Production and management of biodegradable waste in Cyprus

Transcription

1 SEEP2010 Conference Proceedings, June 29 th July 2 nd, Bari, ITALY Production and management of biodegradable waste in Cyprus N. Kythreotou a, G. Florides b, S.A. Tassou a a School of Engineering and Design, Brunel University, Uxbridge, Middlesex, UB8 3PH, UK (nikoletta.kythreotou@brunel.ac.uk, savvas.tassou@brunel.ac.uk) b Department of Mechanical Engineering and Materials Science and Engineering, Cyprus University of Technology, 31 Arch. Kyprianou, P. O. Box 50329, 3603 Lemesos, Cyprus (georgios.florides@cut.ac.cy) Abstract: This paper presents estimations for biodegradable waste generation in Cyprus and provides an overview of the methods currently used for of this waste. The quantities of the biodegradable fraction of municipal solid waste have been estimated at 215,460 tonnes (0.26 t/capita/year), sewage sludge 5,906 tonnes (7.13 kg/cap/year), sludge from food and drinks industries 957,050 tonnes, agricultural residues 109,440 tonnes, used cooking oils 4,000 tonnes (4.83 kg/capita/year) and livestock breeding waste 1,745,260 tonnes, giving the total biodegradable waste production for 2007 as 3,203,076 tonnes. Pig waste makes the largest contribution at 49%. The generation of biodegradable waste is mainly concentrated in three areas where there are large numbers of livestock farms and food and drink industries. These three areas account for 24% of the total biodegradable waste generated in Cyprus. The most commonly used method for waste in small installations is mechanical separation, while large installations are currently turning to anaerobic digestion. The biodegradable fraction of municipal solid waste is currently landfilled, while sewage sludge is mainly used as fertiliser. Keywords: biodegradable waste, animal waste, waste management, Cyprus, food and drink industrial waste 1. Introduction For the last few years, climate change and energy have been at the forefront of development strategies of the European Union. Among others, in December 2008, new targets were set for the 27 member states on the contribution of renewable energy to energy use as well as targets for reduction of greenhouse gas emissions from all sources. Cyprus does not have a long track record on dealing with environmental issues. The necessary legislation has only been in place for less than a decade. However, during the last 3 to 4 years, significant progress has been made in waste management which is slowly having an impact on everyday life. Being a relatively young country in terms of environmental policies and legislation, one of the first priorities has been the quantification of waste streams. This paper presents estimates on waste generation and outlines management practices and options for this waste. The need for data on biodegradable waste is triple; firstly, biodegradable waste can be used for the production of energy that contributes to the renewable energy target of the country, secondly, estimation of greenhouse gas emissions from waste and disposal enables the design and implementation of greenhouse reduction measures and thirdly enables establishment of the current status of waste management and assessment of the progress of implementation of the Landfill Directive [1] which requires biodegradable waste to be gradually eliminated from landfill. 2. Biodegradable waste in Cyprus Estimation of the biodegradable waste quantities for 2007 has been made using the generation coefficients proposed by Kythreotou et.al. [2] and Glekas et.al. [3]. In the case of the biodegradable fraction of municipal solid waste (MSW), sewage sludge and poultry waste, the average of the range proposed by Kythreotou et.al. [2] has been used. For the conversion of the generation coefficient of per sow quantities to per pig quantities, a ratio of 1 sow to 7 pigs has been used, while to convert the per dairy cow to per cow the ratio of 0.43 of dairy to total has been used. Where population was used as activity data for the estimations, tourists were also included in the total population. The only available estimate on total production of waste from the food and drinks industry is given by national statistics [4]. The results show that the largest contributor to biodegradable waste production in Cyprus is livestock breeding with 60% of the total. Of this, pig waste makes the largest contribution (48.9%) followed by poultry (6%) and cattle (5%). The food and drinks sector is the second largest contributor to biodegradable waste at 30% of the total. The percentage contribution of each waste stream to the total biodegradable waste generation is presented in Figure 1.

