Ingles El Bisfenol A Degradación En Agua De Mar Es Diferente De La Del Agua De Los Ríos

El bisfenol A degradación en agua de mar es diferente de la del agua de los ríos

Abstract

The purpose of this study was to identify a relationship between changes of bacterial counts and bisphenol A (BPA) degradation in seawater under aerobic or anaerobic conditions, and at temperatures of 4, 25, and 35 ºC. Water samples (seawater and river water) spiked with 1000 ng/ml of BPA was placedfor 60 d. The BPA from water samples was extracted by OASIS HLB cartridges and was detected by high-performance liquid chromatography with fluorescence detection. BPA in river water was degraded under aerobic conditions and was below a detection limit (0.5 ng/ml) on the seventh day at both 25 and 35 ºC. The more the level of bacterial counts increased, the more BPA degradation decreased.

In thecase of seawater samples, there was no relationship between BPA degradation and the change of bacterial counts. Bacterial counts at 25 and 35 ºC increased rapidly at 5 and 3 d, respectively, but decreased since then. The concentration of BPA was not changed for 30 d at both 25 and 35 ºC, but decreased from 40 to 60 d in spite of low levels of bacteria. These results show that the differentdegradation way for BPA in seawater may exist. Moreover, our study suggest that BPA in seawater than in river water can continue for longer time with no degradation and the possibility of BPA contamination on a marine organism can be higher than that on freshwater organism.

1. Introduction

Bisphenol A [BPA; 2,2-bis(4-hydroxyphenyl)propane] is made by combining acetone and phenol and is widely usedas a material for the production of epoxy resins, phenol resins, polycarbonates, polyacrylates, polyesters, and lacquer coatings on food cans (Staples et al., 1998). BPA is known as one of endocrine disruptors (Krishnan et al., 1993) and has an acute toxicity to aquatic organisms in the range of 1–10 lg/ml for freshwater and marine species (Alexander et al., 1988). The wastewaters from BPAproduction factories (Kotnrt et al., 2000) and the leachate from waste landfill (Yamamoto et al., 2001) are pointed as the sources of BPA contamination in aquatic environment.

BPA in river waters is rapidly degraded and a halflife for its degradation is average below 5 d (Dorn et al., 1987; Ike et al., 2000; Klecka et al., 2001; Kang and Kondo, 2002a). The primary factor of BPA degradation in riverwaters is bacteria (Kang and Kondo, 2002b). Recently, Kang and Kondo (2002a) reported that most bacteria (10 out of 11) isolated from three river waters had BPA biodegradability, but there were differences in removal rates of BPA (18–91%). BPA degradation in river waters is also influenced by temperature and bacterial counts (Kang and Kondo, 2002b).

However, there are fewer data on the BPAdegradation in seawater, compared with those in river water. Recently, Ying and Kookana (2003) reported that BPA was not degraded within 35 d after treatment at 20 ºC, while a rapid BPA degradation was found after 35 d, but they did not prove whether BPA degradation was due by bacteria or by others.
The purpose of this study was to identify a relationship between changes of bacterial counts and BPAdegradation in seawater under aerobic or anaerobic conditions, and at temperatures of 4, 25, and 35 ºC. The BPA extracted from water samples was detected by high-performance liquid chromatography (HPLC) with fluorescence detection.

2. Materials and methods

2.1. Samples

The seawater samples were taken from five sites of the Hyuga Bay of Miyazaki city. The sampling sites were over one kilometeraway from a junction of river and sea. A 10-1 seawater sample was collected in the sterilized glass bottles using a sampler with a glass bottle at the depth of about 1m. The samples were stored at 99%) was obtained from Nacalai Tesque, Inc. (Kyoto, Japan). Acetonitrile and methanol (HPLC grade) were purchased from Kanto Chemical Co., Inc. (Tokyo, Japan). Water used as HPLC solvent was purified...