Why Are Cities Planting Fast Growing Trees?

Most attention on recycling tends to go to materials produced by man – plastics, paper and electronics are probably the big three issues. That’s not the end of the story though. Trees and other plants make up a large percentage of what we throw away. According to EPA figures yard trimmings account for 13.5 percent of municipal solid waste – 110 pounds of grass clippings, old pot plants and dead Christmas trees for every American per year. Then figure in lopped branches from forestry, unharvested parts of crops and the huge amount of plant matter disposed of by the food industry and we’re talking about millions of tons of plant matter to be disposed of every year. If left to decompose it will release huge amounts of carbon into the atmosphere, so sending it to landfill counts as a very bad idea. What gets done to it instead?

Fast Growing Tree Trunk

Large public works projects such as roads and commercialized areas require the clearing of land. This is usually in the form of vacant forests of varying sizes. All of the trees and plants that are cleared get filtered to their respective industries; large trees get sourced for timber while the remaining shrubs and smaller plant material is filtered down the recycling line. Environmental advocates have pushed hard for reforestation bills that ensure whatever trees are cut down are replaced so that there is almost no negative environmental impact. Many municipalities have enacted laws such as these and are considered 1 for 1: however many acres of forest are cut down, they replace that same amount of land with new saplings to regrow the forest. Because the goal is to reforest cheaply and quickly, municipalities choose from a list of fast growing trees for their area so that the saplings mature quickly to continue pulling harmful greenhouse gasses such as CO2 from the air. Although these bills are not nationwide, they are quickly taking hold as more and more cities adopt these laws. So what happens with the actual trees and plants that are cut down and discarded?

Tree Farm

Probably the most valuable resource in plant waste is wood. What goes for recycling isn’t usually good enough quality to be used for timber or furniture, otherwise it would be used in those industries, but it’s still wood and it can be processed into several useful products. The basic way of processing it is by chipping. Foliage is stripped away and the wood is mechanically reduced to small chips of varying sizes. Where it goes from there depends on the type and quality of the wood. Softwood can be fully pulped and turned into paper, although most of the demand for that is met by recycling existing paper or wood from managed forests. Chips can also be formed into wood-based construction materials like particle board, which is cheaper than solid timber and performs better in many applications. It also reduces the need to cut forests for raw materials. Lower grades of particle board can be made from much of the wood sent to recycling.

Wood chips, waste and pulp

Another option that’s becoming more popular is biomass power. This is a fuel source, usually used for electricity generation, which exploits organic waste. Wood and a wide variety of other materials, including spent sugarcane, can be chipped and burned as a fuel in suitable boilers. This then generates steam, which turns a turbine to create electrical power. With carbon sequestration equipment fitted this is a low-pollution and sustainable method of generation that doesn’t use up scarce fossil fuels.

As well as wood there are huge quantities of soft plant matter to consider. The most efficient way to use this is through composting. By managing the decomposition of plant material a rich natural fertilizer can be produced. This has been done for thousands of years by simply piling waste in a heap and keeping it damp, but industrial processes have now been developed. Stricter control of the process improves the quality of the compost and also minimizes the emission of greenhouse gases like methane. The largest stainless steel building on the continent is a composting plant in Alberta, Canada; it’s the size of 14 NHL rinks and every year it turns 250,000 tons of waste into 80,000 tons of compost.

Tree and plant waste is produced in huge quantities and can be bulky, but because it’s all natural material it can be recycled using low-tech and usually economical methods. However it is carbon rich, which is potentially a serious environmental hazard. Properly managed, though, it’s a valuable resource and one that’s being exploited with increasing efficiency.

Recycling Gold, Silver & Other Precious Metals

For centuries, man has had an undying relationship with precious metals. These metals like gold and silver are prized not only for their beauty but also value. This is the only logical explanation for the high number of gold and other precious metals that can be found sitting in central bank vaults and jewelry boxes. According to U.S Geological Survey, there is roughly 171,300 tons of gold that have been mined in history. This is rising at a high rate of 3000 tons every year.

silver-recycling2

While nothing is wrong with gold, its mining is very bad for our environment. For every ring of gold, there are roughly 20 tons of toxic wastes being generated. And the toxic substances used in the process of mining the gold like mercury and cyanide pollutes both the air we breathe and the water we drink. In fact, gold mining is the number one source of mercury pollution. It is even ahead of coal-fired power stations.

