title: Leaching of heavy metals and alkylphenolic compounds from fresh and dried sewage sludge.
abstract: Reusing sewage sludge as a soil fertiliser has become a common alternative to disposal. Although this practice has a few benefits, it may contribute to the medium- and long-term contamination of the trophic chain because sewage sludge may contain heavy metals and organic contaminants. As the leaching of contaminants may depend on the sludge pre-treatment, the leaching of heavy metals (Cu, Ni, Pb, Zn and Cr) and alkylphenolic compounds (APCs) (octylphenol (OP), nonylphenol (NP), nonylphenol-mono-ethoxylate (NP1EO)) was investigated in five fresh and 40 °C dried sewage sludge samples from north-eastern Spain. FT-IR analyses and full-scan GC-MS chromatograms showed that sludge drying changed the nature of organic compounds leading to changes in their solubility. Moreover, sludge drying led to a higher relative contribution of dissolved organic carbon than the particulate organic carbon in the leachates. Leaching of Pb, Zn and Cr was below 5 % in both fresh and dried sludge samples, whereas Cu and Ni leached at rates up to 12 and 43 %, respectively, in some of the dried sludge samples. The leaching yields of OP, NP and NP1EO ranged from 1.3 to 35 % for fresh samples, but they decreased from 0.8 to 3.4 % in dried samples. The decrease in the leachability of APCs observed in dried sludge samples might be attributed to the fact that these compounds are associated with particulate organic matter, with significantly lower concentration or even absent in dried sludge than in fresh sludge samples. Therefore, it is recommended to dry the sludge before its disposal.
authors.affiliation: Department of Analytical Chemistry, University of Barcelona, Martí i Franquès 1-11, 08028, Barcelona, Catalonia, Spain.
authors.forename: Jelena
authors.initials: J
authors.lastname: Milinovic
authors.affiliation: Department of Analytical Chemistry, University of Barcelona, Martí i Franquès 1-11, 08028, Barcelona, Catalonia, Spain.
authors.forename: Miquel
authors.initials: M
authors.lastname: Vidal
authors.affiliation: Department of Environmental Chemistry, IDAEA-CSIC, Jordi Girona 18-26, 08034, Barcelona, Catalonia, Spain.
authors.forename: Silvia
authors.initials: S
authors.lastname: Lacorte
authors.affiliation: Department of Analytical Chemistry, University of Barcelona, Martí i Franquès 1-11, 08028, Barcelona, Catalonia, Spain. annarigol@ub.edu.
authors.forename: Anna
authors.initials: A
authors.lastname: Rigol
mesh_terms: D019216:Metals, Heavy / Q000032:analysis*; D010636:Phenols / Q000032:analysis*; D012722:Sewage / Q000032:analysis / Q000737:chemistry*; D012987:Soil / Q000737:chemistry; D012989:Soil Pollutants / Q000032:analysis; D013030:Spain; D017550:Spectroscopy, Fourier Transform Infrared; D014865:Waste Disposal, Fluid; D014874:Water Pollutants, Chemical / Q000032:analysis*
chemical_list: D019216:Metals, Heavy; D010636:Phenols; D012722:Sewage; D012987:Soil; D012989:Soil Pollutants; D014874:Water Pollutants, Chemical
references.citation: Environ Sci Pollut Res Int. 2007 Jan;14 Suppl 1:53-60
references.pmid: 21959541
references.citation: Sci Total Environ. 2009 Jun 15;407(13):4157-67
references.pmid: 19362327
references.citation: Sci Total Environ. 2002 May 27;291(1-3):45-57
references.pmid: 12150442
references.citation: Water Res. 2002 Feb;36(4):982-8
references.pmid: 11848370
references.citation: J Hazard Mater. 2004 May 20;108(3):161-9
references.pmid: 15120869
references.citation: Chemosphere. 2005 Dec;61(11):1710-9
references.pmid: 15893793
references.citation: Environ Toxicol Chem. 2003 Feb;22(2):450-6
references.pmid: 12558179
references.citation: J Hazard Mater. 2007 Oct 22;149(2):399-407
references.pmid: 17498873
references.citation: Chem Rev. 1997 Dec 18;97(8):3247-3272
references.pmid: 11851490
references.citation: Water Res. 2008 Aug;42(14):3941-51
references.pmid: 18694585
references.citation: Regul Toxicol Pharmacol. 2004 Dec;40(3):227-51
references.pmid: 15546678
references.citation: J Agric Food Chem. 2004 Sep 8;52(18):5635-42
references.pmid: 15373404
references.citation: Environ Pollut. 2002;117(3):515-21
references.pmid: 11911533
references.citation: Environ Sci Technol. 2001 Dec 15;35(24):4798-804
references.pmid: 11775155
references.citation: Environ Pollut. 2009 Feb;157(2):698-703
references.pmid: 18824283
references.citation: Environ Pollut. 1993;80(3):265-71
references.pmid: 15091846
references.citation: Chemosphere. 2007 Sep;69(4):636-43
references.pmid: 17445864
references.citation: Anal Bioanal Chem. 2009 Jul;394(6):1525-33
references.pmid: 19305980
references.citation: Sci Total Environ. 2007 Aug 15;382(1):82-92
references.pmid: 17532025
references.citation: J Chromatogr A. 2005 Sep 30;1089(1-2):45-51
references.pmid: 16130770
references.citation: Sci Total Environ. 2010 Jan 1;408(3):563-70
references.pmid: 19896162
references.citation: Environ Int. 2001 Nov;27(5):373-80
references.pmid: 11757851
references.citation: Environ Sci Technol. 2004 Aug 15;38(16):4390-5
references.pmid: 15382869