2 Figure 1. Contribution of waste streams to the total biodegradable waste in Cyprus for Spatial distribution of biodegradable waste in Cyprus The area under the effective control of the Republic of Cyprus is divided into five administration districts: Nicosia, Lemesos, Larnaca, Pafos and Ammochostos. The estimation of biodegradable waste production per district was based on the activity data and generation factors, with the exception of the food and drinks industry. For this sector, the waste generation estimates were based on the industrial activity per district, which was obtained from the Department of Environment [5]. These estimates proportion the total food and drinks industrial activity to 32% in Nicosia, 32% in Lemesos, 18% in Larnaca, 10% in Pafos and 8% in Ammochostos. On this basis, the waste generation per district has been estimated (Table 2). The contribution of each waste sector to total waste generation varies according to the activities in each district (Figure 2). Because of its relatively large population, industrial and livestock breeding activities, the Nicosia district makes the largest contribution (48%) to biodegradable waste in the country. Livestock waste makes the greatest contribution (73.7%) to the total biodegradable waste of the district. Larnaca makes the second largest contribution to the biodegradable waste in the island, 24%, even though it has almost half the population of Lemesos and smaller industrial activity. The relatively large contribution of Larnaca is due to its large livestock breeding activity, which contributes 72.2% of the total biodegradable waste of the district. Pafos, a coastal mountainous area has large areas of vineyards and other agricultural activities and small activity in livestock breeding. The area has a large number of wineries and waste from these constitutes the largest proportion of biodegradable waste followed by agricultural residues and livestock breeding. Lemesos has similar economic activities as Pafos, but with a wider variety of food and drink industries in addition to wineries. It also has the second largest population after Nicosia. For Lemesos most of the biodegradable waste arises from the food and drinks sector followed by livestock waste and MSW waste. Waste stream Generation coefficient Waste generation 2007 (t) Biodegradable fraction of MSW 0.26 t/cap 215,460 Sewage Sludge 7.13 kg/cap 5,909 Food & drink industries 957,050 Agricultural residues 109,440 - olive trees t/dec 35,814 - fruit bearing trees t/dec 18,228 - citrus trees t/dec 14,674 - vines t/dec 40,724 Used cooking oils 4.83 kg/cap 4,000 Livestock breeding 1,911,218 - Pigs 3.36 t/pig 1,565,138 - Cattle 2.68 t/cow 149,656 - Poultry kg/bird 196,423 Total 3,203,076 Table 1. Generation coefficients used and production of biodegradable waste for Cyprus during 2007, by source

3 Nicosia (NIC), t Ammochostos (AMM), t The contribution of Ammochostos to the total biodegradable waste of the Island is very small at only 4%, with the food and drinks sector making the largest contribution followed by livestock waste. The contributions of the 5 districts to the major biodegradable waste streams of the island are detailed in Figure 3. Larnaca (LAR), t Lemesos (LEM), t Pafos (PAF), t TOTAL for 2007 (t) Biodegradable fraction of MSW 81,138 15,667 35,045 60,375 23, ,460 Sewage Sludge 2, , ,909 Food & drink industries 306,256 76, , ,256 95, ,050 Agricultural residues 14,566 1,349 4,930 39,141 49, ,440 Used cooking oils 1, , ,000 Livestock waste 1,134,113 42, , ,204 47,630 1,911,218 Pigs 964,034 18, , ,669 35,734 1,565,138 Cattle 50,370 14,157 75,529 8,484 1, ,656 Poultry 119,709 10,028 37,856 18,050 10, ,423 Total 1,539, , , , ,092 3,203,076 48% 4% 24% 17% 7% 100% Table 2. Biodegradable waste generation per district according to source for 2007 Figure 3. Percent contribution of each district to the total production of biodegradable waste of Cyprus, 2007 Figure 2. Percent contribution of each biodegradable waste generation per district according to source, 2007, where NIC is Nicosia, AMM is Ammochostos, LAR is Larnaca, LEM is Lemesos and PAF is Pafos Livestock breeding in the districts of Nicosia and Larnaca is concentrated in three areas: Aradippou, Orounta and Athienou. In addition to a large number of large livestock breeding installations, these areas also accommodate strong food and drinks industrial activities. These include dairy, juice and meat industries, slaughterhouses and olive mills. The total biodegradable waste in the three areas form livestock breeding and food and drinks manufacture represents approximately 25% of the total generation of biodegradable waste in Cyprus. Unfortunately, due to the concentrated activity the three areas are also particularly vulnerable to pollution and contamination.

