Adella Letteria
The indicator measures the quantity of waste sent to biological treatment and, in particular, to composting, integrated anaerobic/aerobic treatment and anaerobic digestion. In 2024, the total quantity of waste recovered through biological treatment processes, approximately 9.3 million tonnes, increased by 518 thousand tonnes compared with 2023, corresponding to +5.9%.
A similar trend was also observed for the share of organic waste from separate collection, whose managed quantity increased from 6.9 million tonnes to approximately 7.2 million tonnes, showing a rise of 271 thousand tonnes (+3.9%).
The indicator measures the quantity of waste sent to biological treatment overall and, in detail, the quantities sent to composting, integrated anaerobic/aerobic treatment and anaerobic digestion.
To measure the quantity of waste in order to assess the effectiveness of policies promoting material recovery from waste, thereby providing a measure of the national system’s response to sustainable management strategies.
Directive (EU) 2018/851 on waste;
Directive (EU) 2018/852 on packaging and packaging waste;
Legislative Decree 152/2006 and subsequent amendments;
Legislative decree 29 April 2010, n. 75 and subsequent amendments;
Ministerial Decree 5 February 1998.
Rapporto Rifiuti Urbani - 2025 Edition
ISPRA, Italian Institute for Environmental Protection and Research.
The data used are derived from the MUD declaration database and from dedicated questionnaires sent to ARPA/APPA and plant operators, and are available on the Catasto Rifiuti website (http://www.catasto-rifiuti.isprambiente.it).
National, Regional
1998-2024
The indicator measures the quantity of waste sent to biological treatment and, in particular, to composting, integrated anaerobic/aerobic treatment and anaerobic digestion.
Information on the treatment plant system and on waste quantities was acquired through dedicated questionnaires sent to Regional and Provincial Environmental Protection Agencies, Regions, Provinces and Regional and Provincial Waste Observatories, as well as to plant operators.
The data were validated through comparison with the MUD database and through targeted checks carried out at individual plant level.
In recent years, there has been a substantial increase in the separate collection of organic waste, which has created the need to adapt the treatment plant system to the greater treatment demand. Alongside traditional aerobic treatment systems, aimed at producing soil improvers for use in agriculture, the national plant system, also through the conversion of existing facilities, is increasingly adopting integrated systems that combine aerobic treatment with anaerobic digestion. These systems therefore combine material recovery with energy recovery, while reducing emissions and using the generated and purified biogas for the production of energy and biomethane.
Data for 2024 confirm this trend, with an increase in the separate collection of organic waste (+2.6% compared with 2023) across all areas of the country. In response to this progressive growth, the biological treatment sector recorded a further increase in overall treatment capacity, from 12.3 million tonnes to 12.7 million tonnes. The national plant infrastructure continues its modernisation phase, characterised by a gradual reduction in composting-only plants (-25 operational units compared with 2023), accompanied by an increase of 5 units in the integrated treatment sector and 1 unit in the anaerobic digestion sector.
The overall system consists of 344 plants, specifically: 250 plants dedicated exclusively to aerobic treatment (composting); 66 integrated anaerobic/aerobic treatment plants; and 28 anaerobic digestion plants (Tables 1, 2 and 3).
In 2024, the total quantity of waste recovered through biological treatment processes, approximately 9.3 million tonnes, increased by 518 thousand tonnes compared with 2023 (+5.9%). A similar trend was also observed for organic waste from separate collection, whose managed quantity increased from 6.9 million tonnes to approximately 7.2 million tonnes, showing growth of 271 thousand tonnes (+3.9%) (Figure 1).
Consistently with the trend in separate collection, the analysis of biological treatment data as a whole shows progressive growth in the sector, both in terms of total quantities treated (+114% between 2009 and 2024) and with reference only to the organic fraction, whose quantities increased by approximately 106% over the same period (Figure 1).
With regard to the treatment of the organic fraction from separate collection over the period 2020-2024 (Figure 2), the data show that anaerobic digestion processes combined with aerobic treatment are those contributing most significantly to the progress recorded in recent years in the recovery of organic waste.
In particular, the composting sector, with a reduction of 25 operational plants, 3 of which were converted to integrated treatment, is affected by a progressive decline which, in the last year, amounted to 108 thousand tonnes, equal to 4.2% less than in 2023. Compared with 2020, the decrease was 734 thousand tonnes, corresponding to -23.1%.
By contrast, integrated treatment showed steady growth and, also thanks to the commissioning of 5 new plants, recorded a further increase of 272 thousand tonnes, corresponding to +6.9% and +36.1% compared with 2020. Anaerobic digestion, with the commissioning of one additional plant, increased by 107 thousand tonnes between 2023 and 2024, corresponding to +24.7% and +59.7% compared with 2020 (Figure 2).
The data analysis therefore confirms the growing interest in anaerobic processes, particularly those combined with subsequent aerobic treatment.
