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Empowering Our Communities To Redesign

Mechanical Biological Treatment (MBT) & Zero Waste

Many cities have built Mechanical Biological Treatment Facilities (MBT) during the last decade with the aim of reducing the waste to be finally dumped or burnt. The results depend on every case but it is clear that MBT alone is not the sollution for anything. However it can play a role in transitional strategies to reduce residual waste without having to depend on more expensive undesirable options such as incineration. A well-designed ideal Zero Waste strategy shouldn’t need MBT.

What are MBTs?

MBT covers a wide range of activities and technologies to deal with residual waste –i.e. waste that hasn’t been separated for recycling or composting-. As the name explains it is composed of a mechanical part -in which waste is mechanically separated to recover recyclables- and a biological part –to either compost or digest the organic fraction-.

There are three main outputs from an MBT plant are; recyclables –such as PET plastic that can be sent for recycling-, low quality soil –the biologically stabilised part is used for land reclamation, almost never for agriculture- and RDF, Refuse Derived Fuel, which is a mix of materials with a homogeneus calorific value to burn in incinerators or in some cement kilns.

MBT became popular with the entry into force of the Landfill Directive which obliged member states to reduce the biodegradable waste going to landfill. MBT has the capacity to reduce the volume and methane emissions from waste, plus since it is modular it allows some flexibility and is cheaper and faster to build than any other big scale centralised options.

The draw-backs of MBT are that the bad quality of the compost they produce; almost always too polluted to be applied as soil improver. As a consequence, some authorities see MBT as a way to meet recycling rates without actually recycling and the production of RDF aimed at being burnt in incinerators and cement kilns.

MBT in Europe

MBT have been used with different success in Europe. For instance, in Germany they have been in use for more than 10 years and albeit having obtained some good results, the bigger the plant the more malodours and bacteria for the neighbourhood. The experience has been proven that MBT is not necessary when biowaste collection works well and there is high quality separate collection of other waste-streams combined with a good product policy promoting prevention of chlorine/PVC, heavy metals and flame retardants.

In Barcelona, Spain, MBT facilities were called ecoparcs and have been in operation since 10 years. Although they have managed to considerably reduce the amount of waste sent to landfills and are recovering materials for recycling it is a fact that no good compost has come out of these facilities whilst their production of RDF has increased. In fact, after all the expensive investments in MBT the city of Barcelona ended up implementing separate collection of organics (2010) after realising that the only way to get good compost is with input coming from biowaste source separation.

MBT and Zero Waste

A Zero Waste strategy means that waste should be prevented and source separation should be maximised. If all the products in the market would be recyclable and properly separately collected there will be no waste and hence no need for MBT. If MBT has a place in a Zero Waste strategy is only when dealing with the current 20-30% of total municipal solid waste that can’t be source separated and collected. In these cases MBT can be a temporary solution but always keeping in mind the goal of continuing minimising the residual waste.

In fact, the real name for MBT in a Zero Waste strategy would be a combination of a Material Recovery Center together with a Zero Waste Research Center. In these facilties the recoverable materials are recovered and the few residuals left are stabilised so that they can be safely landfilled after they go through the Zero Waste Research Center which analyses the defects in design in order to work upstream to make them recyclable in the future.

One of the pillars of Zero Waste is source separation of organics –the only way to obtain clean high-quality compost- and experience proves that this can’t be replaced by MBT.

Unfortunately there is no European legislation asking for separate collection of organics and hence European waste policy continues to lack a driver that would probably make MBT unnecessary. However, a growing number of Zero Waste municipalities are separately collecting biowaste and other waste fractions and already achieve high recovery rates combined with job creation.

The more separation at source the less separation is needed at the end (MBT) and the less disposal facilities (landfills and incinerators) are needed!

Meeting of Zero Waste municipalities in Capannori, Italy, 7-8-9th October 2011

More and more European municipalities are adopting the Zero Waste goal. This is why a meeting will be held in the craddle of Zero Waste in Italy, Capannori, to organise the coordination -national and international- of the Zero Waste Communities.

The meeting will take place from the 7th to 9th October and will include the presentation of the books Zero Rifiuti, by Marinella Correggia, and Il Libro dello Spreco in Italia, by Luca Falasconi-Andrea Segré, the screening of the movie Zero Waste, by Victor Ibanez.