Therefore, we cannot possible continue enjoying these precious metals when they wreak havoc on our planet. Options include using mining methods that are more eco-friendly. This might mean stopping dumping the toxic wastes into oceans and rivers or stop using things like mercury and cyanide. However, the best solution is recycling of the gold that we have already.

Silver recycling

Silver is normally found in electronic and electric scrap, photographic wastes, coinage and jewelry. Given that silver is used for several different things, recycling it is very important. The demand for silver increases as the population grows. Many ways exist to enable reusing and recycling of silver. They include the following.

Scrap Silver

silver_bars-recycled

The simplest way to recycle silver and turn it into silver bars.  Your local coin & bullion shop can assist you with this.  To view the types of silver bars that can be made with your unused silver, check out the photos & resources at www.goldeneaglecoin.com.

Selling or donating

If you have a silver jewelry, consider selling it to any jewelry store or even donating it to an organization. This way, the silver will be reused. Alternatively, the jewelry store could melt and recast it to form new jewelry.

Continue reading “Recycling Gold, Silver & Other Precious Metals” »

Recycling Industrial Waste Products

Industrial wastes if left unattended to can cause a lot of damage. Recycling industrial waste products makes a great impact in the world. It helps preserve the natural environment for ourselves and our future generations. It is apparent that the more years go by, the more the need for better management of waste products. This is because as the wealth increases, people buy more products and create waste. When the population increases, it means there are more people to create more waste.

Lifestyle changes such as fast food and new packaging and technological products are developed, meaning more products are more biodegradable. There are regulations that are in place to demand that industrial companies are recycling their wastes rather than disposing them off and damaging the environment.

History

The practice of recycling is no recent phenomenon. There are claims of the practice dating back to Plato in 400 BC. At this time household wastes such as broken pottery and tools were recycled because resources were limited. They were thus reused when new material was unavailable.

Before the industrial period, scrap bronze and other metals were collected and melted for reuse. Dust and ash from coal and wood were recycled as a base for brick making. In these times, recycling offered and economic advantage.

Industrialization catapulted the need for affordable materials. This is why scrap metals were sought after more than virgin ore. The railroads from the 19th Century to the automobile industry of the 20th Century, there was a need for the utilization of scrap metal. Peddlers made a living collecting pots, pans, machinery and sources of metal from dumps, city street and even door to door. This especially became more rampant during World War I.

Continue reading “Recycling Industrial Waste Products” »

Go Green & Recycle Glass

Glass_Recycling

Most of the inorganic waste in our homes can be recycled which is good news for the environment and all of us in return. The worrying trends of global warming, depleted ozone levels and air pollution are making the scenes of the After Earth movie appear more and more realistic. Recycling glass is pretty easy as it can be recycled an infinite number of times without it losing its quality, purity or strength. It is one of the most widely recycled materials with some countries like Belgium, Finland and Switzerland recycling over 90% of their glass and the UK recycling more than 50% of their container glass. In the US 5% of the garbage is made up of glass.

 

History

Recycling is not a new concept but rather one that has been around since the BC era. Archeological evidence uncovered over time shows that in the imperial Byzantine times, glass was recycled in the Sagalassos, the ancient city that is present day Turkey. Recycling of other materials like bronze coins and metals and using them to create other items like statues or weapons was a common practice in those periods. Even before the industrial revolution which made recycling a trend, recycling was still being practiced because it made economical sense to recycle some materials instead of using virgin material. Recyclable materials like aluminum and glass were used until they became too worn to be of any further use. In Britain, bricks were made using dust and ash as their base materials and scrap bronze as well as other metals in Europe were melted down and recycled in a perpetual cycle.

