Biological removal of organics and nitrogen from landfill leachates - A review

International Workshop on Management of Pollutant Emission from Landfills and Sludge

Volumn , Issue , 2008, Pages 187-203

  Klimiuk, Ewa ^a   Kulikowska, Dorota ^a   Koc Jurczyk, Justyna ^b  

^a UNIVERSITY OF WARMIA AND MAZURY IN OLSZTYN   (Poland)

^b UNIVERSITY OF RZESZÓW   (Poland)

Author keywords

Hazardous compounds; Landfill leachate composition; Organics and nitrogen removal

Indexed keywords

AROMATIC HYDROCARBONS; BIOLOGICAL SYSTEMS; DENITRIFICATION; LEACHATE TREATMENT; LEACHING; NITROGEN; NITROGEN REMOVAL;

BIOLOGICAL REMOVALS; EX-SITU; HAZARDOUS COMPOUNDS; IN-SITU; LANDFILL LEACHATE COMPOSITION; LANDFILL LEACHATES; LEACHATE; NITRIFICATION AND DENITRIFICATIONS; ORGANICS AND NITROGEN REMOVAL; ORGANICS REMOVALS; POLYAROMATIC HYDROCARBONS; TEMPORAL CHANGES;

REFUSE DISPOSAL;

EID: 60749125991     PISSN: None     EISSN: None     Source Type: Conference Proceeding    
DOI: None     Document Type: Conference Paper

References (123)

