BIOLOGICAL WASTE TREATMENT IN EUROPE - TECHNICAL AND MARKET DEVELOPMENTS

Abstract
Investigations in Europe indicate that quality and marketing of the end product are the most crucial composting issues. Both producers and users are of the opinion that sustainable recycling of organic wastes demands clear regulations with regard to what is suitable to be recycled and how it should be managed and controlled. Around 15% of the estimated total recoverable potential of 60 million Mg of organic waste is presently treated biologically in Europe. The re-use has to meet environmental and market requirements. Therefore, the trend in Europe goes definitely towards source separation of the organic residues from gardens and households. Quality requirements for composts regarding heavy metals, organic pollutants and hygiene allow no other alternative. There is no longer a market for mixed-waste compost. The introduction of source separation and composting must go hand in hand with the introduction of a quality assurance system for compost plants. Assuring compost quality entails more than just fulfilling a number of heavy metal limits. Levels and ranges of the quality criteria for compost differ very much in Europe. In most countries, independent monitoring of sampling and analysis takes place or is in preparation. A quality label or certificate will be given to compost, which meets the monitored quality criteria.

1. Introduction

Recent years have seen a phenomenal increase in the biological waste treatment in Europe. Looking ahead, we must assume that at least 32 % of urban waste and a large proportion of industrial waste - approximately 40 % of the total waste production in Europe - could be biologically treated via composting and anaerobic digestion. The final products from the treatment are usually used as soil improvers or as fertilisers. They have to meet environmental and market requirements which will lead to an improvement of the compost quality produced in Europe in the future.

2. Waste quantities and source separation in the EU member states

The collected and treated amounts of organic material differ much in the EU countries. Around 35 percent resp. 17 million Mg (see table 1) of the estimated total recoverable potential of the 49 million tons bio- and green waste is presently separately collected. This results in a compost production of around 9 million Mg in Europe.

Table 1: Amount of separately collected and composted bio- and green waste in EU

Country	Sep. collected + treated organic waste [in Mio Mg]		Recovery potential of organic waste [in Mio Mg]		Theoretical potential1)
	Biowaste	Green- waste	Biowaste	Green- waste	Total [Mio Mg]
A (2000)	0,45	0,20	1,22	0,97	2,19
B (2000) Flanders	0,34	0,39			1,3
B (1994) Wallonia	0,12				0,16 in 2002
D (1999)	7,0				9,0
DK (1999)	0,037	0,65	0,1	0,66	0,76 in 2004
F (2000)	0,05	1,5	5,25	3,5	8,75
Fi (1998)	0,1				0,6
GR (1995)	-	-			1,8
I (1999)	1,5				9
IRE (1998)					0,44
Lux (1998)	0,03				0,06
NL (2001)	1,6	1,5	1,7	1,5	3,2
P (1995)		0,01			1,3
ES (2000)	0,03 (Catal.)	0,02 (Catal.)			6,6
SW (1999)	0,14	0,15	1,0	0,65	1,65
UK (2000)	0,039	1,0			3,2 in 2006
Sum	11,4	5,42			48,7
Treated Bio- + Greenwaste 16,9 Mio. Mg			Theoretical recovery potential 49 Mio. Mg

 1) In most or the European countries no statistical data about the home composting are available, so an estimation about full extent of the potential of organic waste is very difficult.

The composting of mixed municipal solid waste (MSW) is no longer state of the art and becomes more and more unusual and can be seen only in the few countries in southern Europe. In these countries, however, a change in the waste management also begins because it is obvious that in future there will be no market for composts with bad qualities - such as e.g. mixed municipal solid waste composts. Compost products based on source separated organic waste show only 10 to 20 percent of the heavy metal contents compared to MSW compost and can reach the same quality level as the one produced in private gardens. This suits the requirements especially to those of professional compost users.

