Waste: LCM in the Waste Sector
Time: Wednesday, 31/Aug/2011: 2:00pm - 4:00pm
Session Chair: Shinichiro Nakamura
Session Chair: Juha K Kaila
Location: Room 3
1st floor


Policy instruments for a more sustainable waste management

Maria H Ljunggren Söderman1,5, Anna Björklund2, Ola Norrman Eriksson3, Tomas Forsfält4, Åsa Stenmarck5, Jan-Olov Sunwqvist5

1Chalmers University of Technology, Sweden; 2Royal Institute of Technology, Sweden; 3University of Gävle, Sweden; 4National Institute of Economic Research, Sweden; 5IVL Swedish Environmental Research Institute, Sweden

An on-going Swedish research program, Towards Sustainable Waste Management (TOSUWAMA) aims at assessing policy instruments that may contribute to a more sustainable waste management, shifting it towards the upper levels of the waste hierarchy - to waste prevention and material recovery. TOSUWAMA is an interdisciplinary program in which environmental, economic, cultural and social aspects of waste management are studied. Seeking a broad scope, economists, ethnologists, environmental psychologists, systems analysts and futurologists carry out the research in co-operation.

15 policy instruments have been chosen for final assessment in TOSUWAMA, ranging from administrative and fiscal instruments to information. Scenario analysis is used to deal with the uncertainties inherent in the long-term future: each instrument is assessed in four scenarios with different assumptions regarding the development of politics, economy, technological development, consumer behaviour etc. Assessments cover, with few exceptions, all generated waste flows in Sweden.

As basis for the economic and environmental assessment of instruments, we use a set of existing quantitative tools, which have been refined and combined for the purposes of the assessment:

  • the Environmental Medium term EConomic model (EMEC), a general equilibrium model of the Swedish economy
  • NatWaste, a systems engineering model of the Swedish waste-management system, and
  • SWEA, a life cycle assessment (LCA) tool for Swedish waste management.

The approach allows us to analyse the potential economic driving forces of policy instruments introduced on a macroeconomic level as well as instruments specifically directed towards the waste sector and, in addition, analyse the environmental effects.

The set of quantitative tools is used for assessing the following instruments: (1) Tax on raw materials, (2) Lower VAT on services, (3) Tax on incineration of waste from fossil fuels, (4) Ban on incineration of recyclable materials, (5) Including waste in green certificates for electricity production, (6) Weight-based collection fee, (7) Admail, yes please!, (8) Environmentally differentiated collection fee and (9) Developed collection systems.

We will present a selection of the assessment of policy instruments as well as future waste quantities based on the scenario analysis. We will also cover our experiences in combining LCA with other tools for analysing policy instruments for sustainability. In the final step of TOSUWAMA, our assessment will be integrated in an interdisciplinary synthesis, so that policy instruments for a more sustainable waste management can be suggested for the potential benefit of actual decision-making.

Life cycle assessment aspects of reuse products

Andreas Pertl, Gudrun Obersteiner, Stefan Salhofer

University of Natural Resources and Life Sciences, Austria

Preparation for re-use shall be the second priority of waste management in EU based on the waste hierarchy given by the directive 2008/98/EC on waste. New country specific programmes shall be implemented until 2014 to establish better re-use possibilities. These actions are assumed to raise the quantity of re-used products. Due to this reason also the environmental impact of re-used products will be of higher interest in the near future.

Life Cycle Assessment (LCA) is one of the most relevant methods for quantification of environmental impacts. The methodological basis of LCA is given in ISO 14040 taken over in the International Reference Life Cycle Data System (ILCD) Handbook. The ILCD Handbook provides approaches for allocation between first and second life. Nevertheless, when analysing a real life situation, the framework conditions may result in different allocation. This paper provides an analysis of two different scenarios for a re-use product to enter its second life. In the first case, the product is collected and sold by a junk dealer. Secondly, the product is delivered to a waste collection centre and fulfils the definition of waste, but will also be sold after a quality check without any further preparation.

