I hear people say: “That’s not possible”
So I think: “Let’s take a look at it.”

Prof. Roland Pomberger and his team at the University of Leoben are researching the potential of waste management technology. We spoke to him about the trends in the waste management sector.


Professor Pomberger, what do you understand by the term zero waste?

I think it’s a great term. But you need to put it in the right context, as believing that the world will one day generate no more waste is an illusion. I define zero waste as “no wastage and instead doing something useful with it.” If we therefore understand zero waste to mean that no more waste enters landfill or disposal, and that all waste is recycled instead, this is a goal worth striving for. Pursuing this interpretation is a good approach.

In your opinion is waste unavoidable?

Indeed. There are three main principles in the waste industry. Firstly: “Every product becomes waste. It’s simply a question of when.” People who work in the waste industry do not need to worry. Their jobs are very secure against crises. Secondly: “Everything that can be contained in waste is in fact in it.” Each time waste is sorted, it will undoubtedly contain something that doesn’t belong there. Companies need to be prepared for this. And thirdly: “Waste disposal is carried out depending on what is legally permitted and not necessarily what is most sustainable.”

There are always topics relating to waste management that are of interest to companies in the industry, and for which we can provide support through research.

Prof. Roland Pomberger

Two drivers of waste management

With the last principle, do you mean that recycling is not worthwhile without quotas?

No, there are two drivers in the waste industry: environmental protection and the value of raw materials. The latter is regulated by the market price. Nobody needs a recycling quota for gold waste. The same is also true of scrap. A quota is always required wherever recycling doesn’t happen despite demand in the market
and therefore a minimum standard needs to be prescribed. This means that 65 % of municipal waste must be recycled in the future. If this standard is not applied, then it will not happen. With most waste – and this is a really sad fact – the value of raw materials doesn’t cover the entire costs that are required upstream and downstream of the waste treatment process. Collection, sorting, and recycling are beneficial, but economically speaking they often don’t cover the costs involved. However, we need to do it because the environmental benefit to society is very high and therefore essential. It is difficult to monetize. This is why we need regulations such as taxes, specifications, quotas, and deposit systems. But on its own, this wouldn’t work.


Keyword: Deposit system what is your take on the following hypothesis: ‘modern processing technology is so good that the model for separate waste collection is outdated’?

That is wishful thinking. It is not how the separation of mixed waste works. First of all, the materials in the waste do not stay the same as they were when they were thrown away. They affect each other. For instance, take plastic food wrap which ferments in biowaste. It becomes soiled and its molecular structure may even be affected. Whatever gets thrown into the mixed waste container is not
the same as what comes out later. Secondly, if the waste has been separated
beforehand, a company operating a plant will achieve greater output with higher purity. The explanation is quite simple: a plant is a one-stage process. With prior separate collection, we have a two-stage process. There are pre-sorted fractions that are sorted once again. This is better of course. In our view, the people who hold an item of waste in their hand and decide where to dispose of it, represent the most valuable link in our sorting process.

More substitute fuels

Where does the energy recovery take place? Will recycling result in a shortage of substitute fuel?

One thing I often hear is: “We’ll recycle in the future, as eventually incineration will no longer be needed.” That’s incorrect. There will certainly be less of the classic waste incineration where non-separated waste enters the furnace directly following collection. But we’ll even see more industrial utilization – whereby processed materials are used as a fuel, replacing fossil fuels. Thermal utilization and recycling are not opposites. On the contrary: increased recycling leads to more substitute fuels that end up in industrial incineration. Recycling and high-quality, thermal industrial utilization form a symbiosis. In Austria, 80 % of the energy required by the cement industry, for example, is covered by processed waste. It makes absolute sense to substitute fossil fuels with waste.


Nobody needs a recycling quota for gold waste.

Prof. Roland Pomberger

Where do you see further economic potential for the waste industry?

There’s a great deal of optimization potential for controls within and around plant. Sensor-based sorting is where I see the greatest potential and the issue of how to integrate and exploit automatic sorters in existing plant or plant in general. This goes hand in hand with sensor-based monitoring. Plant operators should know more about what is happening in their plant. For instance, whether the belt occupancy is correct, as the machines don’t adjust themselves to the material, but instead are adjusted externally. Studies have shown that many sorting plants only operate in the optimal range for 30 percent of the time. The rest of the time, they are either running empty, or with too much or too little material.

By homogenizing the material flow alone, a lot more could be achieved in this area. As part of one project, for example, we have measured the performance of a mobile machine and informed the operator that – by readjusting here and there – they can increase the machine’s performance by up to ten percent and improve quality levels.


Whatever gets thrown into the mixed waste container is not the same as what comes out later.

Prof. Roland Pomberger

Let’s take a look beyond the borders of europe: where do you see the greatest challenges in emerging countries on their journey to a regulated waste industry?

Each country has its own special challenges. The waste industry must be developed and adapted to the country. In doing so, there is one error that must not be committed, in my opinion: reducing the waste industry to purely technological issues. It isn’t as simple as that. Waste is also a matter of wealth. Countries need to be able to afford high-quality waste management. Therefore, we must always look at how much money is available in a country for waste management activities. Here in Austria, this stands at EUR 200 per inhabitant per year, but in Dhaka, the capital of Bangladesh, the amount is only EUR 2. If little money is available, then very little can be done.
But in emerging economies, small mobile facilities can be a good start in rural regions, in order to develop a decentralized waste industry. I see an opportunity and a great need here.

What do you think of the statement: ‘It makes no sense to want an undeveloped waste industry to transform into a well-established one in one step’?

I fully support this statement, which is backed up by many examples. It must be done step by step. Setting up a highly automated plastic sorting plant in a country that does not even have decent landfill will not work. It’s not possible to copy other countries and say: “It works for us, so it will work for you.” In my view, this approach is doomed to failure.