Italian Lessons in Biowaste Collections

The separate collection of organic waste represents the largest portion of Italy's recycling industry. Intensive source-separation of biowaste is a key-factor for gaining high recycling rates and is currently applied in 4000 municipalities, involving around 40 million inhabitants. When it comes to managing organic wastes, Italian lessons are a must. by Marco Ricci Jürgensen With over 4.5 million tonnes of biowaste – a combination of both food waste and garden waste - being collected each year in Italy, and used to produce some 1.3 million tonnes of quality compost used in agriculture, landscaping, and other activities, the sector is the country's largest contributor to recycling. Surveys conducted by the Consorzio Italiano Compostatori (CIC) or Italian Biogas and Composting Consortium show that biowaste collected under optimised conditions and recycled in composting plants contribute significantly to Italy achieving both national and EU targets for recycling biowaste and reducing the amount of Municipal Solid Waste (MSW) sent for disposal. Key to achieving this success has been the door to door collection of food waste, combined with compostable bags, which enables the best-performances in terms of capture and quality - i.e. the minimisation of non-compostable materials present in biowaste collections. Separate collection Since the mid-90s CIC has been involved in developing and enforcing adequate recycling capacities for biowaste. In 1997 the Italian general Waste Act (Dlgs 22/1997) significantly altered the legal framework and vision for MSW management - the separate collection of biowaste became a strategic element to reach the recycling targets set out in the national law. Italy's official data for 2011 shows that 4.5 million tonnes/year of biowaste was separately collected and recycled in composting or Anaerobic Digestion (AD) plants. This amount rose to 4.8 million tonnes in 2012 and CIC estimates that by end 2013 the amount will reach five million tonnes. In Italy biowaste is generally collected by means of two separate collection schemes: A scheme intercepting food waste, including both cooked and uncooked food-residues and including meat, fish, etc. A scheme intercepting garden waste, with lower frequencies than food waste collection and with different collection tools and schemes. Comparing capture rates of biowaste in Italian regions shows significant differences. In northern and central Italy potential capture rates for food waste are in a range of 50-70kg per person per year (pppy), while in southern regions potential capture rates rise to 85-110kg pppy and above, due to larger amounts of food waste inside MSW. The amount of garden waste tends to decline from northern to southern areas due to climatic conditions, and is also influenced by rainfall and summer temperatures. Overall, despite the greater potential, southern regions are still intercepting organic waste for composting at a very low rate. The amounts collected in 2011 and 2012 confirm the long-term trend in Italy of biowaste collections increasing by around 5% each year, mainly due to the larger number of municipalities adopting separate collection for food and garden waste. Furthermore, the amount of biowaste recycled in Italy will increase by approximately 50% by 2020 due to the fulfilment of a national target for recycling and the extension of source separated collection schemes for food waste in southern regions. In Italian municipalities with separate kerbside collections for both food waste and most types of packaging waste, recycling rates of 50% to 70% of total MSW production are reached. To achieve such a result, the contribution of food waste and relevant packing materials is necessary. Currently, door to door food waste collection schemes are currently applied in large Municipalities such as Bolzano, Turin and Milan metropolitan area, were the population density varies between 3000 to 7000 inhabitants per square km. Figure 1: Separate collection of MSW in Italy with specific contribution of food waste and garden waste– year 2011 Quality control Designing a collection scheme that clearly distinguishes between food waste and garden waste, according to their bulk density and seasonal production rates, has specific operational advantages. The introduction of small buckets of up to 30 litre capacity for food waste collected at semi-detached and detached houses (with gardens) significantly increases the speed of the collection team relative to schemes adopting only trolley bins and road-containers that need a mechanical lifting device. Door to door collection schemes require that households be made responsible for the maintenance and cleaning of the receptacles (buckets, bins, etc.) assigned to them. This can be achieved by providing each household/producer with specific tools such as bags that can be used to easily manage the more critical putrescible fraction - i.e. food waste. Contamination from post-consumer plastics, present either by error or by negligence, in source separated food and garden waste represents a problem for composting facilities. Compostable bags, complying with the EU-standard n°13432, used for the separate collection of food waste can significantly improve the quality of collected organic waste. According to CIC's data, if collection at households is carried out with PE-bags, the expected content of non-compostable materials (NCM) is about 9%, while if the collection is performed with compostable bags the level of NCM can drop to 1.4%. So the bioplastic sector potentially can enhance the recovery process of biowaste delivered to composting and biogas plants - if the bioplastics used for separate collections are compostable. Since 2011 the demand for bioplastic bags in Italy has increased due to specific regulatory prescriptions aiming to reduce