3. Waste policy in Europe

Concerning their organic waste activities Europe can be divided into 4 categories (Figure 1). In Austria, Belgium (Flanders), Germany, Switzerland, Luxembourg, Italy, Spain (Catalonia), Sweden and the Netherlands the policy is countrywide implemented. These countries of the first category recover around 80 percent of the at present separately collected and treated (mostly by composting) organic waste fraction in the EU. Digestion plays a minor part at the moment.

Denmark, UK and Norway form the second category of the implementing states. These countries have build up parts of the political, quality and organising framework for separate collection and composting. Finland and France form the third category. These countries have developed strategies and are at the starting point. In the forth category we find countries where no effort on composting of source separated organic waste can be detected like parts of Spain, Greece, Ireland and Portugal. These countries still compost mixed urban wastes.

Figure 1: Development of source separation and composting in Europe

 

As a summary the policy in Europe shows an extensive trend and a fast development towards source separation of organic waste. In most countries home composting is part of this policy.

4. Compost quality and quality assurance

Many investigations in Europe indicate that quality and marketing of the end product is the most crucial composting issue. Both producers and users are of the opinion that a sustainable recycling of organic wastes demands clear regulations regarding what is suitable to be recycled and how it should be managed and controlled. A well-founded quality assurance programme would definitely increase sustainable recycling of organic wastes.

Marketing analysis over recent years show that all users of compost demand a standardised quality product that is supervised by independent organisations. A study in the south of Germany showed that 94% of the commercial users made this a precondition. In another German study among citizens of Cologne and Düsseldorf 80 % of the participants would have a more positive attitude towards compost and food grown on arable land with compost application, if they were sure that a quality control system for compost exists.

The introduction of separate collection and composting must therefore go hand in hand with the introduction of a quality assurance system. Assuring compost quality is more than just fulfilling a number of heavy metal limit values. It plays a central role and influences all stages of the treatment of organic residues:

- Separate collection
Quality assurance can be used to draw conclusions on the quality of the source separation and can introduce measures for improvement.
- Plant engineering
Errors in the plant engineering can be quickly identified via quality controls. In the hygienic sector quality assurance also serves to guarantee worker protection.
- Compost production
Only constant quality and product checks avoid errors in compost production.
- Marketing
Consumers want a standardised quality compost. Only a quality assurance system guarantees this. The quality sign as a symbol helps the marketing efforts.
- Public relations work
A good image for compost can be built up with assured quality and a quality label.
- Application
The analytical results form the basis for the declaration and the recommendations for use and consequently for the correct and successful application of compost.
- Product range
Only by precisely knowing the constituents and their width of fluctuation several compost products can be developed.
- Politics/legislature
Through statistical evaluation of the test results the legislator is familiar with the present standard of compost and the possibilities of the composting plants and he can issue directives that are appropriate for the current practical situation of the compost quality.
- Certification
A quality assurance system is a pre-condition for certifying the composting plants to e.g. the EU-Standard EN ISO 9002.

The central role of quality assurance is seen in the countries with developed composting system like Austria, Germany, Denmark, the Netherlands and Belgium. These countries have established an extensive quality management for the composting plants, in which around 400 composting plants take part at the moment. Several other countries like Sweden, Norway, Italy and France are in the status of the conceptual design.

4.1. Elements of quality assurance systems

Depending on intention, philosophy, political or functional approach, the quality assurance systems for compost comprise different elements:
- Raw material
- Intake control
- Limits for harmful substances
- Quality criteria for the valuable constituents in the compost
- Composting production
- External control (product and/or production)
- In-house monitoring
- Quality label for the product
- Certificate for the plant and/or the product
- Declaration of the properties of compost
- Recommendations for use and application
- Training and qualification of the operator
- Management and operation of plants (plant assessment)
- Annual certificates

4.2. Quality of compost and quality management

When considering the introduction of composting, the end product should merit equal or even more attention than the composting process and the composting technique. Quality assurance of compost plays hereby a central role. It links the end product to all the elements of the organic treatment and cycle and forms the first step to a comprehensive quality management of the composting plants.

