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Agricultural Use of Biodegradable Waste Małgorzata Gotowska University of Science and Technology in Bydgoszcz, Faculty of Management, Poland [email protected] Anna Jakubczak University of Science and Technology in Bydgoszcz, Faculty of Management, Poland [email protected] Abstract. The main objective of the study is to present the possibilities of agricultural use of biodegradable waste. The article discusses modern technology of green waste composting. As a result of the biological decomposition of green waste, an soil conditioner was obtained. It meets all quality and quantity requirements for use in agriculture. The conducted research confirmed the hypothesis that green waste can be 100% used and reused. Keywords: waste, biodegradable waste, composting process, soil conditioner Introduction Industrial, technical and technological progress has caused an increase in demand for consumer goods articles throughout the world. Consumption grows every year, in particular in developed and developing countries, becoming even rapid consumerism. A natural situation is also a significant reduction of a lifecycle of many products, which resulted in an increase in waste generation and became a serious civilisation challenge for many countries belonging to the European Community. Waste is defined in Article 3, Section 1 of Directive 2008/98/EC as ‘any substance or object which the holder discards or intends or is required to discard’. According to Eurostat data of 2014, the total amount of waste generated in EU-28 by all business activities and households was 2,503 million tons and it was the largest amount recorded in EU-28 in the years 2004-2014. 343
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Agricultural Use of Biodegradable Waste

Sep 30, 2022

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Magorzata Gotowska University of Science and Technology in Bydgoszcz, Faculty of Management,
Poland [email protected]
Anna Jakubczak University of Science and Technology in Bydgoszcz, Faculty of Management,
Poland [email protected]
Abstract. The main objective of the study is to present the possibilities of agricultural use of biodegradable waste. The article discusses modern technology of green waste composting. As a result of the biological decomposition of green waste, an soil conditioner was obtained. It meets all quality and quantity requirements for use in agriculture. The conducted research confirmed the hypothesis that green waste can be 100% used and reused. Keywords: waste, biodegradable waste, composting process, soil conditioner Introduction Industrial, technical and technological progress has caused an increase in demand for consumer goods articles throughout the world. Consumption grows every year, in particular in developed and developing countries, becoming even rapid consumerism. A natural situation is also a significant reduction of a lifecycle of many products, which resulted in an increase in waste generation and became a serious civilisation challenge for many countries belonging to the European Community. Waste is defined in Article 3, Section 1 of Directive 2008/98/EC as ‘any substance or object which the holder discards or intends or is required to discard’. According to Eurostat data of 2014, the total amount of waste generated in EU-28 by all business activities and households was 2,503 million tons and it was the largest amount recorded in EU-28 in the years 2004-2014.
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Chart 1. Generation of waste in EU countries according to business activities and households Source: own work on the basis of http://ec.europa.eu/eurostat/statistics- explained/index.php?title=Waste_statistics/pl (accessed on: 10.04.2018) Considering the above, the European Union has taken actions and implemented waste management laws in Member States. All countries, including Poland, must adhere to the requirements of the European union. For Poland, it was 2013 in which the government adopted a new act of waste management indicating self-governments as a waste owner. They were supposed to decide on the way of receipt, transport and processing of waste collected within a commune, according to the applicable law. Thus, RIPOK and PSZOK have been established, i.e. Regional Plants for Processing of Municipal Waste and Municipal Waste Selective Collection Centres. Currently in Poland, RIPOK mechanical and biological waste processing plants include 127 facilities. It means that all of them, except sorting plants, have also composting plants, i.e. systems for biological processing of waste. The said systems are new. The oldest ones are 4 years old, the youngest – 1 year old. Some of them are owned by self-governments, some belong to private entrepreneurs. There are plants which employ modern waste processing technologies at a European or even global level. Others used less advanced technologies which prove to be effective in biological waste management, yet they might be less effective in natural environment protection. It was not easy to implement the above systems in such a short period of time, especially because Poland has had no experience on this matter so far. Implementation of the new waste management system in Poland was caused by the fact that the European union had also imposed an obligation on self-governments to subject waste management to the principles of sustainable development. Sustainable waste management requires that waste be treated in consideration of economic and ecological aspects, and social determinants. This results from the fact that waste has a material and energy value. Rational management of depleting resources requires that waste be treated as valuable resources which can be reused, processed or energy- recovered. Methodological Assumptions The main objective of this paper is to present opportunities of agricultural use of biodegradable waste selectively collected in Poland.