the environmental burden of plastic packaging and specifically forbid biowaste to be collected in traditional plastic bags. According to Italian National Law on waste management (Decree 152/2006), bags and liners for separate collection of biowaste must comply with the EU-standard on biodegradable packaging materials. According to CIC's surveys (see Figure 2) between 2011 and 2012 the percentage of plastic bags used for source separated biowaste reduced from 46% to 29%. Meanwhile, the quota of oxo-degradable plastics or plastic with additive increased from 10% to 19%. Figure 2 For this reason the CIC is vigorously working with national and regional waste management authorities to assure that certified compostable bioplastics are used for the separate collection of biowaste. Keeping it clean Compost quality derives from feedstock composition and purity. Hence, since 2004, the CIC has been continuously monitoring the quality of source separated biowaste, and performed about 2200 waste characterisation analyses leading up to the years to 2012. By 2011 the average non-compostable quota of biowaste delivered to Italian composting plants was 5.4% by weight, with best-practice cases showing less than 2.0% impurities. The non-compostable-quota (NCQ) consists of a variety of different plastic items such as bags and cups, etc., as well as other non-compostable materials such as glass, stones and metals. A distribution of sorting analysis performed in between 2008 and 2011 by CIC showed that 27% of the analysis show a NCQ below 2.5%, about 58% of the analysis show a NCQ below 5%, and 87% of the analysis show a NCQ below 10%, in weight of the source separated food waste. CIC has also investigated the link between biowaste quality (i.e. the NCQ) and the type of collection scheme in place. These data show that when switching to a kerbside collection scheme, from a road container or bring scheme for biowaste, both the amounts and the quality of biowaste collection increases remarkably. In addition, the expected NCQ changes from the 6 to 12% range to 1.2 to 5%. This reduction confirms previous well documented investigations for both Italy and other countries. Figure 3: Bags and shoppers of different materials used for source-separation of food waste - Italy Composting and AD in Italy Biowaste from source separated municipal collections accounts for around 80% of all organic waste recycled at Italian composting plants in 2011. In the case of AD facilities treating waste it accounts for about 90% of input feedstocks. Back in 1993 there were just 10 composting plants accepting biowaste in Italy. By 2011 that number had risen dramatically to 252 operational plants, with 149 having an annual capacity exceeding 10,000 tonnes. The composting sector currently represents 40% of all MSW recycled, thus being Italy's largest recycling industry with an annual estimated turnover of at least €390 million euro. In 2012 the overall authorised capacity of plants (nearly seven million tonnes) , including those not yet constructed, far exceeds the amount currently treated, signifying that the growth of collection systems will find treatment capacity as these plants are built. Current surveys performed on incoming organic waste into Italian composting facilities show that food waste represents the largest portion, up to 48%, of input materials. Garden waste is almost 32%, while sewage sludge accounts for 11%. As a result, source separated urban biowaste accounts for almost 80% of the overall organic waste recycled in Italian composting plants. The quality of biowaste, in terms of percentage of compostable material, collected is a key aspect for producing quality compost. Over recent years, AD has been steadily increasing. This form of treatment is chosen in almost all newly opening biowaste facilities. The general approach in Italy is to couple AD with composting, with the compost obtained from source separated feedstock having End-of-Waste status. In 2011 the AD-sector produced about 81 million Nm3 of biogas with an average yield of 160 Nm3 of biogas per ton of input material. In Italy the role of compostable bioplastics has been key in driving the quality of the output material CIC's QAS for compost In 2011 the composting sector produced over 1.3 million tonnes of compost from separately collected feedstocks. Compost has the status of a product in Italy and about 70% of it was used as a fertiliser on crops while 30% was processed to manufacture garden and landscape products. High quality compost is of added value to producers and end users, and improving quality has been an objective for CIC since its early years. In 2003 the association started the Italian certification scheme for quality compost to enhance the quality of compost production and make customers aware about the advantages of compost use. Today the scheme involves around 40 plants and more than 30% of the compost sold in the Italian market has gained CIC's quality compost label. Conclusions The quality of source segregated feedstock is a necessary condition for allowing composting and AD to effectively recycle these organic waste streams into both renewable nutrients and energy. Kerbside food waste collections combined with compostable bags are showing the best performance both in terms of capture and quality. According to the long-term trend for recycling biowaste in Italy, a recycling rate of around 50% should be achieved by 2020 thanks to the national target for recycling and the extension of source separated collection schemes for food waste in the country's southern regions. Marco Ricci Jürgensen is a technical officer at the CIC. This article is based on a presentation given by Marco Ricci Juergensen; Massimo Centemero; Werner Zanardi, Dario Dall'Anna at ISWA's International Conference 2013 in Vienna. E-mail: ricci@gmail.com This article is on-line.