Table 2: Survey on compost quality efforts in various countries

Country	Status of quality assurance/certification of compost
Austria	Fully establish quality assurance system
Belgium	Fully establish quality assurance system in the Flanders region, the Wallonia and the Brussels region will probably follow the Flanders example.
Denmark	Just started with quality assurance system for compost (Criteria, standardised product definition, analysing methods)
France	Proposal for quality criteria, Research program for a quality management system
Germany	Fully established quality assurance system for compost and digestion residuals
Italy	Successful source separation system
Luxembourg	Some plants according to German Quality Assurance System
Netherlands	Fully established quality assurance and certification system
Spain	Proposal for ?Bill on the Quality of Compost? in Catalonia
Sweden	Just started with quality assurance system for compost and for digestion residuals
UK	Proposal of quality standard by the Composting Association TCA
Finland	No official efforts until now
Greece	No official efforts until now
Ireland	No official efforts until now
Portugal	No official efforts until now
Other Countries
Norway	Criteria and requirements for 3 quality classes
Switzerland	Product definition and analysing methods
USA	- Published analysing methods - Plans for product definitions for MSW compost
Canada	Final step of discussion of a quality assurance system for source separated organic waste
Australia	Proposal of quality criteria and analysing methods

The central role of quality assurance is seen in countries with a developed composting system like Austria, Germany, Denmark, the Netherlands and Belgium. These countries have established an extensive quality management system for the composting plants, in which around 500 composting and 30 digestions plants take part at the moment. Several others like Sweden, Norway, UK and France are at the stage of the conceptual design.

4.3. Status of Quality assurance in EU

Statutory quality standards including a continuous monitoring or a voluntary quality assurance system exist in most of the European Countries. In Austria, Belgium (Flanders), Germany, Luxembourg, The Netherlands and Sweden 520 large composting and digestion plants - controlled by a qualtiy monitoring system - treat around 70 % of the soutce separated organic waste in Europe. In Norway, Denmark and UK similar quality assurance systems are in development. In Portugal, Italy, Spain, France and Ireland developments for quality standards are in progress.

Table 3: Status of quality assurance of European composting and digestion plants (Dec. 2001)

Country	Plants with quality assurance1)	Plants with quality sign or certificate
AT	10	2
BE (Fl)	22	10
LUX	3	3
NL	22	4
D	429 composting, 16 digestion	400 composting, 10 digestion
SWE	2 composting, 8 digestion	-
DK	(draft of quality assurance system)	-
NO	(quality assurance system exists)	-
UK	(quality assurance in introduction)	-

1) The table includes plants that have applied for a quality sign/certificate but the process is not yet finished

4.4. Type of control systems

An essential difference between the European countries lies also in the amount in which the compost production is included into quality assurance. The RAL-quality sign of Germany has the philosophy to assess the quality of the end product. Iin the Netherlands and in Belgium there is an aspect of two different attitudes. Here the control of the end product is combined with a production control. In Belgium the period for application of a new compost plant for the quality sign is two years, whereas in the first year a continuous production monitoring is made. The second year of application follows only the control of the produced compost.

Table 4: Range of control systems

Range of Control Systems for Composting Plants in Europe
	Production monitoring	Product control
Austria	Compost Ordinance	Compost Ordinance and KGVÖ
Belgium/Flanders	VLACO - during the first year of operation	VLACO - beginning with the second year
Denmark	-	Plant Directorate
France	According to ISO 9000 principle in the Qualorg research project	According to ISO 9000 principle in the Qualorg research project
Germany	BGK 1)	BGK
The Netherlands	KIWA	KIWA
Sweden	RVF Certification	RVF Certification
UK	TCA ? procedures and records checked for each assessment period	TCA ? sampling, results, product storage and labeling checked for each assessment period

1) only for hygiene issues

The certification for the quality sign in the Netherlands describes a very large internal quality monitoring of the compost production with weekly tests of parameters from each compost charge. Similar tendencies can be observed in Austria where the quality sign demands a product/process diary with nearly hundred positions.

