Pollution of HCHs, DDTs and PCBs in tidal flat of Hangzhou Bay 2009–2013

Abstract

The concentration and distribution of three persistent organic pollutants (hexachlorocyclohexanes (HCHs), dichlorodiphenyltrichloroethanes (DDTs) and polychlorinated biphenyls (PCBs)) was assessed in tidal fl at sediments collected from the south bank of Hangzhou Bay, China from 2009 to 2013. Gas chromatography coupled to triple quadrupole mass spectrometry (GC-MS/MS) was used for analysis, based on United States Environmental Protection Agency methods EPA8080A, EPA8081B, and EPA3550B. The results showed that the levels of HCHs, DDTs and PCBs decreased in the order of DDTs > HCHs > PCBs, and their mass fractions ranged from 0.29-32.91, 0.09-13.19 and 0.16-4.10 μg/kg (dry mass), respectively. The levels of HCHs, DDTs and PCBs decreased slowly from 2009 to 2013, with considerably greater concentrations in winter than in spring and summer. In this study area, the concentrations of DDTs and HCHs decreased gradually towards the mouth of Hangzhou Bay, while the concentrations of PCBs were related to changes in the local economy. In addition, the sources of HCHs and DDTs were identifi ed as atmospheric precipitation and historical residues. Finally, we predicted that PCBs pollution primarily originated from Aroclor 1254(Lot A4), which might root in the illegal demolition and stacking of abandoned paint, transformer or electronic equipment in the south bank of Hangzhou Bay.

Advances in pretreatment and analysis methods of aromatic hydrocarbons in soil

“…The traditional Soxhlet extraction is time-consuming, solvent consuming, non-environmentally friendly and non-economical. Compared with Soxhlet extraction, ultrasonic treatment 146 is more rapid and practical in extracting hydrocarbons from soil. In recent years, research attention has been attracted to solvent-free extraction techniques, such as static headspace, 108 purge and trap, solid-phase microextraction 118 for extraction of BTEX and PAHs from soil.…”