In ongoing projects with focus on waste prevention LCA results of these two scenarios have to be compared. The consequences of the allocation rules for the waste-scenario (second case) are that all emissions from production have to be allocated to the first life of the product. This is different for the junk dealer-scenario (first case), where the product does not enter the waste regime and the emissions have to be allocated to the first and second life of the product. The paper analyses both scenarios quantitatively based on results of projects with industrial and public cooperation.

Further impacts on e.g. consumer information, product declaration or economic assessment of this issue will be discussed and presented.

LCA: A decision-making tool for recycling processes in textile industry

Sandrine Pesnel1, Anne Perwuelz1,2

1ENSAIT, France; 2Université Lille Nord de France, France

Nowadays, companies take more and more into account the environmental aspects because of legislation or ecological concern. In the textile industry, this environmental approach can be realized from the design of the product. For example, it is possible to produce an item made of organic cotton or to use a more eco-friendly dyeing process.

The introduction of recycling processes is also a way of eco-design. These processes can be realized at different levels of the life cycle: during the production or at the end of life of the textile product (recycling of post consumer waste). There are three kinds of recovering: the use as secondary raw material (the recycled material is re-used in the initial cycle), the use for another application in the textile sector, or also the use in a new line of business. So there are many possibilities and manufacturers must choose the most relevant solutions for their products. To make their decision, they can use the Life Cycle Assessment (LCA).

In this study, we focused on the environmental assessment of three recycling processes of textiles. We quantified, according to the LCA methodology, the impact of the following recycling processes on the life cycle of each product:

  • during the production stage, the re-use of short fibres resulting from the combing process in a carded spinning,
  • the chemical recycling of a polyester item at the end of life,
  • the mechanical recycling of a cotton fabric at the end of life.

Thus, the recycling processes are different because of their nature (chemical or mechanical processes) and the considered textiles (nature: cotton or polyester, and form: fibres or fabrics).

First, these studies quantify the specific environmental advantages to each recycling process. Then we can compare several processes and determine the most relevant one. For example, we can study the recycling of the matter and the energy recovery by incineration, and make a decision. The results of the LCA give also information about the possible ways of optimization of the recycling processes.

Biological recycling of bio-waste and compost utilization from a life cycle perspective

Francesco Razza1, Sandra Zaccheo1, Beatrice Cavanna2, Francesco Degli Innocenti1

1Novamont S.p.A., Italy; 2University of Tuscia, Italy

Only 1/3 of the bio-waste produced in Europe at household level is recycled (about 50 kg out of 160 kg, per capita/year). The rest ends up to landfill or incineration. Diversion from landfill is a very important challenge of our era and a priority for many local authorities. This study is a review of papers and documents addressing compost production and use and indicates that when bio-waste is properly recycled (trough composting or anaerobic digestion) and a high quality compost is produced, significant environmental benefits can be achieved.

Biological recycling reduces the amount of bio-waste delivered to landfilling or incineration; this, in turn, improves the environmental impact of waste management. On average recycling of bio-waste generates GHG emissions that range from -0.2 up to 0.04 ton CO2 eq/ton; fossil resources consumption ranges from -3.7 up to 0.4 GJ eq/ton (ranges depend on technology and compost utilisation).

In order to achieve good environmental performances, all actors of the "waste chain" must collaborate actively, starting from the citizens. Bio-waste contamination is one key aspect that depends on citizen’s behaviour. If bio-waste is contaminated (mainly by plastics, according to some studies) consequences are: (1) High amount of refuses produced by composting plants: up to 0.25 ton per ton bio-waste. This can be a significant burden from an environmental viewpoint. (2) Lower composting yields: 10% instead of 40% (average yield) (3) Lower compost quality which in turn can affect its commercial use on land or as peat substitution. Under some circumstances, the use of biodegradable plastics and packaging can help the collection of clean bio-waste, ready for biological recovery.

In conclusion, biological recycling of bio-waste into high quality compost and its application as soil conditioner provide valuable environmental benefits (e.g. fertilizers displacement, C-sink etc.) as pointed out by the LCA. However, many other positive features of compost application cannot be easily evaluated with the LCA methodology (e.g. increased organic matter content in soil, erosion reduction etc.). Such aspects are, in the long term, extremely important for sustainable development. Also to be noticed: if all the bio-waste produced in Europe were converted into high quality compost still this amount would be totally absorbed by the potential European market for soil conditioners.