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The main objective shall be fulfilled with the following research tasks: 1. Presentation of the definitions of biodegradable waste and circular economy. 2. Methods of biodegradable waste management in Poland. 3. Composting as an effective method of biodegradable waste processing in industrial
conditions. 4. A soil conditioner as an effect for managing biodegradable waste. 5. Determination of chemical, biological and fertilising properties of the soil conditioner
by a certified laboratory. 6. Obtaining a decision of the Ministry of Agriculture and Rural Development on
marketing the soil conditioner. According to the research hypothesis, proper sorting of biodegradable waste at source and the application of a modern technology allows for 100% biodegradable waste management in the economy. The data is provided by REMONDIS Bydgoszcz Sp. z o.o. dealing with waste management and having a modern RIPOK composting plant for biological processing of waste. In order to prove the hypothesis, a direct observation method was applied and an experiment was conducted which involved composting of two samples of biodegradable waste of a total weight of approx. 400 Mg. Then, samples of composted material were taken through the Research Station and sent to the Institute of Soil Science and Plant Cultivation in Puawy. The institute has conducted research and issued opinions required to complete the procedure of obtaining a decision from the Ministry of Agriculture and Rural Development on using the soil conditioner for agricultural purpose.
1. Circular economy and biodegradable waste
Circular economy is a conception according to which products, materials and resources should remain in the economy for as long as possible, and waste – if any – should be treated as recycled material which can be recycled, processed an reused. This differentiates this economy from linear economy based on the ‘Take, Make, Waste’ principle, in which waste is usually the last life cycle of a product.
Fig. 1. Circular economy conception Source: http://www.polskirynekwegla.pl/goz-start, accessed on: 12.04.2018.
Resources
Recycling
Project
Residual waste
Circular economy
On 2 December 2015, the European Commission presented a circular economy package. Circular economy activities presented by the European Commission include, but are not limited to:
− development of environmental standards for recycled materials, in order to increase the potential of their use on the market,
− implementation of a plastics strategy referring to the matter of recycling, biodegradability and presence of hazardous substances in plastics, and for sustainable development purposes aimed at reducing the amount of marine litter,
− actions intended to limit food waste, i.e. to reduce the amount of food waste by half until 2030,
− an amendment to the resolution on fertilisers, facilitating identification of organic fertilisers and fertilisers produced from waste on the market, and supporting the role of biological nutrients,
− water reuse-promoting activities. It is planned that the implementation of all solutions proposed by the European Commission will let us achieve the level of 65% for municipal waste recycling and 75% for packaging waste recycling until 2030. The stream of waste intended to be stored is to be max 10% by 2030. A ban on storing sorted waste will also be introduced, including a complete ban on storing biodegradable waste. These requirements have been imposed on all European Union countries, including Poland. Therefore, biodegradable waste is a perfect example of waste fitting in very well with the circular economy conception. The Act on Waste (2001) defines it as ‘waste that can go aerobic or anaerobic decomposition with the use of microorganisms’. Biodegradable municipal waste includes:
− paper and board, − clothing and natural material textiles (50% of textile fraction), − green area waste, − kitchen and garden waste, − wood.
The above waste is biodegradable, however, mainly green waste is used for fertilising purposes in agricultural applications. A. Jdrczak and K. Haziak (2005) stated that green waste covers waste from public areas. This includes cut grass, tree cuttings, roadside greenery, sorted municipal waste, forest management waste and – primarily – kitchen gardens. According to the catalogue of waste contained in the Regulation of 27 September 2001 (Regulation of the Minister... 2001), urban green space care waste can be classified as municipal waste (code 20), the sub-group of ‘garden and park waste, including cemetery waste’ (code 20 02), which includes the following: − 20 02 01 – biodegradable waste, − 20 01 02 – soil and earth, including stones, − 20 01 03 – other non-biodegradable waste. Green waste comprises 4 groups of waste: green grass mass, old plant mass, tree leaves, chips and sawdust (Table 1). Table 1. Characteristics of materials classified as green waste
Material Characteristics
High content of fertilising components and moisture Susceptibility to biological changes, rate of biological processing
Old plant mass (from lawns, gardens) Different plant age and degree of woodiness Species and dimension differentiation
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Different degree of decomposition, staleness Low moisture Medium content of fertilising components
Tree leaves
Waste generated in autumn In respect to grass: less fertilising components, more metals Medium moisture
Chips and sawdust
Very high content of carbon organic substance Minimum content of other components and water High woodiness degree, resistant to decomposition High calorific value
Source: K. Sklamowski editor, ‘Poradnik gospodarowania odpadami’ (Waste Management Guidance), vol. II, issue: Verlag dashofer, Warszawa 2002, p. 5. Biodegradable green waste constitutes a valuable material, which – after the composting process – can be used to obtain a soil conditioning material. Processing of this type of waste contributes to the completion of assumptions concerning the reduction of municipal waste stored on landfills.
