Waste Processing

Landfill
Landfill is the end of a one-way road for our habit of buying, using, and discarding. The by-product of consumption, our dirty little secret? Massive lost opportunities lay in the heart of a landfill.

Landfill, as it suggests, is direct burial of waste. It should be viewed as a last resort. Increasing costs for sending waste to landfill is an effective deterrent to this previously popular disposal method. Costs can be through landfill taxes imposed by government, or through weighbill fees charged by the facility operator.

Buried organic waste when it ‘rots’ creates methane, which is a potent greenhouse gas between 25 and 75 more so than CO2. Therefore you also don’t want to send your organic waste to landfill. Some landfill sites do ‘harvest’ methane, however there is controversy over the effectiveness of this method.

Rubbish which is toxic should also not be sent to landfill as there is a high potential of the toxic substances leaching into ground water and eventually making their way to waterways.

The problem with landfill:

  • Tonnes of valuable recyclable material sits buried while new resources are extracted from the ground or created in factories to replace what we have discarded.
  • Tonnes of biodegradable waste lays rotting, sending up methane, when it could have become fertilizer if processed through a composting facility.
  • Landfill holds the potential for the escape of leachates that cause soil and ground-water pollution.
  • In some areas we are simply running out of landfill space.

Landfill Gas
Landfill owners, waste treatment companies and the like are rolling out investment–heavy technology and infrastructure to capture the energy potential of methane generation from landfill – Energy from Waste (EfW). In the United States there are EfW landfill gas harvesting landfill sites in every state. But, and this is a BUT-with-a-capital B, having these EfW sites can also encourage guilt free trashing and destruction of resources.

A Note on Methane:
Methane is generally accepted to be between 23 and 27 times more potent a greenhouse gas than CO2, but there is some debate over this figure. In order to come up with a standard set of measures to place the various greenhouse gases on an even keel, CO2 is used as the base, with a 100-year life span. But methane’s average lifespan is just 12 years. When you consider the actual short-term potency of methane, it’s far more than 23 times that of CO2, possibly really 75 times as powerful.  We’re dealing with a very effective greenhouse gas here, and every time we throw something compostable into the bin to make its way to landfill, we’re contributing to the problem in quite a big way.

Waste to Energy
Waste to Energy (W2E) processing is gaining popularity and the options include incineration and gasification.

Incineration: Energy produced from the incineration process is converted into electricity, often through the heat boiling water into steam to drive electricity turbines. In order to maximise effectiveness of this process, the heat should be captured and redistributed to local buildings. Thus incineration based W2E facilities are best in cold climates where heat generated can be used. Other problems with incineration-based W2E are pollutants released into the atmosphere as waste is burnt, along with remaining pollutants in the solid matter remaining.

Pyrolysis/Gasification: Another option for W2E are also thermal technologies similar to incineration, however this is done in the absence of oxygen and under high pressure. The result is gas and liquid which can be combusted to fuel electricity generators, plus solid matter (charcoal).

The end process of the incineration or gasification is a gas which is then combusted, creating CO2 emissions.  Prevent carbon from entering the atmosphere as a greenhouse emissions by not sending waste to be incinerate, but rather through sending it back into the system as a valuable resource: compost your biodegradable waste, don’t turn it to energy; recycle your recyclable waste, don’t turn it to energy. Leave renewable energy supply to solar, wind and other new truly zero emissions sources.

The problem with waste to energy:

  • If compostables and recyclables end up in an incinerator to be burnt, the CO2 emissions as a result go out at a rate higher than a coal fuelled power station.[1]
  • Having an option for waste disposal such as energy generation from incineration, can encourage guilt free single use and a throw away mentality. Does nothing to encourage frugal consumption.
  • Discourages recyclable and compostable material from being used for its highest purpose.
  • If timber and paper products are lost from the recycling process to incineration, new virgin materials now need to enter the system.

Caveat: It must be noted that incinerator supporters see the burning of food waste, green waste, paper and wood as carbon neutral as it’s considered part of the natural carbon cycle, and therefore they don’t include emissions from these sources in their data. But because there is a much higher purpose for recyclables and compostables, we choose not to ignore CO2 that comes out of an incinerator’s smoke stack.

Mechanical Biological Treatment
Where it is impossible to separate out biodegradable waste from other general or recyclable waste, mechanical biological treatment is an option. This is where the non-biodegradable materials are sorted and separated from the biodegradable materials. Non-biodegradable materials are recycled or sent for waste to energy and the biodegradable materials are then sent on for composting or anaerobic digestion.

