Dioxin-like compounds in Australian sewage sludge - Review and national survey

Bradley O Clarke, Nichola A Porter, Robert K Symons, Judy R Blackbeard, Peter K Ades, Philip Marriott

Research output: Contribution to journalArticleResearchpeer-review

35 Citations (Scopus)

Abstract

An Australian survey of dioxin-like compounds in sewage sludge was conducted in two parts (a) a national survey, and (b) a time-study. All sewage sludge samples analysed as part of these studies had low overall concentrations of dioxin-like compounds. Out of 37 samples, all except one, were within the reported concentration range of soil within the Australian environment. The mean concentration of dioxin-like compounds in the Australian sewage sludge survey of 2006 was found to be 5.6 (s.d. 4.5) ng WHO05 TEQ kga??1 (n = 14) and were within the range of 1.2a??15.3 ng WHO05 TEQ kga??1. All the Australian sewage sludge samples cited in these studies were below the Victorian EPA a??investigation limita?? of 50 ng WHO98 TEQ kga??1, and well below the European proposed guidelines of 100 ng I-TEQ kga??1. The burden of dioxin-like compounds in Australian sewage sludge is low and its land application as biosolids is not likely to pose a problem. A general positive relationship was found between population of the town producing the waste and both dioxin-like PCDD/Fs and dioxin-like PCBs. The one exception to this trend was sludge from a town that had a history of smelting and had a relatively high burden of dioxin-like compounds. Sludge from one rural WWTP also had a higher burden of dioxin-like compounds. The treatment plant services a geographically isolated town with a low population and no known emitters of dioxin-like compounds. However, this sample also had a relatively high burden of dioxin-like PCBs, which could be the source of the dioxin-like PCDD/Fs found in this sludge. The time study analyzing sludges from three WWTP from the same city between the years 2002 and 2006 found no apparent difference between WWTPs, but a statistically significant decline of 1.49 ng WHO05 TEQ kga??1 per year. Also, a comprehensive review of the scientific literature, presents typical levels and sources of dioxin-like compounds in international sewage sludges.
Original languageEnglish
Pages (from-to)1215 - 1228
Number of pages14
JournalChemosphere
Volume72
Issue number8
DOIs
Publication statusPublished - 2008
Externally publishedYes

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