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Table 1: Waste composting, by region Fonte
ISPRA Legenda
a Paper, cardboard and wood waste; waste from industrial sectors, including agri-food, textile, paper and wood industries; waste from aerobic and anaerobic waste treatment. |
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Table 2: Integrated anaerobic/aerobic treatment of waste, by region Fonte
ISPRA |
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Table 3: Anaerobic digestion of waste, by region Fonte
ISPRA |
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Figure 1: Quantities of waste subjected to biological treatment Fonte
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Figure 2: Biological treatment of the organic fraction from separate collection, by management type Fonte
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Analysis of composting sector data shows that the conversion of some plants from aerobic treatment to integrated anaerobic/aerobic treatment, and the consequent diversion of organic waste flows towards this latter management option, have led in recent years to a contraction in the quantities of waste sent to composting. In 2024, the total quantity of waste treated, equal to 3.4 million tonnes, remained substantially stable, showing an increase of 0.7% compared with 2023, corresponding to approximately 24 thousand tonnes (Table 1).
By contrast, treatment of the organic fraction from separate collection continued to decrease, with the quantity treated, 2.4 million tonnes, showing a reduction of 108 thousand tonnes (-4.2%). Analysis of the management trend for individual flows shows, between 2023 and 2024, a further reduction of more than 118 thousand tonnes (-9.7%) in the quantities of wet fraction treated. The trend for the other fractions differs. An increase of approximately 54 thousand tonnes, equal to 16.2%, was recorded for waste included under the item “Other”. This increase is essentially due to the greater contribution of packaging and wood waste (+50%) and waste deriving from aerobic waste treatment (+23.6%). In quantitative terms, the increase in sludge sent to composting was higher, at +78 thousand tonnes, corresponding to percentage growth of 14.7%. Finally, green waste showed an increase of 10 thousand tonnes, corresponding to 0.8% (Table 1).
In Northern Italy, where 59.1% of integrated treatment plants and 85.7% of anaerobic digestion-only plants are located, the composting sector recorded a decrease of 19 operational units. The quantities treated, over 1.1 million tonnes, equal to 47.1% of the national total, decreased by approximately 65 thousand tonnes (-5.3%) compared with 2023. In the central regions, although the plant infrastructure increased by 3 units, the quantity of organic waste from separate collection decreased by approximately 9 thousand tonnes (-2.7%). The decrease was more significant, both in quantitative and percentage terms, in the southern regions, where the quantity of organic fractions sent to composting, approximately 982 thousand tonnes, declined by 35 thousand tonnes (-3.4%). The number of operational plants decreased by 9 units, against the commissioning of 2 additional plants in the integrated treatment sector (Tables 1 and 2).
Between 2023 and 2024, the integrated anaerobic/aerobic treatment sector was characterised by further growth in the total quantities of waste managed, which amounted to 4.7 million tonnes, showing an increase of 357 thousand tonnes (+8.2%) compared with 2023. The share of organic waste from separate collection alone, approximately 4.2 million tonnes, increased by 272 thousand tonnes (+6.9%) (Table 2).
Detailed analysis by the three geographical macro-areas of the country shows a general development of the sector, concentrated mainly in Central and Southern Italy. In particular, the southern regions, where the plant infrastructure increased by 2 additional plants, one of which was converted from aerobic treatment, recorded growth of over 105 thousand tonnes (+28.5%). In quantitative terms, the increase was higher in the central regions (+107 thousand tonnes; +25.6%), which were also affected by the start-up of 2 units, one of which resulted from the conversion of a composting plant. Growth was more limited in the northern regions, where the plant network increased by one additional plant and the organic fraction from separate collection increased by approximately 60 thousand tonnes, corresponding to percentage growth of 1.9%.
Over the last year, the anaerobic digestion sector was characterised by further development, contributing, although to a lesser extent than integrated treatment, to the recovery of organic fractions from separate collection. In 2024, the total quantity of waste sent to anaerobic digestion exceeded 1.1 million tonnes, showing an increase of 13.9% compared with 2023, corresponding in quantitative terms to growth of approximately 137 thousand tonnes. The share of organic waste from separate collection also increased, by 24.7%, equal to +107 thousand tonnes (Table 3).
In Northern Italy, where 24 of the 28 operational plants are located, an increase of 79 thousand tonnes (+23.2%) was recorded, with approximately 420 thousand tonnes of organic waste from separate collection managed, equal to 77.7% of the national total treated. As in 2023, the most substantial percentage increase was observed in the central regions, where the two operational units in Lazio, both fully operational, managed approximately 52 thousand tonnes of organic waste, recording an increase of over 23 thousand tonnes (+80.8%). In Southern Italy, the two operational plants in Molise, with over 68 thousand tonnes of organic matrices treated, equal to 12.7% of the national total, showed growth of approximately 5 thousand tonnes (+7.5%) compared with 2023 (Table 3).