Environmental Engineering Reference
In-Depth Information
3.4
Dichlofluanid
Dichlofluanid has been detected in marine sediments in Greece [66, 78], the
UK [41] and Spain [79]. Levels in sediment have been reported as significantly
higher after the boating season than before, and after the boating season
dichlofluanid levels are significantly higher in marinas and mooring areas
than in coastal sites, indicating that antifouling paints on boats could be a ma-
jor source of this compound [76].
Dichlofluanid tends not to be found in waters; however, considerable con-
centrations of the biocide have been observed in sediments [41]. It is un-
stable in water [87], which may explain the absence of contamination of
water samples. However, it has been reported to have relatively high con-
centrations in sediments after the boating season, which may be due to
its very low solubility in water and the high octanol
water partition coef-
ficient. Dichlofluanid has a strong affinity for particulate material [88] and
exhibits the greatest tendency towards solid-phase partitioning when com-
pared with Irgarol, chlorothalonil and diuron, accounting for between 90 and
99% of dichlofluanid available [76]. However, it is susceptible to anaerobic
degradation and this may play an important role in its removal from the
environment [88].
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3.5
Sea-Nine 211/Kathon
Sea-Nine binds strongly to sediment, and once bound is essentially immo-
bile [89]. It has been detected in sediments in southeastern Spain [79], but its
detection has not been reported in other studies [66, 78]. This may be because
it degrades rapidly; it has a half-life in seawater of less than 1 hour [89].
3.6
TCMTB (Busan) and TCMS Pyridine (Densil 100)
Limited data are available on the sorption characteristics of TCMTB and it has
proved impractical to theorise on its behaviour [87]. Data on its presence in
marine sediments are also limited.
3.7
Zinc Pyrithione and Zineb
Along with dichlofluanid, zinc pyrithione and zineb are among the few re-
maining antifouling products that are permitted for amateur use in the
UK [35]. Despite this, few data exist on their occurrence in sediments, and
their partitioning behaviour has not been studied.
