Ready for new challenges

At the Institute of Waste Management and Circularity (ABF-BOKU) a motivated team under the leadership of Professor Marion Huber-Humer teaches and researches on innovative concepts and processes for sustainable waste management and a circular economy.


Climate change, resource scarcity, food security: The questions of the future call for answers. With over ten thousand students, the University of Natural Resources and Life Sciences in Vienna (Universität für Bodenkultur Wien, or BOKU) is an important educational institution that provides the tools to address the varied future global challenges and tasks.


Opportunity: Professor Huber-Humer, what are the areas of expertise of your Institute?

Professor Marion Huber-Humer: According to the EU Waste Directive, waste avoidance and re-use have the highest priority. They are important focal points of our research at the institute. We concentrate particularly on the question of how to reduce food wastage. That is something close to our heart. Circle-oriented waste management is another important area. We work on the analysis and optimization of collection systems and usage options. In addition, landfilling remains an indispensable element in waste management. So we take part in technology research and development for the low-emissions, environment-friendly, monitored storage of residues.  We use innovative measurement methods and continue to further develop them. To name one example, using open-path laser measurement devices and dispersion modelling we do research on the quantification of greenhouse methane emissions from waste treatment facilities and landfills.


Opportunity: Let’s briefly look at the topic of food. The current crises are causing interruptions in supply chains, and along with sharply higher prices this is bringing food into the focus of public attention. Is wastage really an important issue?

Professor Marion Huber-Humer: Absolutely. I don’t think very many people are aware of this. The effects of this waste on the climate and the environment are enormous and unnecessary. You know, for nearly twenty years food waste has been an important research field at our institute, and our results show that solutions are needed for private households in particular. Much more food is wasted at the household level than at any other point in the value-creation chain. So we see it as our task to identify solutions, in addition to developing methods and doing comprehensive data capture. We make very specific action recommendations for producers, retailers and consumers. Sensitizing is particularly important for the latter group. We also work closely with schools and training facilities in the tourism industry, and take part in various projects with practical focus.

“In Austria, each year about a million tonnes of edible foodstuffs end up in the bin.”

Mario Huber-Humer

Opportunity: Thank you, Professor Huber-Humer. Now a question for your colleague, the engineer Erwin Binner. Mr. Binner, even with the most careful use of food, leftovers remain. As organic waste they can be made useful, for example by composting. You’ve made an important contribution to the very good reputation the Austrian compost industry enjoys today. What would you say were the milestones in recent years?

Erwin Binner: Like in many other countries, Austria started composting waste a few decades ago. It very quickly became clear that waste compost sometimes contained high amounts of contaminants. So, in the late eighties Austrian Standard S2022 laid down the first quality criteria for waste compost. Parallel with that, standards for testing methods and application guidelines came into being. In order to further improve compost quality, trials were done on the separate collection of biodegradable waste from households, for example in Klosterneuburg, Graz and Vienna.

The first major progress came in 1992 with the regulation on the separate collection of organic waste, which made waste separation mandatory from 1995. At almost the same time, in 1993, Austrian Standard S2200 laid down the quality criteria for composts from organic waste. Along with its ancillary standards, it defined much stricter limit values than its predecessor, Austrian Standard S2022.

The Austrian Compost Regulation in 2001 was the next milestone. With it, Austria became the first country in Europe to legislate “the end of waste.” Compost made compliant with this regulation is no longer considered waste, but instead takes on the status of a product! The regulation largely incorporated the testing parameters of S2200 and the test methods of S2023, with the limit values adjusted where necessary. Since then, in Austria we make compost products in quality class A+ for use in organic agriculture, and quality class A for use in conventional agriculture. At ABF-BOKU we provided scientific support for these processes, primarily by developing methods to determine the quality and positive properties of composts. These include the maturity and stability of the organic compost substance. We also developed a model for determining the humic content of composts. The humic content is an important quality criterion for composts, and this measurement model is based on infrared spectroscopy. Another research area we’re focusing on right now is microplastic contamination in composts.

“Biogenic waste is an important fraction in meeting the recycling targets of the Circular Economy Law.”

Erwin Binner

Opportunity: That is definitely an urgent issue. What problems need to be solved here?

Erwin Binner: Biogenic waste is an important fraction in meeting the recycling targets of the Circular Economy Law. Residual waste analyses show that, despite the organic waste regulation that has mandated the separate collection of organic waste since 1995, considerable quantities of usable biogenic waste end up in residual waste bins. We need to use this for reclamation in the future. This also involves ancillary measures to improve the quality of the organic waste that is collected.

Many composting plant operators complain about the high amount of contraries in the organic waste they get. They have to remove the contraries, which increases their costs. In order to improve the situation we need to take steps at the collection system level. That might mean publicity in order to motivate consumers to separate their trash rigorously, or using a contrary scanner or perhaps distributing a kind of “red card” to people who don’t follow the rules. This is taken into account by the new compost regulation, the first draft of which is expected soon. The regulation will define limit values for foreign matter in waste delivered for processing. The figure of two percent by mass of the damp mass is being bandied about. Plant operators can accept collected waste with a contrary content up to five percent by mass, if technical measures are in place that reduce that amount to two percent in the input material for rotting.