After the establishment of the environmental movement which was established in the 1960s, recycling became popular resulting in the establishment of drop-off recycling centers. A major milestone in the journey of recycling was covered when a universal symbol for recycling was introduced. The symbol was a Mobius strip which was designed in the later half of the 1960s by Gary Anderson. This was after a recycled-container company which was based in Chicago sponsored an art contest that was aimed at raising environmental awareness. The triangle has been used as a representation of the hierarchy of recycling that encourages people to reduce, reuse and recycle. The interest in recycling was also increased because of the rising energy costs that were being witnessed in the 1970s.

Continue reading “Go Green & Recycle Glass” »

Recycling IP Addresses

When we talk about recycling we usually mean physical goods and the materials they contain. In the modern connected world these aren’t the only valuable resources though, and there are others that might lack physical existence but are still finite and need to be conserved. One of the most important is IP addresses.

Most modern computers, tablets and smartphones use the TCP/IP protocol to communicate and share data with each other, and this set of standards is built around the concept of IP addresses. A traditional IPv4 address consists of four numbers, separated by periods; each number can be anywhere between 0 and 255. In fact the whole IP address is a single 32-bit number that can be broken down into subnets or operated as a single large network. Each device on the network needs to have a unique IP address; for it to work properly duplicates cannot exist. The problem is that using a 32-bit number means there are a total of about 4.3 billion addresses available – and the pool of available ones is running out.

When the IPv4 standard was written in 1981 it was hard to believe there would ever be so many connected devices, but the unbelievable has become reality and in fact the 4.3 billion limit has already been exceeded. To keep the internet working some hard work has been necessary. The main effort has been towards developing and deploying IPv6, which uses 128-bit addresses and so offers 3.4×1038 unique identifiers – enough for every person on earth to have millions of devices. However many systems still depend on the older technology, so it’s vital to get the most possible use out of the existing pool.

One common technique is Network Address Translation, or NAT. This allows multiple devices to connect to the internet through a single external IP address. There are limitations to NAT, because it doesn’t always allow end to end connectivity between individual devices, but it can significantly increase the number of consumer devices that can be operated. Most broadband routers function as NAT systems – there is one IP address that connects to the internet, but a large number of devices can be connected downstream using private IP addresses (usually 192.168.xxx.xxx).

Larger-scale efforts are also being made to free up addresses. Many large blocks were previously allocated to organizations that aren’t using all of them, and the body that allocates address space, IANA, has the option of reclaiming and reissuing all or part of these blocks. There are technical issues with this, because some hardware isn’t set up to use certain address ranges, but it could potentially add up to a billion more addresses.

The IPv4 address space can’t last in the long term – whatever measures are taken the growing number of connected devices, especially the always-on ones envisaged for the “internet of things”, will exhaust the supply. The future lies with IPv6. In the meantime, however, clever use of NAT and reclaimed address blocks should keep things going until the newer protocol becomes more widespread.

Recycling Cataytic Converters

Since the 1970s catalytic converters have helped to dramatically improve air quality, particularly in urban areas. As well as turning highly toxic carbon monoxide into inert carbon dioxide they eliminate emissions of unburnt fuel from the exhaust, breaking it down into water and more carbon dioxide. While carbon dioxide emissions have their own issues the immediate problem is much less than spewing out carcinogenic hydrocarbons. Newer models also deal with nitrogen oxides, converting them to oxygen and harmless nitrogen gas. The effect on pollution levels has been dramatic.

Of course any technology also presents some challenges, and catalytic converters are no exception. In this case the main one is the value of the materials they contain. As well as their basic structure, which is usually a metal casing holding an internal structure of heat-resistant ceramic or kanthal, there’s the catalyst itself. This is where most of the potentially reclaimable value of the device lies.

When exhaust gases enter the converter they’re channeled through a matrix of fine channels, lined with the metal catalyst. The catalyst, together with heat supplied by the exhaust system itself, promotes the chemical reactions that turn pollutants into less harmful atmospheric gases. A variety of metals are suitable for use in converters but most of them have some disadvantages, such as longevity or the possibility that under some running conditions new toxins could be created. The three most effective and reliable ones, however, are platinum, palladium and rhodium. These are all precious metals with a value of hundreds, or even thousands, of dollars an ounce. It’s obviously not cost effective to discard them when a vehicle is scrapped. Both to recover value and preserve limited resources, the catalyst needs to be recovered for reuse.

