In Estonian landfills, in addition to waste sorting and depositing, most biodegradable waste is composted. Stormwater and snowmelt samples collected from compost fields have shown a high content of pollutants. Furthermore, the flow rate of landfill wastewater can vary greatly. This has a significant influence on the options for and efficiency of treatment methods.
Different technologies for landfill wastewater treatment were tested, and the operation of several treatment plants was observed from 2007 to 2014. On the basis of the present research, the wastewater treatment system at Väätsa was redesigned and reconstructed. The treatment system consists of a landfill wastewater collection system, an equalizing tank, physical/chemical (i.e. reverse osmosis) treatment after biological activated sludge treatment and oxidation in pond, and stabilization of the pumping and distribution systems for concentrate discharge from reverse osmosis back to the landfill. Since April 2012, the parameters in the effluent from the treatment plant have been in compliance with the permitted limit values. The composting of biodegradable waste needs to cease for an efficient and stabilized treatment of landfill wastewater. Methane fermentation is considered to be the most effective method for biodegradable waste treatment, and it generates biogas as a by-product.
The rearrangement of composting and depositing of biodegradable waste in combination with anaerobic fermentation would facilitate the production of up to 23.1 million m3 of biomethane per year, which is equal to about 226 MWh heat and electric energy. The digestate that is produced during methane fermentation contains a significant amount of plant nutrients, which could be used for fertilizing certain cultivated areas.
1. Council Directive 1999/31/EC of 26 April 1999 on the landfill of waste. Official Journal, L182, 16/07/1999, 0001–0019.
2. European Union. Directive 2000/60/EC of the European Parliament and of the Council of 23 October 2000 establishing a framework for Community action in the field of water policy. Official Journal, L327, 22/12/2000, 0001–0073.
3. Veeseadus (Water Act). Riigi Teataja (State Gazette) RT I, 30.06.2015, 4 (in Estonian).
4. Sumanaweera, S. Advanced Treatment of Landfill Leachate. Advanced Oxidation Combined with a Membrane Bio-reactor for Landfill Leachate Treatment. VDM Verlag Dr. Müller, Saarbrücken, 2010.
5. Christensen, T. H. Solid Waste Technology & Management. Volume 1 and 2. Department of Environmental Engineering, Technical University of Denmark, Lyngby, Denmark. John Wiley and Sons, Ltd., 2010.
6. Guidance for the treatment of landfill leachate. In Integrated Pollution Prevention and Control. Environment Agency, Environment & Heritage Service, Scottish Environment Protection Agency, 2006.
7. Studies on landfill leachate and analyses of different treatment methods: Elaboration of a treatment methodology suitable for Estonian conditions. Tallinn Universiy of Technology, Department of Environmental Engineering. Project No. 100. Final Report. Tallinn, 2010, 9–211 (in Estonian).
8. Di Iaconi, C., Ramadori, R., and Lopez, A. Combined biological and chemical degradation for treating a mature municipal landfill leachate. Biochem. Eng. J., 2006. 31(2), 118–124.
9. Ried, A. and Mielcke, M. The state of development and operational experience gained with processing leachate with a combination of ozone and biological treatment. In Proceedings of the 14th Ozone World Congress. Dearborn, Michigan, USA, August 22–26, 1999. International Ozone Organization, 1999, Volume 2, 65–81.
10. Wang, L. K., Shammas, N. K., and Hung, Y.-T. (eds). Advanced Physicochemical Treatment Technologies. Volume 5. Handbook of Environmental Engineering. Humana Press, Totowa, New Jersey, 2007.
11. Wang, L. K., Hung, Y-T., and Shammas, N. K. (eds). Advanced Physicochemical Treatment Processes. Volume 4. Handbook of Environmental Engineering. Humana Press, Totowa, New Jersey, 2006.
12. Boyle, W. C. and Ham, R. K. Biological treatability of landfill leachate. J. Water Poll. Contr. Fed., 1974, 46, 860–867.