4 4. Management of biodegradable waste in Cyprus Biodegradable wastes are characterized by high organic content, which makes them suitable for biological. Thermal is also suitable for biodegradable waste due its high energy content of between TJ/Gg for solid biomass and 27.4 TJ/Gg for other liquid biomass [6] (where 1 Gg = 1 kt). At present in Cyprus there is a growing interest in anaerobic digestion, especially by large pig farms. Anaerobic digestion followed by aerobic allows the limits set in the liquid disposal permit and the air emissions permits to be satisfied. It is estimated that at present there are fourteen anaerobic digesters installed of which nine are for the of pig waste, three for food waste, one for slaughterhouse waste and one for sewage sludge. Additionally, six more are planned for animal waste. The reason for the large interest in anaerobic digestion is that there are Government incentives for the production of energy from biomass. Figure 4 shows the contribution of anaerobic plants to the electricity production of Cyprus. It can be seen that this has increased from almost zero in December 2007 to 1884 MWh in January Regardless to this trend though, the management options applied for biodegradable waste produced vary according to the waste stream as described below. The options of and management used are summarized in Table 3. Figure 4. Electricity production going to the national distribution network by anaerobic digestion plants, MWh [7] Biodegradable fraction of municipal solid waste: at present, 80% of municipal solid waste is landfilled. The remaining 20% is recycled. All biodegradable waste is currently disposed in controlled and uncontrolled landfills. Biodegradable fraction of MSW Sewage Sludge Agricultural and forestry residues Used cooking oils Management/ end use Solid end use Liquid end use Landfills Soil improver, landfill, off-site Landfill, on-site burning Conversion to biofuels, off-site Food & drink industries Off site Irrigation Slaughterhouses Olive mills Mechanical separation Soil improver, Off site Soil improver, pomace refining, animal feed, fuel Irrigation, meat meal production, incineration, anaerobic Irrigation, evaporation lagoon, soil improver Dairy industries Landfills Off site Wineries Irrigation Animal feed, Soil improver, zivania Pigs Cattle Poultry Separator, Anaerobic/ aerobic Separator, AD Soil improver, landfill, offsite Soil improver, landfill, offsite Soil improver, landfill, offsite Irrigation, evaporation lagoon Irrigation, evaporation lagoon, off-site Irrigation, evaporation lagoon, off-site Table 3. Summary of waste management and used for biodegradable waste in Cyprus

5 Sewage Sludge: the majority is dried and used in agriculture as soil improver. A small fraction is used in anaerobic digesters and the remainder is incinerated. Agricultural residues: the majority of agricultural residues are sent to landfill whilst a small fraction is burnt on site in the fields even though this is prohibited by law since Used cooking oils: the majority of used cooking oils is disposed in the sewerage system, thus undergoing the same as any other urban wastewater in Cyprus. Most sewage plants in Cyprus use secondary (biological), while newly constructed plants employ tertiary. All the water produced by sewage is reused for irrigation, recharge of aquifers and recharge of rivers and streams. In some extreme cases treated water is also disposed in the sea. There are also two installations that use cooking oils for the production of biodiesel. Food & drink industries: - Wastes from slaughterhouses are either treated at off-site plant for industrial waste or are biologically treated on site. - Olive mills: the majority of olive mills have mechanical separation equipment installed. The separated liquid is sent to evaporation tanks or irrigation, while the solid fraction is used as feedstock, or production of energy or soil improver. Some olive mills use off-site plant for the of industrial waste. - Dairy industries: most dairy installations transfer their waste to off-site plant for the of industrial waste. Some small, family size installations discharge their waste into the sewerage system whereas one of the largest industries has installed an anaerobic digester. - Wineries: most wineries use their liquid waste for irrigation, while the solid fraction is used as feedstock, soil improver or for the production of a local alcoholic beverage, zivania. Livestock waste - Pig and cattle farms: most small-scale installations use evaporation lagoons for the of their waste. The rest employ mechanical separation equipment. The separated liquid is sent to evaporation tanks or is used for irrigation, while the solid fraction is used as soil improver. Nine large pig farms have installed a combination of anaerobic / aerobic plant. The treated liquid fraction is used for irrigation or washing/cleaning or placed in evaporation tanks. - Poultry: Poultry waste which is almost dry, is left to dry and then used as soil improver. The main off-site installation used for the of waste is located in Vathia Gonia. It is a public installation managed by a private company on contract and has a capacity of 2,200 m 3 /day. The treated effluent is used for agricultural purposes in the same area. Figure 5 presents a schematic of the processes in the plant including the wastes that can be treated. Considering that animal waste makes the highest contribution to biodegradable waste production in Cyprus and the many environmental and health issues associated with insufficient waste management, the Department of Environment has issued a number of guidelines for the of particular animal waste streams [9,10,11]. In addition to the description of obligations of the owner of the animal farm, guidelines are given on how the waste should be managed. The proposed management approaches for pig, cattle and Figure 5. Process block diagram of Vathia Gonia plant [8]