The recycling process begins when either a car is scrapped or an old converter is handed in to a specialist for exchange. There are a number of businesses which specialize in recycling them but a similar process is used throughout the industry. First the casing is cut open and processed as normal scrap. The internal components, which carry the catalyst in foil form, may consist of beads or a lattice. However the foil isn’t pure catalyst; it also incorporates the “wash coat”, which ensures that exhaust gases are evenly spread over the catalyst. Often this is bonded to a ceramic substrate.

To begin the separation process the wash coat and substrate are pulverized, usually with a hammer mill; the result is a fine powder. The wash coat, which is mostly aluminum, is removed by dissolving in caustic soda. Non-metals like ceramic can usually then be floated out, or the metal content removed by dissolving in a strong acid (which the ceramic resists). The precious metal content is then removed from the solution. This can be done by precipitating it out chemically, but a more effective method is electrolysis – a current is passed through the solution between two electrodes, and the catalyst will be deposited as a pure metal around one of them.

A new technology is currently being developed in Japan, based on the plasma arc furnaces that are widely used for processing electronics scrap. This system employs rapid, extreme heating followed by quenching in cold water. The process separates the catalyst from the substrate and wash coat, greatly reducing the use of toxic chemicals.

Catalytic converters are now an established part of any modern vehicle, but they depend on scarce and expensive resources. With the materials in a single unit now worth more than $1,000, recycling them is both cost-effective and environmentally sound.

Recycling MDF

Medium density fiberboard, or MDF, is one of the most widely used materials for furniture manufacture and is also popular in the construction industry. It’s relatively cheap, easy to manufacture into diverse shapes and its strength is much more predictable than solid timber. The problem is that MDF is a product of an age when efficient use of raw materials wasn’t a high priority, for producers or consumers, and that shows up when it comes to recycling. It’s not an easy material to reprocess; although the bulk of it is made up of wood particles it also contains significant amounts of adhesives, usually urea-based, and is often faced with various types of plastic. As a result of this most of it has traditionally been disposed of in landfills. It’s a bulky material, however, and while it usually deteriorates quite quickly it can take many years for the resin-impregnated wood to actually biodegrade. Carcinogens are also released in the process.

A lot of effort has gone into finding ways to recycle MDF, and several challenges have been identified. The main one is the adhesive which holds the product together; for many potential uses, including remanufacturing into new MDF, this must be removed. The easiest way to do this is by shredding the material and soaking it, to form a slurry, then heating it. It works, but uses large quantities of water and energy. UK company MDF Recovery Limited hope to make the process more efficient with a new ohmic heater they’ve developed specifically for MDF recycling; shredded MDF is soaked then an electric current is passed through it, resulting in rapid heating and breakdown with much less use of water. The recovered material is high enough grade to be manufactured into new MDF.

An alternative technology is the Micro Release process; this uses microwaves to break down MDF, and again it recovers wood fiber that can be remanufactured into fresh MDF. Both of these technologies are too new to judge how many times the material can be recycled before the fibers break down too much, but even a single reuse will add up to a significant cut in both landfill usage and wood consumption.

There are other options apart from reusing the wood particles for MDF. One of the simplest is just to shred the material then burn it, using the heat produced to generate energy for the recycling plant. Burning without energy recovery reduces the amount going to landfill but is wasteful, especially considering the potential uses for recovered particles. Another method now coming into use is to break down the MDF using the standard technique then compost it for agricultural use; this works best with MDF dust and is a good option for waste produced during the manufacture of MDF products. It does require a very high level of efficiency at removing the adhesive, to avoid the possibility of carcinogenic substances entering the food chain.

In 2004 over a million cubic meters of MDF was produced, and almost all of this is going to be disposed of at some point. Right now the majority goes to landfill, but with annual production continuing to increase this isn’t viable as a long-term solution. It’s vital that the new processing technologies are developed further and put into widespread commercial use; then perhaps MDF can be made as environmentally friendly as it is affordable and versatile.