1. Ahnert, L. & Ehrig, H-J. 1992. Co-treatment of leachate with sewage. In Christensen, T.H., Cossu R. & Stegman, R. (eds.), Landfilling of waste: leachate: 403-116. Elsevier Applied Science London and New York.
2. Albers, H. & Krückeberg, G. 1992. Combination of aerobic pre-treatment, carbon adsorption and coagulation. In Christensen, T.H., Cossu, R. & Stegman, R. (eds.), Landfilling of waste: leachate: 305-312. Elsevier Applied Science London and New York.
3. Amokrane, A., Cornel, C. & Veron, J. 1997. Landfill leachates pretreatment by coagulation - flocculation. Water Research 31(11): 2775-2782.
4. Andreottola, G. & Carinas, P. 1992. Chemical and biological characteristics of landfill leachate. In Christensen,T.H., Cossu R. & Stegman, R. (eds.), Landfilling of waste:leachate 65-88. Elsevier Applied Science London and New York.
5. Avezzu, F., Bissolotti, G. & Collivignarelli, C. 1992. Combination of wet oxidation and activated sludge treatment. In:Christensen T.H., Cossu R., Stegman R (Eds.), Landfilling of waste: leachate. In Christensen, T. H., Cossu R. & Stegman, R. (eds.), Landfilling of waste: leachate 333-343. Elsevier Applied Science London and New York.
6. Bauer, M.J., Herrman, R., Martin A. & Zellman, H. 1998. Chemodynamics, transport behaviour and treatment of phthalic acid esters in minicipal landfill leachates. Water Science Technology 38(2): 185-192.
7. Baun, A. Reitzel, L.A., Ledin, A., Christensen, T.H. & Bjerg, PL. 2003. Natural attenuation of xenobiotic organic compounds in a landfill leachate plume (Vejen, Denmark). Journal of Contaminant Hydrology 65(2-3): 269-291.
8. Baun, A., Ledin, A., Reitzel, L.A., Bjerg, RL. & Christensen, T.H. 2004. Xenobiotic organic compounds in leachates from ten Danish MSW landfills - chemical analysis and toxicity tests. Water Research 38(18): 3845-3858.
9. Bengtsson, L., Bendz, D., Hogland, W., Rosqvist, H. & Akesson, M. 1994. Water balance for landfills of different age. Journal of Hydrology 158(3-4): 203-217.
10. Benson, C. H., Barlaz, M.A., Lane, D.T. & Rawe, J.M. 2007. Practice review of five bioreactor/recirculation landfills. Waste Management 21(1): 13-29.
11. Berge, N., Reinhart, D., Dietz, J. & Townsend, T. 2006. In situ ammonia removal in bioreactor landfill leachate. Waste Management 26(4): 334-343.
12. Bergs, C.G. & Lindner, K.H. 1997. Sewage sludge use in the Federal Republic of Germany. European Water Pollution Control 7(2): 47-52.
13. Bień, J.B. 2002. Sewage sludge. Theory and practice. Wydawnictwo Politechniki Czȩstochowskiej, Czȩstochowa (in Polish).
14. Bila, D.M., Montavão, A.F., Silva, A.C. & Dezotti, M. 2005. Ozonation of a landfill leachate: evaluation of toxicity removal and biodegradability improvement. Journal of Hazardous Materials Bl17: 235-242.
15. Bilstad, T. & Madland, M.V 1992. Leachate minimization by reverse osmosis. Water Science and Technology 25(3): 117-120.
16. Blakey, N.C. 1989. Model prediction of landfill leachate production. In: Christensen, T.H., Cossu, R., Stegmann R. (eds.), Sanitary landfilling: processes: 17-34. Technology and Environmental Impact. San Diego: Academic Press.
17. Blakey, N.C., Cossu, R., Maris, P.J. & Mosey, EE. 1992. Anaerobic lagoons and UASB reactors: laboratory experiments. In Christensen, T.H., Cossu, R. & Stegman, R. (eds.), Landfilling of waste: leachate: 203-210. Applied Science London and New York.
18. Borzacconi, L., Ottonello, G., Castelló, Palaez H., Gazzola, A. & Viñas, M. 1999. Denitrif ication in a carbon and nitrogen removal system for leachate treatment: performance of a upflow sludge blanket (USB) reactor. Water Science and Technology 40(8): 145-151.
19. Boyle, W.C. & Ham, R.K., 1974. Biological treatability of landfill leachate. Journal WPCF 46(5): 860-872.
20. Bull, P.S., Evans, J.V, Wechsler, R.M. & Cleland, K.J. 1983. Biological technology of the treatment of leachate from sanitary landfills. Water Research 17(11): 1473-1481.
