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Type of Waste to be treated
Source Separated Organic Waste
Source Separated Packaging
Mixed MSW
Min Capacity (in tonnes)
Secondary Products or Energy Production
Max Residues (%)
Capital Expenditure € tn of total feedstock on wet basis
Annual operation and maintenance cost € tn of total feedstock on wet basis
Land requirement m2 per tn of total feedstock
Water consumption m3 per tn of total feedstock
Case Studies PDF Print E-mail
1.  General
2.  Mechanical Biological Treatment Plant in the West Attica Region, Greece
3.  Mechanical Biological Treatment Plant in Chania, Greece
4.  Mechanical Biological Treatment Plant in Kalamata, Greece
5.  Composting Plant for Solid Waste at the Landfill Site in Piatra Neamt, Romania
6.  Composting Plant in Vrhnika, Slovenia
7.  Composting Plant in Puconci, Slovenia

1.         General

As proved by the results of the analyses of the composition of municipal solid waste that took place in both Romania and Bulgaria by the SUROVINA working team, the generated waste is characterized by high organic content. Therefore, the potential for the application of biological methods in Romania and Bulgaria, as well as the whole Balkan Region is very high. Specific case studies of biological methods applied in Greece, Romania and Slovenia are described below. More specifically, information is provided about indicative mechanical biological treatment facilities in Greece and indicative composting facilities in Slovenia and Romania.


In Bulgaria currently no composting, anaerobic digestion or MBT treatment plants are operating and only home composting takes place in 25 municipalities including 5,500 households.


Greece is considered to rely heavily on MBT/mixed waste composting to deliver its Landfill Directive obligations, as shown by the relevant infrastructure that has already been developed (Kalamata, Ano Liosia, Chania, Heraklion and Kefalonia). The composting unit in Kalamata was the first that was built and operated in Greece from 1997 – 2002 with certain problems and difficulties mainly originating from the fact that no schemes for the separate collection of organic waste were applied. Nowadays, the idea of trying to put this unit in operation phase again is also seriously discussed. Regarding the unit in Chania, according to 2008 data, 34 tones of biodegradable waste are composted every day (8,900 tones on annual basis). In Athens, there is one MBT plant in Ano Liossia, covering approximately 20% of the whole waste produced in the area, and produces RDF and low quality compost. During 2009 a biodrying facility started its operation in Heraklion in Crete (75,000 tn/year) and a MBT facility in the island of Kefalonia (25,000 tn/year).


Currently, eight (8) aerobic treatment (composting) facilities for bio-waste and two (2) anaerobic treatment facilities are operating in Slovenia. Both anaerobic digestion plants are processing organic waste including bio-waste. The anaerobic digestion plant of Bioenerg has an installed electrical capacity of 1,460 kWe and the one of Koto d.d. 526 kWe. Totally 13 anaerobic digestion plants are operating in Slovenia treating various feedstocks. Apart from the composting and biogas plants some mechanical – biological treatment units are also in operation.


Currently five composting facilities are operating in Romania. The existing facilities are treating mainly green waste from parks and gardens and a small part of household organics. Additionally, one composting facility in Region 3 South and one composting facility in Region 2 South-East are under construction.


2.         Mechanical Biological Treatment Plant in the West Attica Region, Greece

The Ano-Liosia Integrated Waste Management Scheme is situated in the Western suburbs of Athens in Greece. The entire processing plant comprises of a landfill, an industrial unit of incineration of hospital waste and an MBT scheme (Figure 1) for waste. The latter includes a large composting facility. The MBT part for mechanical recycling of waste is the largest one in Europe and one of the largest in the world. It receives waste from the Attica region. Currently, the population of Attica exceeds 4.5 million people. The plant was designed and constructed after an international tender, which was procured by the Association of Communities and Municipalities of the Attica Region (ACMAR). ACMAR is the Public Authority responsible for the management (treatment, recycling and disposal) of Solid Waste of about 95% of the population of the Attica Region. The construction of the factory of Mechanical Recycling was funded by the European Union and by the Greek government.


The MBT plant constructed by ENVITEC is located in Ano Liosia, next to the sanitary landfill of West Attica and it occupies an area of 178,000m2. It has a treatment capacity of 1,200 tn of MSW and 50 tonnes of green waste in a daily basis which equals to 330,000 tonnes/year. The plant recycles packaging material, namely ferrous and aluminum materials and solid fuel (RDF: paper and plastic waste) as well as compost, while the remaining residues are landfilled.