4.5. Quality criteria

The quality criteria for compost vary in the European countries concerning the amount, the requirements and the limited values. Direct quality classes based on heavy metal limits exist only in Austria (class I and II such as the types "A" fresh and "B" matured compost) and in the Netherlands (Table 5). The Dutch requirements for the class "very good compost" are so high that they can only be reached in exceptional cases; thus the compost plant association is trying to obtain an alteration of the parameters. A quality standard with two steps in Belgium, with composts for arable land and for other areas, did not prove to be practicable, thus composts can be distinguished only on a raw material basis.
Evidence has been made by diversified compost qualities based on heavy metal content that only the best will be asked for. The large quantity of good quality compost which is sufficient for various uses will fail to be used in most cases.

Quality classes based on raw material (Belgium/Fl), on the properties or the ranges of utilisation (Germany) will more effectively meet the requirements of the compost market.

Table 5: Classification of compost and digestate quality in Europe

Country	Type of compost/quality class
Austria	Quality Class A+ (organic farming), Class A (high quality) and Class B (minimum quality/noon food production areas)
Belgium/Fl	Yard and Vegetable, Fruit and Garden VFG Compost
Denmark	Organic household waste compost with no classification up to now. No quality criteria for green/yard waste compost necessary.
Germany	Fresh and matured compost, mulch and potting soil compost solid and liquid digestion residues
Netherlands	Compost and very good compost
Sweden	Very fresh, fresh and matured compost, digestion residues

At the moment only Denmark is worried about organic pollutants in compost and has fixed limits. The other countries have detected very low levels, so they don't analyse the contamination (Netherlands, Belgium) or they do a kind of observation in suspicious cases (Austria) or on a voluntary basis (Germany).

4.5.1. Heavy metal contents

With the stipulation of the quality criteria various philosophies are to be observed. Here we have countries such as Austria or the Netherlands with relatively severe guidelines e.g. concerning heavy metals on the one hand and on the other hand relatively high deviations (40 to 50 %) from the guide values which are allowed for the single case. These are confronted with the German guide values with relatively moderate values, but relatively little deviations of only 15 %.

Table 6:Heavy metal limits and allowed deviations in the EU(mg/kg dm)

Country	Quality Standard of	Cd	Cr	Cu	Hg	Ni	Pb	Zn
AT	Biowaste Ordinance Class A	1	70	150	0,7	60	120	500
BE (Fland.)	Agricultural Ministry	1,5	70	90	1	20	120	300
DK	Agricultural Ministry	0,4	-	1000	0,8	30	120	4000
D	Biowaste Ordinance Type II	1,5	100	100	1	50	150	400
IRE	Draft	1,5	100	100	1	50	150	350
LUX	Environmental Ministry	1,5	100	100	1	50	150	400
NL	Second Class ?Compost?	1	50	60	0,3	20	100	200
ES (Cata.)	Class A (draft)	2	100	100	1	60	150	400
SWE	Quality assurance organisation	1	100	100	1	50	100	300
UK	TCA Quality Label	1,5	100	200	1	50	150	400

Die Tabelle 6 zeigt, dass wir uns in Europa im Bereich der Schwermetallrichtwerte zumindest in der gleichen Größenordnung bewegen und eine gemeinsame europäische Bioabfallverordnung nicht mehr utopisch erscheint. Werden die zulässigen analytischen Abweichungen in den Standards beachtet, rücken die Werte noch näher zusammen. Zu hoffen bleibt, dass die strengen holländischen Werte der zweitbesten (!) Qualitätsklasse nicht als Richtschnur genommen werden.

The guide values have been proved in practice to be more efficient than the stipulation of absolute limited values resp. cut-off values. Compost plants have little influence on the input material so that a certain deviation of the quality criteria in the single case and after control should be allowed. Especially with very low limited values the compost plants are producing a compost quality which is ranging at the limit. After the composting his finished it can be analysed finally whether the compost end product fulfils the requirements or not. Only a possible deviation for the single case gives the compost plant a certain security for their production.