21. Buniak, W, Jagiełło - Rymaszewska, E. & Szymańska -Pulikowska, A. 1997. PAHs and heavy metals content in municipal landfill leachate. V Scientific Technical Conference "Municipal waste management". Koszalin -Kołobrzeg, 189-197 (in Polish).
22. Burrows, W.D. & Rowe, R.S. 1975. Ether soluble constituents of landfill leachate. Journal WPCF 47(5): 921-923.
23. Calace, N., Liberatori, A., Petronio, B.M. & Pietroletti, M. 2001. Characteristics of different molecular weight fractions of organic matter in landfill leachate and their role in soil sorption of heavy metals. Environmental Pollution 113(3): 331-339.
24. Calli, B., Mertoglu, B. & Inane, B. 2005. Landfill leachate management in Istambul: applications and alternatives. Chemosphere 59(6): 819-829.
25. Carley, B.N. & Mavinic, D.S. 1991. The effects of external carbon loading on nitrification and denitrification of a high-ammonia landfill leachate. Research Journal of the Water Pollution Control Federation 63(1): 51-59.
26. Chan, G.Y.S., Chu, L.M. & Wong, M.H. 2002. Effects of leachate recirculation on biogas production from landfill co-disposal of municipal solid waste, sewage sludge and marine sediment. Environmental Pollution, 118(3):393-399.
27. Chang, J-E. 1989. Treatment of landfill leachate with an upflow anaerobic reactor combining a sludge bed and a filter. Water Science and Technology 21: 133-143.
28. Chen, P.H. 1996. Assessment of leachates from sanitary landfills: impact of age, rainfall and treatment. Environmental International 22: 225-237.
29. Chen, S. & Liu, J. 2006. Landfill leachate treatment by MBR: performance and molecular weight distribution of organic contaminant. Chinese Science Bulletin 51(23):2831-2838.
30. Chian, E.S.K. 1977. Stability of organic matter in landfill leachates. Water Research 11(2): 225-232.
31. Chianese, A., Ranauro, R. & Verdone, N. 1999. Treatment of landfill leachate by reverse osmosis. Water Research 33(3): 647-652.
32. Chiang, L-Ch. Chang, J-E. & Wen, T-Ch. 1995. Indirect oxidation effect in electrochemical oxidation treatment of landfill leachate. Water Research 29(2): 671-678.
33. Christensen, T.H., Kjeldsen, P., Bjerg, P.L., Jensen, D.L., Christensen, J.B., Baun, A., Albrechtsen, H-J. & Heron G. 2001. Biogeochemistry of landfill leachate plum. Applied Geochemistry 16(7-8): 659-718.
34. Cook, E.N. & Foree, E.G. 1974. Aerobic biostabilization of sanitary landfill leachate. Journal WPCF 46(2): 380-392.
35. Davis, R.D. & Hall, J.E. 1997. Production, treatment and disposal of wastewater sludge in Europe from a UK perspective. European Water Pollution Control 7(2): 9-17.
36. Doyle, J., Watts, S., Solley, D. & Keller, J. 2001. Exceptionally high - rate nitrification in sequencing batch reactors treating high ammonia landfill leachate. Water Science and Technology 43(3): 315-322.
37. Drzewicki, A., 2003. Biocenosis of activated sludge during municipal landfill leachate treatment in SBR reactors. Doctoral thesis, Faculty of Environmental Management and Agriculture, University of Warmia and Mazury in Olsztyn (in Polish).
38. Ehrig, H.J. 1989. Leachate quality. In: Christensen, T. H., Cossu R., Stegman, R., (eds), Sanitary landfilling: Process, technology and environmental impact: 213-230. London: Academic Press.
39. Ehrig, H.J. & Stegmann, R., 1992. Biological processes. In Christensen, T.H., Cossu R. & Stegman, R. (eds.), Landfilling of waste: leachate: 185-202. Elsevier Applied Science London and New York.
40. El-Fadel, M., Bou-Zeid, E., Chahine, W. & Alayli, B. 2002. Temporal variation of leachate quality from pre-sorted and baled municipal solid waste with high organic and moisture content. Waste Management 22: 269-282.
41. Fan, H-J., Shu, H-Y., Yang, H-S. & Chen, W-Ch. 2006. Characteristics of landfill leachates in central Taiwan. Science of the Total Environment 361(1-3): 25-37.
