Pentachlorophenol and tetrachlorophenols in wadden sediment and clams Mya arenaria of the Jadebusen after a 14-year period of wastewater discharge containing pentachlorophenol

Abstract

Pentachlorophenol (PCP) and tetrachlorophenol (TCP) concentrations in anaerobic Wadden sediments and clams of the Jadebusen were determined two years after the end of a long-lasting discharge of PCP into the region. Concentrations of PCP were of the same order of magnitude as those determined in sediments and organisms of the Weser estuary; concentrations after acid hydrolysis were 2–5 times higher than those of free PCP. 2,3,4,5-TCP contents exceeded those of PCP eight times in sediments and fifteen times in clams. PCP and 2,3,4,5-TCP were accumulated in clams 100- to 1000-fold compared with sediments. It is assumed that, under anaerobic conditions, a reductive dechlorination of PCP occurs, resulting in 2,3,4,5-TCP, which is more persistent than PCP in the environment under study.