Representatives from more than 50 italian municipalities will be present in the meeting. With representatives from the Zero Waste program of the city of San Francisco, US, from the Spanish municipalities of Hernani, Basque Country, and El Papiol, Catalonia, and also from Sweden and England .

Finally there will be a meeting of the Zero Waste Research Center, which was established in Capannori a year ago, in which innovative ideas to change product design (such as coffee capsules, shoes, packaging, diapers…) will be discussed.

To see the program click here.

New EU’s Resource Efficiency roadmap points in the Zero Waste direction

The EU has an ambiguous policy when it comes to Zero Waste; on one hand it promotes recycling and separate collection and on the other hand it rewards energy generation from burning waste more than it rewards energy savings from prevention. In a former post we have highlighted these contradictions of EU’s waste policies. But the Resource Efficiency Roadmap published on the 20th September 2011 hints new ambitions for the EU to move towards a Zero Waste Europe.

The roadmap has a strong push towards “residual waste close to zero”  -although there is no definition of residual waste at EU level-  and it underlines that “incineration with energy recovery should be limited to non recyclable materials, landfilling is virtually eliminated and high recycling is ensured”. A portion of the text reads:

“Milestone: By 2020, waste is managed as a resource. Waste generated per capita is in absolute decline. Recycling and re-use of waste are economically attractive options for public and private actors due to widespread separate collection and the development of functional markets for secondary raw materials. More materials, including materials having a significant impact on the environment and critical raw materials, are recycled. Waste legislation is fully implemented. Illegal shipments of waste have been eradicated. Energy recovery is limited to non recyclable materials, landfilling is virtually eliminated and high quality recycling is ensured.
The Commission will: …
• Review existing prevention, re-use, recycling, recovery and landfill diversion targets to move towards an economy based on re-use and recycling, with residual waste close to zero (in 2014);
• Ensure that public funding from the EU budget gives priority to activities higher up the waste hierarchy as defined in the Waste Framework Directive (e.g. priority to recycling plants over waste disposal) (in 2012/2013);”

Full text of the Resource Efficiency Roadmap here

As explained in a previous post recycling is not enough and we need to move towards a Zero Waste economy, i.e. we have to reduce our resource use whilst making sure everything produced is recyclable and recycled. The EU is now starting to do the shift from being a Recycling Society to a Zero Waste Society. However, right now the Resource Efficiency Roadmap are just a pile of inspiring statements and visions, that need to be put into action. In order to do so lots of policy changes -such as increasing recycling targets or mandating separate collection of organics-  will have to take place and it is then when we’ll see how serious we are about a Zero Waste future.


Business & Zero Waste

Zero Waste is one of the pillars of sustainability. It is impossible to be sustainable as long as what we discard cannot be the resource of another process without endangering health or the environment. This is why Zero Waste concept is good for both people –less pollution- and the business sector –less innefficiency and costs-.
The book “New Standards for Long Term Business Survival” from J. Scott explains why waste doesn’t make any sense from a business perspective. Using several examples and reviewing the recent history of the relation between companies and waste, Scott explains how the business world has changed and is continuing to change in the direction of Zero Waste.


It explains the great work of Walter Stahel regarding the “closed-loop economy” and the two ways to achieve it; either by reusing, repairing or remanufacturing products and their materials, which facilitates job creation and decreases virgin material usage (by re-using molecules) or by optimizing the profitability of products by converting them into a service so as to keep the product’s materials in the hands of the manufacturer in order to lower raw material and production costs. Safechem, Michelin or Interface are succesful example of this second option of selling a service instead of a commodity (selling square meters of cleaning, the distance a tire can travel or the meters of carpet-covered floors).

This book and other from J.Scott can be downloaded for free from our ZW library.

From this book we extract 6 Key Teaching and Learning Points
1- Waste elimination and resource maximization are two sides of the same coin. One cannot occur without the other.
2- Waste elimination is an on-going process. There is no finish line.
3- Waste creation does not equate with freedom nor is it a basic human right: the world is interconnected and has limited resources –and waste impedes the well-being and security of others.
4- Waste is a financial burden to businesses, customers, and local, national and international communities.
5- Spending money on lawyers and lobbyists to fight against higher efficiency standards or for the right to create waste is counterproductive, self-defeating, costly and pointless.
6- Taxing waste has the capacity to serve two purposes: (1) the money collected can fund and support infrastructure building, and, (2) businesses and industries would be encouraged to be less wasteful.