42. Farquhar, G. J. 1989. Leachate: production and characterization. Canadian Journal of Civil Engineering 16: 317-325.
43. Gourdon, R., Cornel, C., Vermande, P. & Veron, J. 1989. Fractionation of the organic matter of a landfill leachate before and after aerobic or anaerobic biological treatment. Water Research 23(2): 167-173.
44. Hao, X-D. & van Loosdrecht, M.C.M. 2004. Model-based evaluation of COD influence on a partial nitrification-Anammox biofilm (CANON) process. Water Science and Technology 49(11-12): 83-90.
45. Harkov, R., Gianti, S. J., Bozelli, J. W. & LaRegina, J. E. 1985. Monitoring volatile organic compounds at hazardous and sanitary landfills in New Jersey. Journal of Environmental Science and Health A20: 491-501.
46. Harmsen, J. 1983. Identification of organic compounds in leachate from a waste tip. Water Research 17(6):699-705.
47. He, R. & Shen, D-S. 2006. Nitrogen removal in the bioreac-tor landfill system with intermittent aeration at the top of landfilled waste. Journal of Hazardous Materials B136: 784-790.
48. Hellinga, C., Schellen, A.A.J.C., Mulder, J.W., van Loosdrecht, M.C.M. & Heijnen, J.J. 1998. The Sharon process: an innovative method for nitrogen removal from ammonium-rich wastewater. Water Science and Technology 37(9): 135-142.
49. Henry, J. G., Prasad, D. &Young, H. 1987. Removal of organ-ics from leachates by anaerobic filter. Water Research 21(11): 1395-1399.
50. Heyer, K.U. & Stegmann, R. 2005. Landfill systems, sanitary landfilling of solid wastes, and long-term problems with leachate. In: Environmental Biotechnology. Concepts and applications. Edited by Jördening, Winter. Wiley-VCH Verlag GmbH&Co. KGaA, Weinheim.
51. Im, J-H., Woo, H-X, Choi, M-W., Han, K-B. & Kim, Ch-W. 2001. Simultaneous organic and nitrogen removal from municipal landfill leachate using an anaerobic-aerobic system. Water Research 35(10): 2403-2410.
52. Imai, A., Onuca, K., Inamori,Y. & Sudo, R. 1995. Biodegra-dation and adsorption in refractory leachate treatment by the biological activated carbon fluidized bed process. Water Research 29(2): 687-694.
53. Jokela, J.P.Y., Kettunen, R. H., Sormunen, K.M. & Rintala, J.A. 2002. Biological nitrogen removal from municipal landfill leachate: low-cost nitrification in biofilters and laboratory scale in-situ denitrification. Water Research 36(16): 4079-4087.
54. Jokela, J. P. Y. & Rintala, J. A. 2003. Anaerobic solubilisation of nitrogen from municipal solid waste (MSW). Reviews in Environmental Science and Biotechnology 2(1): 67-77.
55. Jonsson, S., Ejlertsson, J., Ledin, A., Merisowsky, I. & Svens-son, B. H. 2003. Mono- and diesters from o-phthalic acid in leachates from different European landfills. Water Research 37(3): 609-617.
56. Kaczorek, K. & Ledakowicz, S. 2002. Deamonification of landfill leachate on peat bed. Inżynieria i aparatura chemiczna 3: 65-66 (in Polish).
57. Kaczorek, K., Sójka-Ledakowicz, J. & Ledakowicz, S. 2002. Comparison of biological methods and membrane techniques effectiveness in landfill leachate treatment. Inżynieria i aparatura chemiczna 3: 67-68 (in Polish).
58. Kang, K-H., Shin, H.S. & Park, H. 2002. Characterization of humic substances present in landfill leachates with different landfill ages and its implications. Water Research 36(16): 4023-1032.
59. Kennedy, K. J., Hamoda, M. F. & Guiot, S. G. 1988. Anaerobic treatment of leachate using fixed film and sludge bed systems. Journal WPCF 60(9): 1675-1683.
60. Kennedy, K. J. & Lentz, E. M. 2000. Treatment of landfill leachate using sequencing batch and continuous flow upflow anaerobic sludge blanket (UASB) reactors. Water Research 34(14): 3640-3656.
61. Kettunen, R.H. & Rintala, J.A. 1998. Performance of an on-site UASB reactor treating leachate at low temperature. Water Research 32(3): 537-546.