13. Kettunen, R. H. Treatment of Landfill Leachates by Low-Temperature Anaerobic and Sequential Anaerobic–Aerobic Process. Tampere University of Technology Publications. Tampere, 1997.
14. Baig, S., Thieblin, E., Zuliani, F., Jenny, R., and Coste, C. Landfill leachate treatment: case studies. In Proceedings of the International Conference on Ozonation and Related Oxidation Process in Water and Waste Treatment, 21–23 April 1997, Berlin, Germany. 1997, V.4.1/V.4.16.
15. Goi, A., Veressinina, Y., and Trapido, M. Combination of ozonation and Fenton processes for landfill leachate treatment: evaluation of treatment efficiency. In Proceedings of IOA International Conference on Ozone & Related Oxidants in Advanced Treatment of Water for Human Health and Environment Protection, 15–16 May 2008, Brussels, Belgium. 2008, 188.8.131.52–6.1.2–12.
16. Haapea, P., Korhonen, S., and Tuhkanen, T. Treatment of industrial landfill leachates by chemical and biological methods: ozonation, ozonation+hydrogen peroxide, hydrogen peroxide and biological post-treatment for ozonated water. Ozone–Sci. Eng., 2002, 24, 369–378.
17. Beaman, M. S., Lambert, S. D., Graham, N. J. D., and Anderson, R. Role of ozone and recirculation in the stabilization of landfills and leachates. Ozone–Sci. Eng., 1998, 20, 121–132.
18. Huang, S., Diyamandoglu, V., and Fillos, J. Ozonation of leachates from aged domestic landfills. Ozone–Sci. Eng., 1993, 15, 433–444.
19. Kamenev, I., Viiroja, A., and Kallas, J. Aerobic bio-oxidation with ozonation for recalcitrant wastewater treatment. J. Adv. Oxid. Technol., 2008, 11(2), 338–347.
20. Gottschalk, C., Libra, J. A., and Saupe, A. Ozonation of Water and Wastewater. Wiley-VCH, Weinheim, 2002.
21. Lopez, A., Pagano, M., Volpe, A., and Di Pinto, A. C. Fenton’s pre-treatment of mature landfill leachate. Chemosphere, 54, 1005–1010.
22. Gau, S.-H. and Chang, F.-S. Improved Fenton method to remove recalcitrant organics in landfill leachate. Water Sci. Tecnol., 34, 455–462.
23. Kuusik, A., Pachel, K., Kuusik, A., and Loigu, E. Landfill runoff water and landfill leachate discharge and treatment. In 9th International Conference Environmental Engineering, Water Engineering (1-8). Vilnius, Lithuania, 2014. VGTU Press “Technika”, 2014.
24. Kuusik, A., Pachel, K., Kuusik, A., Loigu, E., and Tang, W. Z. Reverse osmosis and nanofiltration of biologically treated leachate. Environ. Technol., 2014, 35, 2416–2426.
25. Wastewater treatment, wastewater and stormwater discharges, pollutant limit values and supervision measures on implementation. Order of the Government of the Republic of Estonia No. 99 from 29 November 2012, 1–6.
26. Preliminary project for reconstructing the wastewater treatment of Väätsa landfill. No. U – 2009 - 002. OÜ Vetepere, 2009, 1–25 (in Estonian).
27. Declarations of the water pollution charges in Väätsa landfill (in Estonian).
28. Wastewater treatment plant in AS Torma Landfill. Main project – explanatory letter and drawings. SWECO Eesti AS, No. 06036. Tallinn, 2009, 1–17 (in Estonian).
29. Tõnisberg, E. Lechate treatment in Torma landfill. Keskkonnatehnika, 2011, No. 11, 14–15 (in Estonian).
30. Declarations on the water pollution charges in Torma landfill (in Estonian).
31. National Waste Action Plan 2014–2020. Tallinn, 2014 (in Estonian).
32. Jäätmeseadus [Waste Act]. Riigi Teataja RT I, 23.03.2015, 204.
33. Handreichung. Biogasgewinnung und -nutzung. 3., überarbeitete Auflage. Gülzow, 2006.
34. Elaboration of the strategy for processing sediments from wastewater treatment, including safeguarding harmless recycling by applying efficient supervision, chemical and biological indicators and quality assurance systems. I, II and III stage. Estonian Environmental Research Centre, Tallinn, 2013 (in Estonian).