Recycling Water

When we think of recycling it’s usually in terms of manufactured goods being converted back into raw materials for reuse. There are much wider applications, however, and in fact one of the largest and oldest recycling sectors doesn’t deal with manufactured goods at all. Instead it deals with a vital natural resource that’s plentifully available globally but, in a cruel twist of fate, often very scarce at a local level. That resource is water.

Water covers 71 percent of Earth’s surface, and the total volume on the planet is about 321 million cubic miles – an immense quantity. Unfortunately most of it is unusable as a resource. The main uses we put water to are drinking, agriculture and manufacturing, so we need liquid fresh water. Most of Earth’s water – 97.5 percent – is seawater, which is heavily loaded with salt and other minerals, and most of what’s left is frozen or otherwise inaccessible. Only 0.3 percent of the total is fresh surface water, and the demands of the growing population are putting this resource under huge strain. The problem is that most of the water we use is contaminated by that use. Recycling allows us to remove some or all of the contaminants and allow the water to be reused.

In practice all water is “recycled” through the natural water cycle, but deliberate recycling can hugely increase the available supplies. The aim is to allow water to be used more than once before it returns to the water cycle, and there are various ways this can be achieved. One of the simplest and oldest measures is the recovery of rainwater. Towns and cities have elaborate drainage systems to channel rainwater safely away, preventing damage to streets and buildings. This water picks up contaminants however, and is not safe to drink without considerable processing. However it can be used to irrigate fields or, after filtering, for many industrial uses.

Sewage is more of a challenge, as it contains large quantities of potentially hazardous waste. Since the 1920s sewage treatment plants have become increasingly sophisticated at allowing the water content to be reused. The most basic technique is to allow the solid waste to settle out, at which point the water can be released back into rivers; when it is extracted again downstream standard treatment methods can be used. Modern treatments usually process it further, either by chlorination or the use of bacterial cultures, to the point where it can be directly used for purposes other than drinking.

The latest technology can convert waste water directly back into extremely clean water suitable for drinking. Reverse osmosis, where permeable membranes are used to filter out any contamination, and ultraviolet disinfection are capable of turning heavily polluted waste into very high quality drinking water. An extreme example is the ECLSS system on board the International Space Station – this reprocesses all waste water, including urine, into safe potable water.

Many international relations experts predict that future wars could be caused by competition for water supplies. Already droughts can devastate agriculture and threaten millions of lives. If recycling can advance to the point where rivers can provide high quality water to every country they flow through this would go a long way to relieving these issues, so water should be one of the highest priorities for recycling.

Recycling Workers

There’s no serious dispute about the vital importance of recycling in saving valuable resources. Every informed person now understands that we can’t keep discarding materials after a single use, and that reducing the volume of waste sent to landfill is essential if we’re going to minimize pollution and environmental destruction. However that’s not to say that there isn’t a debate about the best way to recycle or a widespread belief that as it’s done right now the recycling industry has its own share of problems. One of the issues that need to be looked at is the people who actually work in the industry.

There’s a wide spectrum of technology used in modern recycling. Modern plasma jet plants are automated trailer units that can be easily set up and operated by a small crew. They’re largely automated and fitted with sophisticated systems to capture any dangerous chemicals emitted during the recycling process. That’s the high technology end of the spectrum though, and right now that sort of safeguard only applies to small plants in wealthier countries. A lot of recycling happens under very different conditions.

In many developing nations, and even middle-income countries like Brazil, most “recycling” is carried out by dump pickers who scavenge for potentially valuable material and sell what they find for scrap. That’s the other extreme from plasma jet units, but in between there are a lot of waste processing industries that place workers in unhealthy, and often extremely dangerous, situations. A large percentage of electrical and electronics scrap is still shipped to China for processing, where it’s sorted and broken up by hand. The processing technologies used create levels of pollution that can be extreme, and include lead and dioxins. Plastic waste is also shipped to China and other Asian nations for processing and again both pay and industrial safety standards can be extremely low.