2. Composting as a method of biodegradable waste management in industrial conditions
REMONDIS Bydgoszcz Sp. z o. o. processes green waste in the composting process, using the Dutch technology. A certified soil conditioner is obtained in the above company, which is received as a result of biological processing of organic substance, involving biodegradation through different groups of microorganisms in aerobic conditions, at proper temperature and humidity. The structural material is separated mechanically from green waste (selective collection). This includes organic waste: cut grass, leaves, fragmented branches, straw, sawdust, wood and bark. Biodegradable waste supplied to the composting plant is sent for unloading once it has been weighed on a weighing terminal. Waste intended for composting is unloaded on a separated yard which serves as a point for preparation of waste for composting. The waste preparation process involves: fragmentation and mixing. Then green waste is moved to a special buffer with a loader, where it is stored for 1-3 days in order to collect a proper amount of waste (200-220 Mg) for loading in a reinforced concrete composting plant tunnel, where the first phase of intensive composting runs. The phase of intensive composting runs in reinforced concrete tunnels for about 16 days. Each reactor is equipped with a set of sensors and a system for aeration and irrigation of the processed material. With this, it is possible to conduct the process in strictly controllable conditions, ensuring an optimal composting effect. For remixing, proper aeration and even irrigation, after 8 days, the material is reloaded to the second tunnel where it is composted for the next 8 days.
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Fig. 2. Green waste composting phases Source: http://gmgroup.biz/kompostownie/ (accessed on: 10.04.2018) Then, the material is moved to a roofed prism yard with a loader, where it undergoes further processing, i.e. maturation. Each unloaded material is formed into prisms of the following dimensions: height – 1.7 m and width – 3 m. The material is regularly (at least 2 times a week) turned over to ensure restoration of a porous structure of the prism and its aeration. Additionally, temperature of the prisms is measured every day in order to control the material maturation process. The material is ready for sieving after 4-6 weeks. Following the process, the product – in order to makes the structure uniform and eliminate non- composted fractions – is sieved on a mobile drum sieve with an aperture size of 20 mm, and then on a sieve with an aperture size of 10 mm. Non-composted fractions are neutralised by combustion in a plant of thermal treatment of non-hazardous and inert waste. The product obtained is put on the storage yard.
3. A soil conditioner as an effect for managing biodegradable waste REMONDIS Bydgoszcz Sp. z o.o. collects waste from households and institutions. Selectively collected green waste from the territory of individual communes is dispatched to composting plants. The study has been conducted on samples collected from two loads of selectively collected biodegradable material described by the parameters specified in Table 2. The first load was used by a certified IUNG laboratory in Puawy to perform tests in order to obtain a decision from the Ministry of Agriculture. The second sample, collected a year later, was utilised to confirm the results obtained previously.
Table 2. Data for the studied sample of biodegradable material
Material number 538 652
Weight after sieving [Mg] 64.4 98.20
Source: own work.
Start: mesophilic and thermophilic mycelium >65°C: main process; thermophilic bacteria <65°C: mixed populations (bacteria, actinomycetes and mycelia)
Corg reduction
Ammonia
Temperature
pH
weeks
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The aim of the conducted study was to obtain a soil conditioner that would have the parameters required to receive a positive decision of the Ministry of Agriculture. The collected green material was subjected to the R3 process, i.e. recycling/recovery of organic substances. The composting process was subdivided into two parts – the first one was intensive composting, and the second one was pile composting, i.e. compost maturation. The first stage was taking place in closed reactors. Each of the tunnels has had the following dimensions: 19.7 m – length, 6.7 m – width, 5.77 m – height. They can be characterised as independent structures, furnished with a system for aeration and collection of effluent water. Aeration is conducted with the use of blowers built into the floor. The system is operating in a recirculation mode, with a supply of fresh air. A volume of ca. 2,250 m3 of air is entered into each single tunnel in one hour. Air drained from the system interior is first channelled to a scrubber, to two independent biofilters, in order to eliminate odours and ammonia. A biofilter is a concrete structure filled with comminuted roots of coniferous and deciduous trees that act as a filter. Walls of the tunnels are fitted with a sprinkler system to circulate the water in a closed circuit and add make–up water on a current basis correspondingly to losses in the process. Another characteristic of the tunnels is their being equipped with monitoring systems. Each of the tunnels may operate independently of others, even in the event of a failure. The entire process is controlled via a computer, which is possible chiefly due to sensors testing and adjusting the conditions inside the plant. Collected results – oxygen content, water volume, temperature – may be monitored on a current basis (Table 3 and 4). Intensive composting was being conducted in closed reactors for about 16 days, in conditions of forced aeration and air purification in the biofilter. Table 3. Stages of intensive composting and their respective parameters
Stages Parameters
I II I II I II I II
H2O 3.47 3.60 5.38 5.50 9.99 10.20 30.88 31.00 Blowing
temperature [°C] 41.08 42.00 43.07 43.00 50.03 51.00 47.86 47.88
Exhaust temperature [°C]
O2 [%]
20.70 20.70 20.70 20.80 20.70 20.70 20.70 20.80
Stage duration [h] 6 6 12 12 12 12 150 150 Source: own work. Table 4. Stages of intensive composting and their respective parameters
Stages Parameters
H2O 0.00 0.00 0.00 0.00 31.86 35.20 0.00 0.00 Blowing
temperature [°C] 45.16 45.00 50.35 50.30 49.43 49.49 39.97 39.90
Exhaust temperature [°C]
O2 [%]
20.70 20.80 20.70 20.80 20.70 20.80 20.70 20.80
Stage duration [h] 3 3 3 3 210 210 48 48 Source: own work.
