PNNL

Abstract

The degradation pathway of nonylphenol ethoxyacetic acid (NP1EC) and the conditions favoring CAP1EC formation were studied in aerobic microcosms constructed with soil from the Mesa soil aquifer treatment (SAT) facility (Arizona, USA) and pristine sediments from Coyote Creek (California, USA). In the Mesa microcosms, para-NP1EC was transformed to para-NP, before being rapidly transformed to nonyl alcohols via ipso-hydroxylation. While the formation of NP from APEMs has been observed by several researchers under anaerobic conditions, this is the first time the transient formation of NP from APEMs has been observed under aerobic conditions. Unlike the Mesa microcosms, large quantities of CAP1ECs were observed in the Coyote Creek microcosms. Initially, CA8P1ECs were the dominant metabolites, but as biodegradation continued, CA6P1ECs became the dominant metabolites. Compared to the CA8P1ECs, the number of CA6P1ECs peaks observed was small (