 29% in 1993, with a commitment to 58% by the year 2000.
Refillable glass bottles can be reused for about 20 trips, but these are heavier bottles. Non-refillable bottles are generally about 30 to 40% lighter. South Australia, with container deposit legislation has the highest recycling rates of 51%. Among the benefits of glass recycling is the energy saving which is 50% lower for reprocessing than for new glass from raw materials. There are also benefits in litter reduction. This has to be balanced against the costs of collection, treatment and reprocessing. A further cost is the pollution arising from cleaning reusable bottles. The energy savings come from the fact that the presence of at least 15% cullet reduces the energy requirements. Each 1% increase of cullet reduces energy requirement of about 0.4 to 0.6%. There is also a decrease in natural resource requirements - sand, soda ash and limestone.
Plastic
Around 15% of plastic waste is reprocessed in Australia, with the vast majority of it coming from commercial and industrial sources. Estimates in 1989 showed about 0.5% of domestic plastic is recycled. In the USA about 1% of domestic plastic is reprocessed, though 10% of PET is recovered. In Europe plastic is included in packaging and a recovery target of 50 to 65% has been set for the year 2001, with a recycling target of 25 - 45%. However, plastic is an important source of energy in incineration in Europe.
The considerable complexity of plastics is one factor which limits the recycling potential. The different types and the mixtures make recycling a problem. The low intrinsic value and the high volume per weight makes collection and transport a major cost factor. The reprocessing of plastics can save energy. For example, the energy required to produce HDPE from virgin materials is 1.9Mj per litre, compared with 0.1Mj per litre for reprocessed HDPE. However this doesn't take into account the costs of collection and transport, and when these are included the margin is much closer. (Accurate figures not available because of variability).
Other Items
Electric and electronic equipment. This includes white goods such as refrigerators and Tvs and computers. We don't have figures for Australia, but in the UK some 12million tonnes of these items end their life each year. There are now programmes being developed for stripping and recovering materials for recycling.
Oil.
About 35% of lubricating oil is recovered for reuse - mostly as a fuel. Only 3% is re-refined into lubricating oil. In Australia about 469 000tonne of lubricating oil is sold. Of this some 49% (230 000t) consist of products that do not generate waste oil, or are lost through combustion, on car parts, consumed in rubber manufacture etc. This leaves 239 000t of potentially recoverable oil. Of this about 84 000t was recovered, leaving some 155 000t not recovered. Given the potential for environmental damage of such a large amount, it is a potential major problem. Quite a lot of this oil is probably from owners changing their own car engine oil. UK figures show that only 50% of DIY oil is recovered - and the collection of oil is well established in the UK, with drums available at most dropoff centres - something which doesn't happen in Australia.
Recycling must be considered in its place in the waste management hierarchy - it is the last step before disposal to landfill. Clearly, recycling has been effective in some key areas, especially aluminium cans and glass, but there is still the problem of costs and benefits, and the difficulties of measuring some of them. This a just a brief overview, and I hope you will look at the handout from yesterdays lab session for some specific examples.
Further Information
The following books are on Reserve in the Library (Consult your Administration Booklet for full details) Charles, (1991); Diaz et al. (1982); Lund (1991); Rhyner et al. (1995); and Waste Recycling & Processing Service of NSW (1992). You should also consult the Residua/Warmer Bulletin. Another web site with information is the Recyclers World
Next Week
The Lab Session this week examines recycling and resource conservation. In next weeks lecture we will look at composting and the Group Project Presentations are due on Friday.