6 poultry waste are presented in Figures 6, 7 and 8 respectively. Figure 6. Guidelines for the of pig waste according to final use of end product [9] Figure 8. Guidelines for the of solid and liquid waste from poultry farms [11] Any type of liquid waste should be treated sufficiently before disposal or re-use. The qualitative standards for treated liquid and solid fraction vary according to the end-use, which in turn decides the required. Agricultural waste and the biodegradable fraction of MSW should not be disposed to landfill. However, disposal to landfill is the approach currently used as there are no plants to treat this particular waste stream. (a) free stall housing (b) tie-stall housing Figure 3. Guidelines for the of cattle waste [10] 5. Potential of utilisation of biodegradable waste for production of energy As previously mentioned, there is an opportunity for biodegradable waste to be used for the production of energy by two methods, anaerobic digestion and thermal. The energy content that can be obtained from a particular type of waste varies considerably according to the used and whether any pre- takes place. Using the default coefficients for net calorific values proposed by the IPCC [6] of 15.6 TJ/Gg for agricultural waste, 27.4 TJ/Gg for liquid biomass and 11.6 TJ/Gg for other solid biomass and the biomass fraction of MSW, the theoretical potential of direct utilisation of the total production of biodegradable waste for the production of energy in Cyprus has been estimated at 57,582 TJ or 15,995 GWh (Table 4). The total energy demand of Cyprus in 2008 was 4,564.3 GWh [12]. This is almost a third of the energy that can be theoretically produced by biodegradable biomass to energy conversion.

7 Even if a small amount of waste (for example 10%) is utilised for energy production at low process efficiency (for example 25%) a significant amount of energy could be produced, 400 GWh, which is approximately 8% of the total consumption of the country. Currently, 8 livestock farms with anaerobic digesters feed to the national grid 1.9 GWh of electrical energy [7]. Waste quantity (Gg) Calorific value (TJ/Gg) [6] Potential energy production (TJ) Biodegradable fraction of MSW ,499 Sewage Sludge Food & drink industries ,662 Agricultural residues ,707 Used cooking oils Livestock waste 34,535 Pigs ,520 Cattle ,736 Poultry ,279 Total 57,582 Table 4. Potential for energy production from biodegradable waste in Cyprus 6. Conclusions Using reliable figures from 2007, the total biodegradable waste production in Cyprus has been estimated to be 3,198,440 tonnes. The largest contributor to this waste was 49% from pig farming and the second largest 30% from the food and drinks industry. Current management approaches for biodegradable waste could be improved considerably. Even though appropriate management is encouraged by the authorities and environmental behaviour is gradually improving, progress is rather slow. One example is composting plants which were planned to be in operation in 2007 but have not happened yet. Where progress is being made is in the utilisation of biodegradable waste from livestock farms to generate electricity using gas from anaerobic digestion. Biodegradable waste production on the island is concentrated in a small number of areas and this provides opportunities for the development of privately or publicly owned centralised waste management centres for effective management of this waste. References [1] European Council (1999). Council Directive 1999/31/EC of 26 April 1999 on the landfill of waste. Official Journal L 182, 16/07/1999 P [2] Kythreotou N., Florides G., Tassou A.S. (2010). The production of biodegradable waste in Cyprus. Accepted in Waste Management. Scheduled to be published in issue 30/7. [3] Personal communication with Dr. Ioannis Glekas, Aeoliki Ltd (2010). Nicosia, Cyprus. [4] Statistical Service (2006). Generation of waste, by waste type Ministry of Finance, Cyprus. [5] Personal communication with Mr. Neoklis Antoniou and Mr. Antis Athansiades, Department of Environment (2010). Nicosia, Cyprus. [6] Intergovernmental Panel on Climate Change (IPCC) (2006) IPCC Guidelines for National Greenhouse Gas Inventories. Prepared by the National Greenhouse Gas Inventories Programme, Eggleston H.S., Buendia L., Miwa K., Ngara T. and Tanabe K. (eds). Published: IGES, Japan. [7] Cyprus Energy Regulator Authority (2010). Electricity produced by biomass/ biogas systems connected to the system of Electricity Authority of Cyprus December 2007 January [8] Water Development Department (2000). The central wastewater plant at Vathia Gonia. Ministry of Agriculture, Natural Resources and Environment [9] Department of Environment (2008) Guidelines for small and large pig farms. Ministry of Agriculture, Natural Resources and Environment [10] Department of Environment (2007) Environmental issues associated with cattle farming. Ministry of Agriculture, Natural Resources and Environment [11] Department of Environment (2008) Guidelines for small and large poultry farms. Ministry of Agriculture, Natural Resources and Environment [12] Statistical Service (2009). Industrial Statistics Industrial Statistics, Series II, Report no. 45. Ministry of Finance, Cyprus.