| The Pearl Delta River is one of the most rapidly growing economics regions. Macao located on the west of the Pearl River Delta Estuary. The Macao coastal waters have served as a trap for fluvial suspended particles from the water network of the Pearl River Delta. In the same time, it also receives the municipal sewage, industrial discharge and urban runoff from the metropolitan Macao and Zhuhai Special Economic Zone of China. The previous studies have shown that the Pearl Delta River and Estuary have been polluted by many kinds of organic contamination, including of alkylphenols, ( i.e., nonylphenols (NPs), octylphenol (OP) , and polycyclic aromtic hydrocarbons (PAHs).Alkylphenols are refractory metabolites of alkylphenol polyethoxylates, a nonionic surfactant. Because alkylphenols, having unique structure, are linked to specific origin of sewage sludge, they have been proposed as anthropogenic sewage markers. PAHs are a kind of contaminants derived from multiple sources. PAHs, due to their mutagenic and carcinogenic effects on organism, together with Alkylphenols, are known to have estrogenic effects.The pollutants in the sediments have been dived into the free fraction, which can be extracted by organic solvent, and bound or nonextractable fraction, which was released by hydrolyzation from the residual sediment after solvent extraction. Vertical total concentration (sum of free and bound fractions) profiles in sediment cores can be used to reconstruct the history of pollution. According to the distribution of bound fraction, we can understand the diagenetic fate and evolvement trend of pollutants in sediments. Understanding the fate of pollutants is important when assessing their bioavailability and abilities of degradation and remobilization. In this paper, preliminary study of the history of pollution and their diagenetic fate in a sediment core from Nam Van Lake of Macao was presented.1. An analytical method to quantity the pollutants with deferent bound aspects inthe sediment was established. After the free fraction was extracted by classical Soxlet extraction, the sediment was hydrolyzed by methanol and alkali to cleave the chemical bound fractions by ester-bind linkage with sediment organic matters and to release the physical bound fraction entrapped in the hole of the organic matter in the sediment, and the bound fraction was leached with organic solvent.2. The sediments from the core in Nam Van Lake of Macao represented two different kinds of sedimentary conditions, the bottom layers (below 44cm) reflect the pollution in the estuarine sedimentary environment and upper layers (0-3 2cm) reflect the pollution in the lagoon environment. Concentration of land-derived alkylphenols (APs) in estuarine condition was higher than that in lagoon condition because that sources of APs in the estuarine condition included the urban runoffs from the upstream waters of Pearl River Delta and Macao City, but jast primarily or solely from Macao in the lagoon condition. The vertical profile of concentration of APs in the sediment core, to some degree, was correlated with the development degree of regional economy development and the proceeding of wastewater treatment. Compared to other studies from literatures, contamination of alkylphenols in the estuarine sediments is not really serious. There are not existing sediment quality guidelines for APs with which to assess the potential adverse effects of APs in the sediments on organisms in the Nam Van Lake.3. NP isomer composition in sediments throughout the core is uniform, suggesting the existence of a single major source. But selective isomer reaction (selective degradation) occurred during the wastewater treatment or during transportation and sedimentation. Binding ability between the eleven isomers of NPs is different. Binding of NP-3 with organic matter is easier than other isomers, but its binding was more affected by environmental condition.4. Binding ability of APs is stronger in the estuarine sediments than in the lagoon sediments. Binding...
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