4.5.2. Organic pollutants

At the moment only Austria and Denmark are worried about organic pollutants in compost and have fixed limits. The other countries have detected very low levels, so they don't analyse the contamination (Netherlands, Belgium) or they do a kind of observation in suspicious cases or on a voluntary basis (Germany).

4.5.3. Hygienic requirements

In Austria the composting process has to be controlled after the first running of the plant and after each essential change of the equipment. During the regular decomposition process the temperature in the composted material has to reach 64°C over 4 days. In Germany the selected decomposition process must lead to a sanitated, hygienically unreproachable product and assure the exclusion of germs. The compost plant must be able to prove the hygienic effectiveness which is normally done by a daily temperature recording. The temperature level has to show in open composting systems more than 55°C over two weeks or 65°C over one week, in closed systems one week with more than 60°C is sufficient. With the new German Biowaste Ordinance (BioAbfV - Oct. 98) the epidemic and phytohygienical clearance of products from biological waste treatment are stated by a direct and an indirect process control together with end product tests (on salmonella).

No hygienic standards exist until now in Belgium. Denmark defines two standardised process types which should guarantee sanitation. Controlled composting has to show the over 55°C during more than two weeks, controlled deactivation takes place after one hour at 70°C. Because of the variations in the technology of the composting plants a new regulation for hygienic aspects was laid down in the Netherlands in 1998. The former standardised general process parameters (minimum 8 weeks composting, and from these 4 weeks intensive with aeration and re-stacking twice, 50 - 60°C temperature) which guarantee hygiene efficiency are replaced by an individual solution for every composting plant. The Dutch independent certification organisation KIWA strongly supervises the strict adherence to the therefore required process parameters.

In future an extension of the hygienic requirements in Europe can be expected. Thus the latest draft of the new German compost ordinance asks for a hygienic process test of the total compost plant every two years. Austria is likely to follow this example and plans according to a draft version of the new Austrian compost decree an additional hygienic control of compost bags at the point of sale.

4.5.4. Additional quality aspects

The fulfilment of the requirements for heavy metals, organic pollutants, hygienic requirements and further characteristics are the preconditions for the award of a certificate (Netherlands) or of a compost quality label (Austria, Belgium/FL, Germany, Sweden).

These additional quality criteria concern impurities (plastics, metals, glass, stones), organic matter, plant compatibility, degree of decomposition, salt and water content. The detailed declaration of the contents of the compost to be sold is of a great importance in all countries. Only with the exact knowledge of the characteristics compost can be used successfully.

The quality of composts can not be improved that much in these countries. Statistical data from the German Compost Quality Assurance Organisation FCQAO show a reduction of e.g. the heavy metal content of zinc and cadmium only of two or three percent over the last 10 years despite of a lot of efforts of the composting plants. So it can be expected that the compost quality has reached the inevitable background level.

6. Compost quality and marketing/public relations

Marketing and public relation of compost requires a standardised quality product too. Composts which have been tested in a quality assurance system meet these requirements because:
- Quality assurance is a good basis for sales promotion, for public relations work and a good argument for the building up of confidence in compost.
- The quality label allows the establishment of a branded "quality-tested compost" and a positive compost image.
- Regular analyses during compost production guarantee a quality-assured product.
- Standardised analyses carried out in accordance with specified methods enable a nation-wide objective assessment of the compost.
- The investigation results form a basis for the product declaration and the application recommendations.

The result is a compost of defined quality which is therefore marketable and saleable on a large scale.

Further marketing activities are necessary, as compost with a quality label or a quality certificate will not be sold by itself. With this qualification, however, the compost plants have an excellent start because quality products always have advantages in the market. In order to compete with the activities of the peat-, soil- and bark industries the compost plants need to undertake common efforts in their marketing activities on a similar level.

The quality assurance organisations (e.g. the compost quality assurance organisation in Germany, KGVÖ in Austria, VLACO in Belgium, VVAV in the Netherlands) support the compost plants in their joint marketing activities. It is neither necessary nor financially sensible that each compost producer develops its own marketing instruments.