Life cycle assessment of food waste management: A conceptual plan analysis

Slawomir W Hermanowicz1, Marc Francois Muller1,2, Domenec Jolis3, Natalie Sierra3

1University of California, United States of America; 2Swiss Federal Institute of Technology (EPFL), Switzerland; 3San Francisco Public Utilities Commission, United States of America

The City of San Francisco generates approximately 200 wet tons per day of source-separated organic solid waste that ends up a composting facility. San Francisco has established goals to reach a 100% landfill diversion by 2020 through increasing waste recycling including additional bins for household organic waste. This waste will be added to the commercial food waste to yield up to 400 wet tons/day thus exceeding the composting capacity. As an alternative, an additional anaerobic digester and biogas utilization facility in San Francisco is considered. To analyze potential impacts and benefits of the proposed expansion Life Cycle Assessment (LCA) methodology was used with the functional unit of processing 1 ton of organic waste and assumed life span of the project of 20 years.

The goal of the study is not to compare two solutions that would be built and implemented de novo but to compare a new not-yet-existing alternative with the currently used processes. The existing installations have been already built and operated. Their environmental impacts should be discounted and only the future impacts considered. We defined an “incremental” system as infrastructure and processes that are required to upgrade from the baseline to the alternative system including anaerobic digestion, biogas production and electricity generation, and also downstream effects on the composting yields, transportation effort and emissions.

LCA of the incremental system was carried out using Ecoindicator 99 methodology with 10 midpoint categories: carcinogens, respirable organics, respirable inorganics, climate change, radiation, ozone layer impact, ecotoxicity, acidification and eutrophication, land use, minerals, and fossil fuels. Impacts were aggregated into three endpoints: human health, ecosystem quality, and natural resources. The impacts are normalized and converted to eco-points (Pt). The overall single score for the incremental system of food waste digestion is negative (-13.7 Pt) indicating the combined environmental and human benefit of the proposed process compared with the existing alternative. A more detailed analysis of various impacts was obtained from midpoint characterization. Most of beneficial impacts are due to composting avoidance except for carcinogens, respirable organics and inorganics, and fossil fuels. For these four categories digester operation is the most important beneficial activity. Some midpoint categories are adversely impacted. In our case, the construction phase has strong detrimental impacts but digester operation and composting provide larger beneficial impacts over the lifetime.

Life cycle management for assessing systems of urban water management: Case studies and methodological gaps

Christian Remy, Boris Lesjean

Berlin Centre of Competence for Water, Germany

Triggered by climate change, local freshwater scarcity and rising public awareness, environmental aspects are becoming key decision criteria during the planning of urban water management projects. Among existing environmental impact assessment methods, LCA offers the most accepted and comprehensive tool to support decision makers with information on the environmental profile of new investments or upgrading of existing infrastructure. Due to the long amortisation (> 25a) and large capital needs within the water sector, it is crucial to optimize investments in terms of environmental benefits:

  • In the coming years, the implementation of the EU Water Framework Directive requires huge investments to upgrade existing infrastructure and decrease the impact of urban water management on surface waters. However, this comes at the expense of higher energy and resource demand, thus leading to a shift of environmental impacts.
  • Energy recovery from wastewater in terms of thermal of chemically-bound energy is of growing interest for the water sector. The identification of the most sustainable technologies and systematic approaches is crucial to optimize investments in this field and end up with efficient solutions beneficial for both water utilities and the public.

This presentation will give an overview of current LCA activities within the water sector by presenting several case studies from the Berlin area, namely in the fields of advanced wastewater treatment and sludge handling. The LCA framework is applied for a prospective comparison of technological options with the final goal of decision support for future investments. During the setup of these studies, methodological gaps are identified which require further improvement when applying LCA in the field of urban water management (e.g. definition of functional unit related to wastewater treatment, LCA impact assessment for wastewater treatment plant (WWTP) effluent, setup of inventories of WWTP processes reflecting seasonal dynamics). In all, the presentation should give an insight into the current status of applicability of LCA for the water sector and identify areas of further research needs.