62. Khin, T. & Annachharte, A. P. 2004. Novel microbial nitrogen removal processes. Biotechnology Advances 22: 519-532.
63. Kim, S-M., Geissen, S-U. & Vogelpohl, A. 1997. Landfill leachate treatment by a photoassisted Fenton reaction. Water Science and Technology 35(4): 239-248.
64. Klimiuk, E. & Kulikowska, D. 2004. Effectiveness of organics and nitrogen removal from municipal landfill leachate in single and two-stage SBR system. Polish Journal of Environmental Studies 13(5): 517-527.
65. Klimiuk, E. & Kulikowska, D. 2005. The influence of operational conditions in sequencing batch reactors on removal of nitrogen and organics from municipal landfill leachate. Waste Management and Research 23: 429-438.
66. Klimiuk, E. & Kulikowska, D. 2006. Organics removal from landfill leachate and activated sludge production in SBR reactors. Waste Management 26: 1140-1147.
67. Kjeldsen, P., Barlaz, M.A., Rooker, A.P., Baun, A., Ledin, A. & Christensen, T.H. 2002. Present and long-term composition of MSW landfill leachate: a review. Critical Reviews in Environmental Science and Technology 32: 297-336.
68. Knox, K. 1985. Leachate treatment with nitrification of ammonia. Water Research 19(7): 895-904.
69. Koc-Jurczyk, J. 2006. Effectiveness of leachate treatment from old landfills using activated sludge system and deep oxidation. Doctoral thesis, Faculty of Environmental Management and Agriculture, University of Warmia and Mazury in Olsztyn (in Polish).
70. Kulikowska, D. 2002. Efficiency of municipal landfill leachate treatment in SBR. Doctoral thesis. Faculty of Environmental Engineering, Warsaw University of Technology (in Polish).
71. Kulikowska, D. & Klimiuk, E. 2004. Removal of organics and nitrogen from municipal landfill leachate in two-stage SBR reactors. Polish Journal of Environmental Studies 13(4): 389-396.
72. Kurniawa, T.A., Lo, W-H. & Chan, G.Y.S. 2006. Degradation of recalcitrant compounds from stabilized landfill leachate using a combination of ozone-GAC adsorption treatment. Journal of Hazardous Materials B137: 433-155.
73. Leitzke, O. 1996. Landfill leachate treatment by wet photochemical oxidation. Roczniki PZH 47: 125-134 (in Polish).
74. Laitinen, N., Luonsi, A. & Vilen, J. 2006. Landfill leachate treatment with sequencing batch reactor and membrane bioreactor. Desalination 191(1-3): 86-91.
75. Lema, J.M., Mendez, R. & Blazquez, R. 1988. Characteristics of landfill leachates and alternatives for their treatment: a review. Water, Air and Soil Pollution 40(3-4): 223-250.
76. Lo, I. 1996. Characteristics and treatment of leachates from domestic landfills. Environment International 22(4): 433-442.
77. Loukidou, M. X. & Zouboulis, A.I. 2001. Comparison of two biological treatment process using attached - growth biomass for sanitary landfill leachate treatment. Environmental Pollution 111(2): 273-281.
78. Madoni, P. 1994. A Sludge Biotic Index (SBI) for the evaluation of the biological performance of activated sludge plants based on the microfauna analysis. Water Research 28(1): 67-75.
79. Martienssen, M. & Schöps, R. 1997. Biological treatment of leachate from solid waste landfill sites - alterations in the bacterial community during the denitrification process. Water Research 31(5): 1164-1170.
80. Martienssen, M., Schulze, R. & Simon, J. 1995. Capacities and limits of three different technologies for the biological treatment of leachate from solid waste landfill sites. Acta Biotechnologica 15(3): 269-276.
81. Marttinen, S.K., Kettunen, R.H. & Rintala, J.A. 2003. Occurrence and removal of organic pollutants in sewages and landfill leachates. Science of the Total Environment 301(1-3): 1-12.
82. Mertoglu, B., Calli, B., Inane, B. & Özturk, I. 2006. Evaluation of in situ ammonia removal in an aerated landfill biorector. Process Biochemistry 41(12): 2359-2366.
