The regulations governing waste management in
Germany have led to a reduction of waste produced
in recent years, decoupling economic development and
waste production, in addition to a reduction of greenhouse
gas emissions associated with MSW management.
Currently, more than 60% of MSW is recovered; if energy
recovery processes are included, the figure rises to around
95% [3]. Moreover, the increase in waste recovery is
reflected in savings of fossil fuels such as oil, gas, and
coal. Electricity production in Germany in 2011 accounted
for 615 TWh. The share of renewable energies
was 20%, with 7.6% coming from wind power,
3.2% from hydropower, 3.1% from photovoltaic, and 6%
from different kinds of biomass, which includes a share
of 0.8% coming from energetic utilization of waste [4].
Electricity generation from the use of landfill gas in 2011
was less than 0.1% [5].
In most Latin American countries, the MSW management
system is in the best case limited to handling at
the source, collection, and disposal at landfills without
any pre-treatment [6]. Energy recovery from MSW in
Latin America is almost nonexistent. To date, the costs
of incineration are far too high for local governments to
consider it as an appropriate solid waste management
technology [6]. There have been a few experiences with
anaerobic digestion in Colombia and Costa Rica [7] but
mainly for the treatment of wastewater from agricultural
residues. There are some examples where mechanical
biological treatment (MBT) has been applied successfully
in Latin America, including experiences in Mexico,
Brazil, and Chile [8-10]. In most of these cases, the informal
waste pickers are the moving power in salvaging
recyclable materials.
The Metropolitan Region of Santiago de Chile (MRS)
is a typical Latin American megacity, showing population
growth over the last years as well as a rising standard
of living, associated with an increase of the gross
domestic product (GDP) from US$10,000 to US$14,000
per capita in about 10 years. As a consequence, the
amount of MSW produced also increased significantly.
The high population density and good infrastructure
allow for a very effective waste collection system,
whereby nearly 100% of the households have access to
collection services. Approximately 90% of the MSW
generated is deposited in sanitary landfills. Due to particular
characteristics of waste management in low- and
middle-income countries [11,12], most of the recycling
market is dominated by the informal waste economy,
constituted by primary collectors and middlemen [13].
Moreover, the urbanization process in MRS has also
increased its energy demand. Electricity supply for MRS
is highly dependent from electricity production outside
MRS [14], and only about 25% of its demand is produced
by power plants within the city. Electricity consumption
in 2010 was about 17 TWh; 50% of the
production in MRS came from different hydropower
plants, and the other half from a combined cycle gas
power station. Energy recovery from MSW in MRS from
captured landfill gas is so far only realized in the Central
Loma Los Colorados I station with an installed capacity
of 2 MW. Within the planned phase II, the capacity will
be extended to 14 MW, and an additional expansion to
reach 28 MW is planned for the year 2024 [15].
According to [16], each region should determine how
much it is able to spend in MSW management in order
to design its management system according to its economical
capacity considering at the same time the preservation
of human health, conservation of resources,
and the environment. Germany and Chile differ largely
in their GDP, and the German solid waste management
system is highly advanced compared with the Chilean
one.
Summarizing, although health and environmental problems
arising from inadequate MSW management are well known, Chile, as well as most Latin American countries,
has not set enough value into adequate MSW
management [17] nor has the development of services
related to waste management and its energy recovery
received sufficient attention. Against this background, it
seems to be a big challenge to find sustainable solutions
to handle the large amounts of MSW generated. This
article firstly presents the evaluation of different practices
of treatment, recovery, and disposal of MSW for
Santiago de Chile for three different scenarios for the
year 2030 based on the Integrative Sustainability Concept
of the Helmholtz Association. Based on this background,
the following research questions arise:
1. For the evaluation and comparison of different MSW
management systems, the Integrative Helmholtz
Sustainability Concept (IHSC) was applied. How can
this concept be contextualized to the field of MSW
management, what are the most relevant
sustainability indicators applicable to this field, and
what are their appropriate target values?
2. What are possible development paths of MSW
management in MRS for the next 20 years?
3. What technical options could improve the
sustainability (e.g., in terms of GHG emissions and
substitution of fossil fuels) of the MSW management
system?