35. Applicability and environmental and economic impacts of technologies suitable in Estonian conditions for treating biogas into methane. Expanded summary. Tallinn University of Technology, Department of Heat Engineering, Tallinn, 2014, 3–28 (in Estonian).
36. Study on the possibilities of using stabilised and dried wastewater treatment sludge from Tallinn Wastewater Treatment Plant as well as cultivation soil processed from that in green areas, agriculture and recultivation or other sectors. OÜ Vetepere, Tallinn, 2003, 4–33 (in Estonian).
37. Pitk, P. Protein- and Lipid-rich Solid Slaughterhouse Waste Anaerobic Co-digestion: Resource Analysis and Process Optimization. Tallinn University of Technology, Department of Chemistry, Tallinn, 2014.
38. Manikandan, K. and Viruthagiri, T. Optimization of C/N ratio of the medium and fermentation conditions of ethanol production from tapioca starch using co-culture of Aspergillus niger and Sachormyces cerevisiae. International Journal of ChemTech Research, 2010, 2(2), 947–955.
39. Study on landfill water and different treatment technologies analysis: Elaboration of treatment technology suitable for Estonian situation. Treatment of Väätsa landfill wastewater. Tallinn University of Technology, Environmental Engineering Department. Project No. 100, III-I. Tallinn, 2009 (in Estonian).
40. Kuusik, A., Pachel, K., Kuusik A., and Loigu, E. Anaerobic co-digestion of sewage sludge with fish farming waste. In 9th International Conference Environmental Engineering; Water Engineering (1–8). Vilnius, VGTU Press “Technika”, 2014.
41. Kuusik, A., Kuusik, A., Pachel, K., Loigu, E., and Sokk, O. Generalised integration of solid waste treatment practices to enhance methane productivity, generate suspension fertiliser and upgrade biogas. European Scientific Journal, 2013, 9(36), 14–30.
42. Kuusik, A., Loigu, E., Kuusik, A., and Sokk, O. Possibility of enhancing methane productivity in anaerobic reactors in the treatment of excess sludge from wastewater treatment plants. International Journal of Science and Engineering Investigations, 2013, 2(12), 33–36.
43. Kuusik, A., Kuusik, A., Loigu, E., Sokk, O., and Pachel, K. Selection of most promising substrates for biogas production. Int. J. Energy Environ., 2013, 7(3), 115–124.
44. Kuusik, A., Kuusik, A., Loigu, E., and Sokk, O. Predicting preferable substrate blends for the production of biogas. In World Scientific and Engineering Academy and Society: Recent Advances in Environmental Science, Lemesis, Cyprus, 21–23 March 2013. WSEAS, 2013, 192–197.
45. Kuusik, A., Loigu, E., Sokk, O., and Kuusik, A. Enhancement of methane productivity of anaerobic reactors of wastewater treatment plants. In World Academy of Science, Engineering and Technology (Issue 65): WASET 2012 Tokyo, Japan International Conference, 29–30 May 2012. WASET, 2012, 1191–1193.
46. Pikka, J. and Kuusik, A. Concentration of nutrients in the assimilating organs of silver birch growing in alvar and peat substrates treated with different doses of sewage sludge. Presentation at the seminar held by the National Centre for Forest Management, Tallinn, 2010 (in Estonian).Kuusik A., Pikka J., and Pikka, M. Elaboration of methodology for experiments on reforestation and peatland renovation with the sludge from Tallinn municipal wastewater treatment by the Tallinn Water Utility. Report No. 6. OÜ Vetepere, Tallinn, 2007, 4–34 (in Estonian).