The marketing measurements in the individual EU countries vary decisively in size and volume. There are only actions in countries with a developed compost management. An advantageous start of a marketing strategy is to build up a quality assurance/certification with recommendations for the use of compost for the most important ranges of product sales. (User brochures of the German Compost Quality Assurance Organisation, 2-volume guidelines for practical use of compost of VLACO in Belgium, 6 user information sheets of the KGVÖ in Austria). The Belgium VLACO supports additionally a row of tests for the use of compost.

7. Compost use and markets

Significant differences on the market situation are to be recognised also in the EU countries. Generally it can be recognised that even in the developed countries with a circumstantial compost production like Germany the feared problems with compost sales did not occur. In all the countries hobby gardening, horticulture and landscaping is a successful market and has good developing chance.

Table 8: Market shares of compost sales in EU (Status 1999 to 2001)

Marktanteile in %	AT 2000	BE (Fl) 2000	D 1999	DK 2000	NL 2001	IT 2001	LUX 2000	FR 2000
Landscaping	30	26	25	13	10	15	28	19
Landfill + Restoration	-	2		14	-
Agriculture + Special cultures	301	9	43	12	75	33	43	52
Horticulture	10		5	8	-			5
Earth works	5	35	10	-	-	48		15
Privat gardens	20	19	14	43	10		18
Export		5	-	-	5
Miscellaneous	5	4	3	10	-	4	11	9

1) 60 % of the Austrian VFG and green waste is on-farm-composted

Compost marketing shows several trends in Europe. Green compost is an organic fertiliser and soil conditioner accepted by the markets all over Europe. It can be produced in a good quality without much technical equipment. The biocompost market shows two contrary developments: By means of the decreasing or low tipping fees, some of the composting plants try to minimise their treatment and marketing costs which results mostly in delivering the compost free of charges to farmers without additional marketing efforts. On the other hand a lot of composting plants start to add value to their compost products and produce mixtures or special products according to customers needs and market requirements. They co-operate with earthworks or build one by themselves. The quality assurance organisations support these tendencies in organising research projects for compost application and for new compost products.

Figure 2 gives a European perspective on ranges of value (and market size) for composted materials. It can be seen that there are a variety of uses for compost with different potential market sizes.

Figure 2: Compost Marketing Hierarchy Indicating Market Prices and Volumes

 

Note: The volume is indicated as the relative size (small (S) to extra-extra-large (XXL)) of the market segment. Prices are known ranges for compost products within the market segment (EUR/m³).
Sources: M. Carlsbæk, SOLUM, personal communication), in F. Amlinger (2000) Composting in Europe: Where Do We Go? Paper for the International Forum on Recycling, Madrid, 14 November 2000.

8. Conclusion

The European compost market requires best quality like the development in Belgium, Denmark Germany, Netherlands, Austria and Switzerland shows, which already own a highly developed compost management. The quality standard of the composts must stand the competition on the market with peat-, earth- and bark products. This is only possible with organic raw materials from separate collection and via a distinct quality assurance programme to be handled by the compost sites.

References
(1) M. DE GROOT : "Composting in the European Union" - Report in assignment of the European Commission DG XI., DHV, Amersfoort, The Netherlands, June 1997

(2) J. BARTH, N. ZÖLLER, H. STÖPPLER-ZIMMER : Quality assurance and regulations of composting and compost application in five European countries. AFR report (in printing), Stockholm, Sweden, 1998.

(3) W. BIDLINGMAIER ET AL.: BioNet - Biological Waste Management in Europe, Internet address: www.bionet.net, 1998

(4) GERMAN COMPOST QUALITY ASSURANCE ORGANISATION BGK:

Dipl.-Ing., Dipl.-Journalist Josef Barth
INFORMA Compost Consultants
Am Landhagen 64a, D-59302 Oelde, Germany
Tel.:+49 2522 96 03 41 - Fax: +49 2522 96 03 41 - Email: Barth@oelde.com