One of the largest-scale recycling activities is shipbreaking. In the past this was often carried out in western yards, where ships would be moored alongside and stripped before being dry-docked and broken up by fairly mechanized workers. Now they’re more likely to be sold for deadweight and towed to India, Bangladesh or Turkey, where they’re simply beached then broken up by work gangs with hand-held tools. This is a polluting process that often results in oil and contaminated bilge water being released into the environment, and it’s also extremely dangerous for the workers. Deaths from badly maintained equipment, oil vapor explosions and collapsing superstructure or hulls are very common; pay for these workers is usually extremely low and protective clothing is minimal.

While many types of waste processing and sorting can’t be done economically in a high-wage economy like the USA, improved technology can change this. Much of the electronic scrap sent to China could be handled by domestic plasma arc plants if the capacity existed; it’s growing, but isn’t anywhere near large enough yet. Expanding these plants, and other advanced systems, won’t just reduce the risk to workers; it will save the energy used in transporting waste and in the often inefficient methods used to process it overseas. Finally it will create skilled jobs in the USA, so developing domestic capacity needs to be a priority in the waste industry.

About Downcycling

Recycling is becoming more popular as a way of both reducing the amount of waste we send to landfill and of conserving valuable or scarce resources. The second of these advantages could turn out to be the most important – many natural resources are limited, and when we’ve used them they’re gone forever. Recycling can make a huge difference to availability by making new products out of old ones instead of freshly extracted raw materials. Even renewable resources come at a price – land used for growing pulp trees might be more valuable for grazing livestock, if paper can be produced from recycled pulp instead.

It’s important to remember that recycling isn’t a magic bullet though. It can make a big impact, but one problem is that recycled materials often aren’t the same quality as the original waste was. This means that what’s recovered might not be suitable for making the same kinds of products, or might only be capable of recycling a limited number of times before it’s no longer usable. Improved technology is reducing this issue in some areas but it’s still very real. It even has a name – “downcycling”.

Continue reading “About Downcycling” »

Recycling Paper

Recycling PaperPaper is one of the biggest challenges to modern waste disposal. Paper makes up around 35 percent of domestic waste by weight and can cause significant problems in landfill. Huge quantities are used for disposable products such as newspapers and packaging and while the basic raw material – softwood – is renewable, significant amounts of energy and chemicals are used in the production process.  Most paper is produced using woods such as birch or aspen, but other fast growing trees such as poplar, ash and empress tree varieties are commonly used.

Tulip-poplar-TreeMany kinds of recycling are aimed at recovering scarce raw materials; electrical scrap, for example, contains valuable metals. Recycling plastics reduces the amount of oil used for producing new materials. That doesn’t really apply to paper because most new pulp is made from sustainable softwoods grown for the purpose. However converting raw wood to paper is an energy-intensive process, and while modern mills generate most of their power by burning scrap wood and bark this can create significant carbon emissions. Waste paper is usually printed, and as it decomposes in landfills the ink leaches out into the ground. This often causes heavy metal contamination of soil and even the water table.

Continue reading “Recycling Paper” »

Recycling Plastics

Plastics have revolutionized consumer goods. Cheap, versatile and durable, they’ve made whole classes of new products possible and reduced the price of others to the point where everyone can afford them. They’re a nightmare from a waste disposal point of view, though. Many types of plastic can take hundreds or even thousands of years to biodegrade. Huge quantities have ended up in landfill since the early 20th century and more is floating in the oceans, sometimes forming artificial islands of trash dozens of miles across. As well as the environmental damage of all this junk there’s the resources used to make it; most plastics are made from oil, a vital but finite resource. Efficient recycling of plastic waste is vital.

Because there are so many different plastics a wide range of recycling technologies are used to deal with them. Efficient sorting is key; different types often can’t be mixed to produce even low-grade material. Early systems worked with bulk waste that had been presorted by type but modern recycling plants use infrared technology to identify and automatically sort different varieties of plastic. These can then be processed appropriately.