Opportunity: You just returned from a congress in Lima. What are the challenges in waste management for developing nations like Peru? Is our experience applicable?

Erwin Binner: BOKU entered into a partnership agreement with the Universidad Nacional Agraria La Molina way back in 1990. This agricultural university does research in similar areas as BOKU. Together we developed training programmes, seminars and congresses. For example, in the spring an international compost course was held, and a few weeks ago there was the seminar “Waste Avoidance, Recycling, Treatment and Landfilling” where 190 participants from South and Central America including Mexico discussed their research findings.

I consider events like this and the open exchange of ideas to be very important. Only in this way can the responsible parties evaluate the advantages and disadvantages of procedures in Europe, modify techniques for use in their own countries, and most of all learn from our mistakes. The good news is that we’re seeing initial successes. For example, in recent years the number of “sanitary landfills” in Peru has risen. These are landfills that meet a certain technical standard and have the corresponding barrier function. Emissions thus don’t escape completely uncontrolled like they did previously. Composting has been understood to be essential for both agriculture and waste disposal. Many municipalities and farming operations run composting plants, at a similarly small scale as in Austria. Here and there, the separate collection of recyclable and biogenic fractions has started.


Opportunity: Ms. Huber-Humer, at the start you mentioned cyclical waste management. Europe is doing its homework, even if there remains much to do. But how can appropriate solutions be found in less prosperous countries?

Professor Marion Huber-Humer: In my opinion, interdisciplinary research and the international collaboration of varied stakeholders are the keys to moving international waste management towards a circular economy. At our institute we work on these questions by systematically observing material flows and processes. In the process we always try to consider and evaluate the entire life cycle.

Here again we follow the waste management premises from avoidance, collection and reclamation to environmentally neutral disposal with minimum emissions. From this, procedures and technologies can be adapted and systems can be optimized for countries that have less money to spend on waste management. Often countries start small with projects of modest scope, in order to gain experience. These pilot projects can then be scaled up step by step. It’s important to understand the existing local structures in each country, and get them onboard early. These might be active and involved local people – the so-called informal sector that takes care of collecting and using certain waste streams. Or it might be formal organizations and education institutions up to the university level, that offer waste management education and training programmes.


Opportunity: Can you give us an example?

Professor Marion Huber-Humer: I can gladly give several. In the past years we have done many very different projects. We see over and over again that knowledge transfer and training are essential. One good example is a Tempus project supported by the OeAD, the Austrian Agency for Education and Internationalization. Together with students and colleagues from Dresden Technical University and Universities in Ukraine and Belarus, we developed waste management study programmes. In the process, in cooperation with study groups and local stakeholders, regional waste management plans were formulated.

In another project we worked with partners in Ethiopia to establish the separate collection of organic waste in a district of the capital city Addis Ababa. This waste was subsequently composted decentrally to produce a locally available fertilizer. Currently we’re participating in several projects for handling electronics waste in the Caribbean and in Laos. Among other things, the island nature of small Caribbean is a specifically regional challenge. Other projects in recent years have revolved around ship recycling and dealing with hazardous waste in China, and handling plastic waste in Vietnam. We’ve worked in Kazakhstan and Russia on modernizing management systems for residential waste, in particular towards monitoring landfills, and means and technologies for minimizing emissions.


Opportunity: In many countries, mixed household waste is the largest fraction. Can its mechanical-biological processing contribute to sustainable waste management?

Professor Marion Huber-Humer: Absolutely. In many of the foreign projects I named, we found that the timely implementation of simple, robust technologies makes a noticeable improvement in the environmental situation. The mechanical-biological treatment of residential waste is a low-tech measure that is suitable and beneficial for economically weak countries. It acts as a bridge technology, like it did in Austria twenty or thirty years ago. Back then we didn’t have enough thermal treatment capacity.

In the mechanical stage, recyclables like metal or thermally usable fractions can be reclaimed. These can be usable as primary energy sources for regional industries. But the really big benefit for the environment is in the substantial reduction of greenhouse methane emissions. If mixed household waste is processed mechanically-biologically before landfilling, the organics in it stabilize and do not decompose as easily. If this stabilized material is tipped into a landfill uncompressed, if favours the biological methane oxidation process. That means that methane formed and emitted by untreated waste in deeper landfill layers is broken down by methane-oxidizing microorganisms. The microorganisms colonize pre-treated material preferentially, and transform methane into water and carbon dioxide. Carbon dioxide is much less greenhouse-active than methane. The result is a multiple win for the environment in countries where due to the lack of legal, institutional and economic disincentives, uncontrolled dumping is still the predominant form of waste disposal.