Material Recovery Facility/Recycling
In many countries an automated or semi-automated facility exists to process recycling. All the rubbish is sent in one end and each type of recyclable material is sent shooting off in a different direction, contaminants pulled out each step along the way. The end result is separate types of recycling – glass, metal, paper, plastic, etc – which are then sent onwards for recycling processing. You need to determine what types of plastics and other materials your MRF can accept, in what condition and whether segregation is required/preferrable.

Some MRFs are run by the local municipality, others are private concerns and the technology and investment in infrastructure varies, which impacts on what can and can’t be recycled. Some will take plastic drink bottles, but not milk bottles. Only some can take Tetrapak (cardboard cartons lined with aluminium).

MRFS are often set up to take residential waste or commercial waste. Event waste sits in between these two types of waste, so ensuring your event waste is delivered to the MRF in the best form will impact on the effectiveness of segregation and onward recycling.

Manual Handling
In countries where the cost of human labour is low, people work either as employees or as independent waste pickers, carving out a living through manually sorting and selling-on recyclable materials. Recyclable materials go on a terrific journey from the streets, through the slums, to micro-processing workshops and onwards to larger processing facilities. In countries where millions live off the recycling industry it would be inappropriate to introduce automated processing. Alternatively, those with events in such countries should team up with NGOs who work with waste pickers to ensure fair prices are paid for recyclable materials and to help them with equipment, healthcare, food and education for their children. You may need to work hard to find the most appropriate way to dispose of it, or alternatively you may have a race on your hands as people compete to get the valuable resource that is your recycling.

Waste Cooking Oil
Many events sell and serve food and as a result may have waste cooking oil to dispose of. Collection facilities exist in most regions as this waste product is a valuable resource to be used for making biofuels. In India it is also valuable as lamp oil for temples.

Composting
Collecting biodegradable waste separately and sending it to the closest processing facility, whether an in-vessel composting site, windrow setup or even composting on the land your event is held, is an important step to reducing the landfill footprint and consequential production of methane emissions. Commercial facilities are likely available.

Anaerobic Digestion
Anaerobic digestion (AD) is used all over the world, particularly on a small scale in agriculture in nations such as India and Thailand, and is also used widely in Europe. AD is composting biodegradable material in the absence of oxygen. The result is biogas (a mixture of methane & CO2) used to generate electricity and heat, and digestate the solids/liquids left at the end of the decomposition process.

Hazardous Waste
At events this can include fluorescent light tubes (containing mercury), batteries (lead, sulphuric acid, cadmium), chemical and solvents, medical and first aid waste, sharps bins, paint, treated timber such as MDF. You need to discuss with your waste contractor and local processing facilities the appropriate way to segregate, transport and dispose of this waste.There is likely environment agency regulations which you must adhere to.

Electronic Waste (WEEE)
Once electronic equipment is no longer repairable, to be responsibly disposed of, it needs to enter the appropriate electronic waste recycling route. Local municipalities will most likely provide points to dispose of electronic waste. There may also be regulations in place which you must adhere to. Some producers may also have take-back schemes. Electronic waste is stripped back to its component parts and various materials extracted for recycling.

Textile Recycling
Textile recycling is a difficult and time consuming process due to the huge range and combination of materials possible. Textiles can stripped to component parts and re-used, turned into rags, fibre can be reclaimed for use in yarns, materials can be shredded and used as filler for cushions and furniture. Textiles must be separated from other waste and kept clean in order to be processed. Make sure you check with your waste management company and processing facilities to see if they can take it and in what condition. Alternatively look for local textile reclamation programs and send your used textiles out locally. Reuse centres and secondhand stores will also be interested.

 

Re-Use Centres
Facilities such as Reverse Garbage in Sydney, or tip-shops at the local dump will take salvageable items.  You just need to make sure you don’t bury salvageable stuff under rubbish in a skip. They won’t pick through it, you need to.

 

Waste Impact of Purchasing
Of incredible importance is the understanding waste occurs at every step along the one-way road of resource consumption, production, use and disposal. By reducing the amount we use or responsibly sourcing the products we sell and consume at events, we will in turn be reducing waste back up the supply chain. For every tonne of end-of-life-cycle waste, approximately 71 tonnes of waste is produced during the original product’s journey from raw material to manufacturing, distribution and sale.[1]


[1] Ciplat, Lombardi, Platt, June 2008. ‘Stop Trashing the Climate, p. 4.  www.stoptrashingtheclimate.org