83. Monje-Ramirez, I. & Orta de Velásquez, M.T. 2004. Removal and transformation of recalcitrant organic matter from stabilized saline landfill leachates by coagulation-ozonation coupling processes. Water Research 38(9): 2358-2366.
84. Mulder, A., van de Graaf, A.A., Robertson L.A. & Kuenen J.G. 1995. Anaerobic ammonium oxidation discovered in a denitrifying fluidized bed reactor. FEMS Microbiology Ecology 16: 177-184.
85. Obrzut, L. 1997. Leachate from municipal landfills. Eko-profit 5: 32-36 (in Polish).
86. Paxéus, N. 2000. Organic compounds in municipal landfill leachates. Water Science and Technology 42(7-8): 323-333.
87. Ragle, N., Kissel, J, Ongerth, J.E. & DeWalle, F.B. 1995. Composition and variability of leachate from recent and aged areas within a municipal landfill. Water Environment Research 67(2): 239-243.
88. Reinhard, M., Goodman, N.L. & Barker, J.F. 1984. Occurrence and distribution of organic chemicals in two landfill leachate plumes. Environmental Science and Technology 18: 953-961.
89. Rivas, F. J., Beltrán, F., Gimeno, O., Acedo, B. & Carvalho, F. 2003. Stabilized leachates: ozone-activated carbon treatment and kinetics. Water Research 37(20): 4823-4834.
90. Robinson, H.D. & Grantham, G. 1988. The treatment of landfill leachates in on-site aerated lagoon plants: experience in Britain and Ireland. Water Research 22(6): 733-747.
91. Robinson, H.D. & Maris, P. J. 1983. The treatment of leachates from domestic wastes in landfills I. Aerobic biological treatment of a medium - strength leachate. Water Research 17(11): 1537-1548.
92. Rosik-Dulewska, Cz. 2005. Basics of waste management. Wydawnictwo Naukowe PWN, Warszawa (in Polish).
93. Sabel, G. V & Clark, T. P. 1984. Volatile organic compounds as indicators of municipal solid waste leachate contamination. Waste Management and Research 2: 119-130.
94. Schmidt, I., Sliekers, O., Schmidt, M., Bock, E., Fuerst, J., Kuenen, J.G., Jetten M.S.M. & Strous M. 2003. New concepts of microbial treatment processes for the nitrogen removal in wastewater. FEMS Microbiology Reviews 27: 481-192.
95. Schulz, B. & Kjeldsen, P. 1986. Screening of organic matter in leachates from sanitary landfills using gas chromatography combined with mass spectrometry. Water Research 20(8): 965-970.
96. Schwarzbauer, J., Heim, S., Brinker, S. & Littke, R. 2002. Occurrence and alteration of organic contaminants in seepage and leakage water from a waste deposit landfill. Water Research 36(9): 2275-2287.
97. Shiskowski, D.M. & Mavinic, D.S. 1998. Biological treatment of a high ammonia leachate: influence of external carbon during initial startup. Water Research 32(8): 2533-2541.
98. Skalmowski, K. 2001. Municipal waste composting. Models of technological solutions. Oficyna Wydawnicza Politech-niki Warszawskiej, Warszawa (in Polish).
99. Slack, R.J., Gronow, J.R. & Voulvoulis, N. 2005. Household hazardous waste in municipal landfills: contaminants in leachate. Science of the Total Environment 337(1-3): 119-137.
100. Sliekers, A.O., Derwort, N., Gomez, J.L.C., Strous, M., Kuenen, J.G. & Jetten M. S. M. 2002. Completely autotrophic nitrogen removal over nitrite in one single reactor. Water Research 36(10): 2475-2482.
101. Statom, R.A., Thyne, G.D. & McCray, J.E. 2004. Temporal changes in leachate chemistry of municipal solid waste landfill cell in Florida, USA. Environmental Geology 45(7), 982-991.
102. Steensen, M. 1997. Chemical oxidation for the treatment of leachate - process comparison and results from full-scale plants. Water Science and Technology 35(4): 249-256.
103. Surmacz-Górska, J., Miksch, K. & Kita, M. 2000. Opportunities of landfill leachate pretreatment using biological methods. Archiwum Ochrony Środowiska 26(3): 43-54 (in Polish).
104. Szpadt, R. 1995. Physics - chemical and microbiological risk of the environment due to waste. Biblioteka Monitoringu Srodowiska. Warszawa, 216-220 (in Polish).