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Green waste is loaded into the tunnels and treated with suitable temperature and aeration; an appropriate volume of water is added. In the course of intensive composting, the material is treated with high temperature for 12 h, which makes the material hygienic. The material is being kept in the tunnels for 2 weeks; during this period, waste is mechanically moved to the second tunnel to intensify the process. Parameters for the process of primary composting and composting proper have been shown in Tables 3 and 4. The predominant factor determining the end of the process in tunnels is usually temperature, which, at the end of composting proper (cooling), amounts to approx. 40°C. The most visible effect of running through the stage of intensive composting is the decrease of biodegradable waste weight by about 35%. After this period, the material is moved to a roofed compost pile yard, where it is matured. The second stage of the composting process was taking place at the compost pile yard and lasted for 4 to 6 weeks; average process temperature was 46°C. Pile temperature was measured every day. The process of composting of the studied samples lasted for ca. 7 weeks. The compost thus obtained was sieved in order to purify it. For purification, a sieve with an aperture size of 20 mm is used so as to eliminate components that have not been ground in the course of preparing the material for the process and during the process. Subsequently, a sieve with an aperture size of 10 mm is used. The finished product obtained following this procedure was used to acquire a positive decision of the Ministry of Agriculture.
4. Fertilising properties of the soil conditioner A soil conditioner manufactured in the composting process can be marketed but trade on the market is subject to Polish legal regulations. According to national legislation, fertilisers manufactured in Poland that have been granted the approval of the Minister of Agriculture and Rural Development as well as fertilisers manufactured or marketed in a Member State or EFTA state can be marketed in Poland, provided that ‘legal provisions in such a state ensure protection of human and animal health, and environmental protection as well as their suitability for use’. In Poland, trade in fertilisers is regulated by:
− the Act on Fertilisers and Fertilising of 10 July 2007, − the Regulation of the Minister of Agriculture and Rural Development of 18 June 2008, − the Regulation of the Minister of Economy of 8 September 2010.
The fundamental assumption resulting from the above-mentioned regulations is that commercial fertilisers should be of the highest quality, i.e. so that they are not harmful to health and life of people, animal and to the environment. Numerous studies and opinions of individual institutes precede the receipt of a positive decision of the Ministry of Agriculture and Rural Development. The first stage of obtaining a positive decision of the Institute of Soil Science and Plant Cultivation involves taking samples by a certified sampler from the Plant Breeding and Acclimatisation Institute. It was 8 samples of compost 1 kg each. They were stamped and sealed. Furthermore, a sample taking report was issued. The material samples were sent to the laboratory of the Institute of Soil Science and Plant Cultivation of the Research Institute in Puawy. The purpose of this operation was to obtain a report on physicochemical tests, i.e. indicating the content of organic mass, heavy metals and specifying sanitary condition of the manufactured soil conditioner. Results of the quality tests, the level of microbiological and parasitological contamination are given in Tables 5, 6 and 7.
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Tested feature Value
dry mass content [%] 59.8±0.6
water content [%] 40.2±0.5
nitrogen content [%] 1.1±0.17
ammonium nitrogen content [%] <0.05
phosphorus content [%] 0.16±0.03
potassium content [%] 0.5±0.06
magnesium content [%] 0.15±0.02
calcium content [%] 1.52±0.19 Source: own work. Table 6. Contamination level
Tested feature Permissible Value [mg/kg]
chrome content 100 37.1±5.2
cadmium content 5 <1.0
mercury content 2 0.08 ± 0.01 Source: own work.
Table 7. Fertilising properties of the soil conditioner
Conversion results Conversion rate Value [%]
from sample
calcium oxide content 0.715 2.13 ± 0.26 Source: own work.
The tested samples met quality requirements set forth in the Regulation of the Minister of Agriculture and Rural Development…