One of the biggest challenges is plastic drinks bottles, made from polyethylene terephthalate (PET). Tens of millions of these are discarded every day in the USA, and unlike older glass bottles they can’t be reused. They can be processed into other products though.

First, bottles are sorted by color. Most of them are clear, making the process easier. Once sorted they’re washed and shredded into small flakes. The washing and shredding process removes scrap like labels and bottle tops, which are made of different materials. The clean, flaked PET is compressed into bales and sold for reuse.

Flaked PET can be heat-formed into a variety of products. It’s often used for packaging materials; clear PET waste can be made into clamshell or blister packs, used for packaging many small items. If it’s appropriately sterilized it can be made into new food containers; molten PET is blown into molds to produce new jars or bottles. It can also be injection molded for a variety of purposes.

One use that’s becoming increasingly popular is fabric manufacture. Heated PET flakes can be spun into fibers, which can then be woven into cloth. The result is a strong, hard-wearing fabric, although it’s usually too rough to be work next to the skin. It’s widely used for heavier duty items though, including bags, coats and hats. As recycling becomes more widespread environmentally friendly consumers are increasingly demanding these products.

Recycling plastics tends to be energy intensive, as heat is needed for most stages of the process, but it’s also something that needs to be done on a larger scale than it is now. Plastic in landfills can take a very long time to decompose, and as it does it releases toxins into the soil (and sometimes the water supply). Burial of plastics also adds up to a huge waste of valuable resources. Luckily improved recycling technology is making the process more economical and opening new uses for the recycled material.

Recycling & Landfills

Whenever a new recycling scheme or technology is announced one of its advantages is usually that it reduces the amount of waste going to landfill. In fact that’s one of the most important things new techniques can do – often it’s even more significant than recovering valuable metals or reducing the need for new raw materials. Landfill is a huge problem and the more it can be reduced the better.

A landfill site is one of the oldest methods of waste disposal, along with burning. It’s not much more than a huge version of the medieval village midden, but as the quantities of trash we produce increase the volume of waste going into huge pits in the ground, then being covered over and often landscaped, has skyrocketed. The problem is that a medieval village didn’t throw away much more than broken pottery, bones and old clothing; modern household garbage is filled with plastics, printed paper and old electronic devices.

Modern trash doesn’t simply biodegrade back into the food chain. Toxins in inks and old plastic are leached out by rain or groundwater and can contaminate aquifers. Electronic devices are particularly bad for this, as they contain many hazardous heavy metals. As organic waste rots it releases methane, a potent greenhouse gas – it’s up to a hundred times more damaging than carbon dioxide. Burning waste before burial doesn’t help either, as it simply releases more carbon and toxins into the atmosphere. Large accumulations of trash are a potential source of disease organisms that can then be spread by birds, insects and rodents. Even fire is a hazard – if a landfill catches fire it can burn underground for years, undermining the replaced soil above it and releasing pollutants.

There are multiple solutions to the problem of landfills. Some involve mitigating the issues caused by actual landfill sites, usually by managing drainage and improved capping of filled areas. These are only a partial solution, though. It’s far better to reduce the amount of waste that’s buried in the first place, which is where recycling comes in. Much of what gets landfilled can be reprocessed – paper, glass and many plastics. Organic wastes can be used to produce methane as a fuel. Electronics components can be dealt with by chemical or high-energy methods to recover their usable contents and reduce the rest to an inert, non-toxic residue that tales up far less space and is safe to bury.

Modern incinerator technology also allows much of the material that’s currently disposed of to be recovered. Metals and other minerals present in waste can be extracted from the smoke produced, while toxins and environmentally damaging chemicals are safely captured. Some of these methods are energy-intensive, which has to be balanced against the waste reduction, but others are capable of generating much of their own power from the incineration process.

Landfill is likely to be around for a while longer, although the Zero Waste movement’s ultimate goal is to see them phased out completely, but both consumer-led policies such as packaging reduction and improved waste handling and recycling can reduce the volume immensely. That’s good for the environment, good for natural resources and ultimately cheaper than burying so much potentially valuable material.