Figure 1: MBT plant in Ano Liosia


The MBT consists of the following components:

A. Entrance Facilities – Weighting of waste, Unit for the Reception of Waste

B. Unit of Mechanical Separation

C. The Composting Unit

D. The refinery unit

E. Curing Unit

F. Packaging Unit

G. Wastewater Treatment Unit

H. Unit for Treatment of Air Emissions from the Composting Unit

I. Unit for Treatment of Air Emissions from the Mechanical Separation Unit.

3.         Mechanical Biological Treatment Plant in Chania, Greece

The plant of Mechanical Separation and Composting located in Chania was designed to treat municipal solid waste from a number of municipalities, which amount to 70,000 tn/yr and 10,500 tn/yr of green waste. The recyclable waste is separated from mixed waste and sorted into organic, plastic, paper, ferrous and aluminum materials, while RDF and compost is produced. Overall 65% of this quantity is recovered and put into the market, while the remaining 35% is disposed in the nearby sanitary landfill for treatment residues.


The plant is designed to operate six hours/day, 260 days/yr and the installed capacity is 2.3 MW. The total operational cost of the plant is estimated at 40€/ tn. The revenues from the sale of the compost product and of the recovered materials are approximately 15€ / tn. The net operation cost 25 - 30€/ tn.

Figure 2: MBT plant in Chania, Crete

4.         Mechanical Biological Treatment Plant in Kalamata, Greece

The MBT plant in Kalamata constitutes of a mechanical separation unit and a composting plant. It processes the total quantity of municipal solid waste generated in the municipality of Kalamata as well as a portion of the sewage sludge produced in the Waste Water Treatment plant of the town. The design capacity of the plant is 400 tn/week mixed MSW and 40 tn/week sewage sludge. In peak periods, the plant has treated up to 30% more load (520 tn/week).

Figure 3: MBT plant in Kalamata, Peloponnese

5.         Composting Plant for Solid Waste at the Landfill Site in Piatra Neamt, Romania

The primary objective of the Composting Plant for the Organic fraction of Solid Waste in Piatra Neamt is to compost as much as possible of the municipal biodegradable waste (organic fraction) aiming at reducing the needed landfill capacity. The coarse material necessary for the enhancement of the composting process include wood waste in form of wood chips from the industry in Piatra Neamt. The capacity of the composting plant is 12,000 tn/yr of organic fraction (biodegradable), with available space for a possible future extension of 5,000 tn/yr. This relates to the collected biodegradable organic fraction of the MSW. Structure fraction for the composting process to operate a structure material is necessary to ensure C/N ratio, air distribution, etc. The necessary amount is approximately equal to the organic fraction i.e. 13,000 tn/yr (structure fraction) and with an extension of 5,000 tn/yr to 18,000 tn/yr. The total design capacity of the composting plant in Piatra Neamt is 25,000 tn/yr (12,000 tn biodegradable + 13,000 tn structure fraction).


Figure 4: Composting plant in Piatra Neamt, Romania

6.         Composting Plant in Vrhnika, Slovenia

At the composting plant in Vrhnika about 10,000 tn of separately collected household waste as well as green and garden waste from the region around Ljubljana are processed. The plant comprises of an enclosed composting vessel with wheel loader, turning negative aerating curing area and a positive aerated compost storage. The material is placed in four closed boxes, turned weekly and composted for a total of four weeks. For a better control of odour emissions, the exhaust air from the curing area is treated via a biofilter. After about eight to twelve weeks, the finished compost is screened and marketed. A further increase in product quality is added by the storage of the finished compost on the pressure aerated storage area where there are also aerobic conditions until is placed on the market (mainly landscaping and horticulture). The operational cost for the composting plant in Vrhnika is 18 €/tn of waste treated.


Figure 5: Composting plant in Vrhnika, Slovenia

7          Composting Plant in Puconci, Slovenia

The composting plant in Puconci treats 4,000 tn/yr of biowaste and green waste. The plant has an open windrow composting platform with negative aeration and positive aerated curing area.

Figure 6: Composting plant in Puconci, Slovenia