Metal concentrations in lime stabilised, thermally dried and anaerobically digested sewage sludges.

Autor: Healy MG; Civil Engineering, National University of Ireland, Galway, Ireland., Fenton O; Teagasc Johnstown Castle Environment Research Centre, Co. Wexford, Ireland., Forrestal PJ; Teagasc Johnstown Castle Environment Research Centre, Co. Wexford, Ireland., Danaher M; Food Safety Department, Teagasc Food Research Centre, Ashtown, Dublin 15, Ireland., Brennan RB; Civil Engineering, National University of Ireland, Galway, Ireland., Morrison L; Earth and Ocean Sciences, School of Natural Sciences and Ryan Institute, National University of Ireland, Galway, Ireland. Electronic address: liam.morrison@nuigalway.ie.
Jazyk: angličtina
Zdroj: Waste management (New York, N.Y.) [Waste Manag] 2016 Feb; Vol. 48, pp. 404-408. Date of Electronic Publication: 2015 Nov 25.
DOI: 10.1016/j.wasman.2015.11.028
Abstrakt: Cognisant of the negative debate and public sentiment about the land application of treated sewage sludges ('biosolids'), it is important to characterise such wastes beyond current regulated parameters. Concerns may be warranted, as many priority metal pollutants may be present in biosolids. This study represents the first time that extensive use was made of a handheld X-ray fluorescence (XRF) analyser to characterise metals in sludges, having undergone treatment by thermal drying, lime stabilisation, or anaerobic digestion, in 16 wastewater treatment plants (WWTPs) in Ireland. The concentrations of metals, expressed as mgkg(-1) dry solids (DS), which are currently regulated in the European Union, ranged from 11 (cadmium, anaerobically digested (AD) biosolids) to 1273mgkg(-1) (zinc, AD biosolids), and with the exception of lead in one WWTP (which had a concentration of 3696mgkg(-1)), all metals were within EU regulatory limits. Two potentially hazardous metals, antimony (Sb) and tin (Sn), for which no legislation currently exists, were much higher than their baseline concentrations in soils (17-20mgSbkg(-1) and 23-55mgSnkg(-1)), meaning that potentially large amounts of these elements may be applied to the soil without regulation. This study recommends that the regulations governing the values for metal concentrations in sludges for reuse in agriculture are extended to include Sb and Sn.
(Copyright © 2015 Elsevier Ltd. All rights reserved.)
Databáze: MEDLINE
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