105. Takai.T., Hirata, K., Yamauchi, K. & Inamori, Y. 1997. Effects of temperature and volatile fatty acids on nitrification-denitrification activity in small-scale anaerobic-aerobic recirculation biofilm process. Water Science and Technology 35(6): 101-108.
106. Tatsi, A.A. & Zouboulis, A.I. 2002. A field investigation of the quantity and quality of leachate from a municipal waste landfill in a Mediterranean climate (Thessa-loniki, Greece). Advances in Environmental Research, 6: 207-219.
107. Timur, H. & Özturk, I. 1997. Anaerobic treatment of leachate using sequencing batch reactor and hybrid bed filter. Water Science Technology 36(6-7): 501-508.
108. Timur, H. & Özturk, I. 1999. Anaerobic sequencing batch reactor treatment of landfill leachate. Water Research 33(15): 3225-3230.
109. Timur, H., Özturk, I., Altinbas, M., Arikan, O. & Tuyluoglu, B.S. 2000. Anaerobic treatability of leachate: a comparative evaluation for three different reactor systems. Water Science and Technology 42(1-2): 287-292.
110. Trebouet, D., Schlumpf, J.P., Jaouen, P. & Quemeneur, F. 2001. Stabilized landfill leachate treatment by combined physicochemical- nanofiltration processes. Water Research 35(12): 2935-2942.
111. van de Graaf, A.A., Mulder, A., de Bruijn, P., Jetten, M.S.M., Robertson, L.A. & uenen, J. G. 1995. Anaerobic oxidation of ammonium is biologically mediated process. Applied and Environmental Microbiology, 61(94): 1246-1251.
112. Vicevic, G.P., Top, P.J. & Laughlin, R.G.W. 1992. Aerobic and anaerobic fixed film biological reactors. In Christensen, T.H., Cossu R. & Stegman, R. (eds.), Landfilling of waste: leachate: 229-243. Elsevier Applied Science London and New York.
113. Warith, M.A., Zebry, W. & Gawri, N. 1999. Effect of leachate recirculation on municipal solid waste biodegra-dation. Water Quality Research Journal of Canada 34(2): 267-280.
114. Welander, U. & Henrysson, T. 1998. Degradation of organic compounds in a municipal landfill leachate treated in a suspended - carrier biofilm process. Water Environment Research 70(6): 1236-1241.
115. Welander, U., Henrysson, T. & Welander, T. 1997. Nitrification of landfill leachate using suspended-carrier biofilm technology. Water Research 31(9): 2351-2355.
116. Wentzel, A., Gahr, A. & Niessner, R. 1999. TOC-removal and degradation of pollutants in leachate using a thin-film photoreactor. Water Research 33(4): 937-946.
117. Wiszniowski, J., Surmacz-Górska, J. & Miksch, K. 2001. Application of immobilized biomass of activated sludge to landfill leachate treatment. VII Ogólnopolskie Sympozjum Naukowo-Techniczne "Biotechnologia Środowiskowa" 121-135 (in Polish).
118. Wu, J.J., Wu, Ch-Ch., Ma, H-W. & Chang, Ch-Ch. 2004. Treatment of landfill leachate by ozone-based advanced oxidation processes. Chemosphere 54: 997-1003.
119. Yamamoto, T., Yasuhara, A., Shiraishi, H. & Nakasugi, O. 2001. Bisphenol A in hazardous waste landfill leachates. Chemosphere 42: 415-418.
120. Yaqout, A F.A. 2003. Assessment and analysis of industrial liquid waste and sludge disposal at unlined landfill sites in arid climate. Waste Management 23: 817-824.
121. Yasuhara, A., Shiraishi, H., Nishikawa, M., Yamamoto, T., Uehiro, T. & Nakasugi, O. 1997. Determination of organic components in leachates from hazardous waste disposal sites in Japan by gas chromatography-mass spectrometry. Journal of Chromatography 774(1-2): 321-332.
122. Zaloum, R. & Abbott, M. 1997. Anaerobic pretreatment improves single sequencing batch reactor treatment of lanfill leachates. Water Science and Technology 35(1): 207-214.
123. Zamora, R.M.R., Moreno, A.D., Orta de Velasquez, M.T & Ramirez, I.M. 2000. Treatment of landfill leachates by comparing advanced oxidation and coagulation-flocculation processes coupled with activated carbon adsorption. Water Science and Technology 41(1): 231-235.