Insinkerator HC3300CH, 200, 100, 56, 66NEW Handbook

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Not Going to Waste

The role of food waste disposers as part of a total waste management solution

Introduction

Waste generation, Population & GVA, 1997-2012

INDEX WASTE GENERATED POPULATION GVA

300

250

200

150

100

50

0

1997-98 1998-99 1999-00 2000-01 2001-02 2002-03 2003-04 2004-05 2005-06 2006-07 2007-08 2008-09 2009-10 2010-11 2011-12

In the face of a rapidly growing population, nding an

appropriate method of dealing with household waste
continues to be a matter of heightened importance. Food
waste accounts for more than 30% of the total rubbish
in household garbage bins therefore suitable treatment

reduce their dependency on unpredictable price uctuations

of fuels. From a waste management and environmental
impact perspective, state and local governments are
committed to the issue of climate change and proving

measures to avoid methane emissions from landlls.

options for this organic component could help alleviate a
global waste problem.

Therefore alternative methods of food disposal would

potentially impact signicantly. Food waste disposers while

At a global level countries are keen to reduce their reliance
on fossil fuels and provide alternatives to wood fuel. At a
national level, residents, commerce and industries want to

serving a practical function in terms of household hygiene
and convenience have the potential to provide a number of

benets on a far broader scale.

What happens to food that is thrown away?

Australia is heavily dependent on landll as a means of

waste management. In fact, the majority of non-recycled

waste will end up in landll sites.

Estimates suggest each household produces close to 1.5
tonnes of waste each year. And nearly half (47% in 2009-

10) of all household waste is organic – namely food scraps.

One concern is that waste generation has been growing
at a disproportionate rate. Between 1997 and 2012 – when
overall population growth was 22% – the volume of waste
production jumped by 145%.

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The problem here is that landlls are effectively an ‘out of sight,

out of mind’ solution. They potentially have a detrimental impact
on surrounding air, water and land quality. There are, however,
better ways of managing wastes, especially food waste.

A by-product of anaerobic organic waste decomposition is

2

a gas which consists of around 50% methane. Methane in
the atmosphere is a strong contributor to climate change,
being over 20 times more potent in this regard than carbon
dioxide.

4

harnessed as a valuable renewable energy source. Using
a food waste disposer can facilitate just that without the

social dis-amenity associated with landlling.

1

However, if captured and ‘cleaned’, it can be

Source: Australian Bureau of Statistics Waste Generation, Population & GVA 1997-2012

Food waste and renewable energy

Instead of piling food waste into bins and, ultimately, landll,

food waste disposers can be used to grind food scraps
which is then sent via the sewerage system to a wastewater
treatment plant. Here appropriate facilities use a process
called ‘anaerobic digestion’, to convert waste to biogas.
Anaerobic digestion is a collection of processes by which
microorganisms break down biodegradable material such as
organic food waste in the absence of oxygen.

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The anaerobic

digestion process produces a biogas methane.

When cleaned, the methane fraction can be stored,
pressurised and used to generate on-site power and heat.
The power can be used on-site with surplus fed into the
electricity grid. Methane can also be upgraded to natural
gas-quality biomethane, and a by-product of the digestion
process is a nutrient-rich digestate which can be used as
fertiliser

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for areas such as golf courses, playing elds

and pasture lands.

5