LCA in wastewater treatment - applicability and limitations for constructed wetland systems: Using vertical Reed Bed Filters

Eva Risch, Catherine Boutin, Philippe Roux, Sylvie Gillot, Alain Héduit

Cemagref, France

Wetland ecosystems are known for their physical, chemical and biological microbial processes at play in pollutant breakdown and removal from water passing through these systems. Over the past decades in Europe, man-made ecosystems such as constructed wetland systems (CW) have been successfully harnessed to treat sewage and other pollutants in waste waters.

This work presents the application of LCA (Life Cycle Assessment) to a 2-stage “vertical Reed Bed Filter” (vRBF), designed following usual French guidelines. The LCA study is conducted for a vRBF plant designed for treating domestic sewage of a daily nominal load in BOD5 of 48kg/day.

The first LCA applicability challenge for CW systems is to get an equilibrated mass balance between wastewater inputs in Nitrogen, Phosphorus, Carbon and systems outputs. This consists in conducting a complex inventory of all air emissions from the vRBF treatment unit and of all substances retained in sludge, rhizomes, reeds (above-ground) and filter matrix. Then, to complete the LCA a further inventory is proposed following the end-of-life processes applied to the by-products of the vRBF system, e.g. spreading, composting or landfilling of sludge; onsite burning of reeds and rhizomes.

Indeed, most of the previous LCA studies on CW systems were focussed mainly on system construction and operation, choosing not to investigate in detail the end-of-life of these by-products.

The second LCA challenge to overcome in this work was to enable grounds for comparison in environmental efficiency of CW systems to conventional systems e.g. activated sludge (AS) technology. Although the choice of “functional unit” is critical in a comparative LCA study, it is of importance to include not only the resources used by each system but also to define effluent and sludge qualities since the systems’ performances are different.

LCA results of a vRBF system highlight the importance of eutrophication which can be explained by the poor removal efficiency of organic N and phosphates. Except for eutrophication, in the systems comparison the vRBF has the lowest scores on almost all impact categories. Finally, the article analyses the applicability and limitations of LCA for wastewater treatment comparison in terms of water quality. Research perspectives to improve the method and enrich current databases are finally drawn from this study.

A comparative life cycle assessment of a wastewater treatment technology considering two inflow scales

Leonor Patricia Güereca Hernández1, Adba Musharrafie2, Edgar Martínez2, Alejandro Padilla1, Juan Manuel Morgan Sagastume1, Noyola Robles Adalberto1

1Universidad Nacional Autonoma de Mexico, Mexico; 2Tecnológico de Monterrey, Mexico

A Life Cycle Assessment (LCA) is carried out for two wastewater treatment plants of activated sludge technology with different scales of inflow: 10.5 l/s (small WWTP) and 1500 l/s (big WWTP), in order to determine if several small WWTP are environmentally preferably to one big WWTP to treat an equivalent inflow. The functional unit is the quantity of inflow treated by the big WWTP during their lifetime, which is considered as 20 years. For both systems the energy consume, raw material, emissions to air, solid wastes and water discharges were quantified for each one of the life cycle stages: equipment fabrication, construction and operation of the plants. The impacts categories analyzed were air acidification, aquatic toxicity, depletion of abiotic resources, depletion of stratospheric ozone, eutrophication, global warming potential, human toxicity, photo-oxidants formation and terrestrial toxicity with the CML 2000 methodology. The results of this work suggest that the installation of one big WWTP is better in environmental terms that several small WWTP for all the impact categories analyzed. The operation is the stage with worst environmental performance due, principally, to the use of electricity by the aireation system, which coincide with the reported in literature. In order to extrapolate the results obtained to other locations, special attention should be paid to wastewater transport, electricity mix and sludge management. This study is part of a research project in which the most representative wastewater treatment technologies for Latin America are being evaluating to propose the most appropriate technologies for the region, considering technical, economical, environmental and social aspects.