Variation Of The Typical Estrogenic Endocrine Disrupting Chemicals In Water Treatment Processes

Estrogenic endocrine disrupting chemicals (e-EDCs) are of major concerns for humans and widelife for their adverse effects. There are few studies on e-EDCs in the conventional wastewater treatment (WWTP) and waterworks in China, such as their occurrence, removal rate in the treatment processes and their harm to aquatic widelife and humans because of their residual in the effluent. This dissertation focused on a case study of occurrence and variation of e-EDCs from the typical WWTP and wa-terworks in Beijing, China.Bioassay-directed chemical analysis (BDCA) was conducted to identify the dominant contributors to estrogenic activity of wastewater and drinking water by us-ing solid phase extraction (SPE) and silica gel-alumina column chromatography combined with a recombinant yeast bioassay for detecting estrogenic activity and gas chromato graphy-mass spectrometry (GC/MS) for quantifying estrogenic substances.By using BDCA, the dominant contributors to estrogenic activity of wastewater and drinking water were identified to make clear the occurrence of e-EDCs and varia-tion of their concentrations and estrogenic activity. In theWWTP, bisphenol A (BPA), nonylphenol (NP) and octylphenol (OP) were mainly contributors to estrogenic activ-ity in the influent. Some unknown estrogenic components were contributors to estro-genic activity in the effluent. In the waterworks, NP and phthalate esters were mainly contributed to the estrogenic activity of raw water; the increased estrogenic activity in coagulation-sedimentation process was partly from the alkylphenol in the coagulants, and the else was from the releasing of the sterols; the increased residual estrogenic activity in the finished water was probably due to the chlorination of natural organic matters (NOM) and the formation of chlorophenols.Ozone was chosen as a potential method to oxidize the e-EDCs in wastewater and drinking water. Ozone was shown to be rapid and effective to remove the estro-genic acticity of wastewater and drinking water. Although ozone could completely decomposed the estrogenic activity of 4-NP, ozonation by-products, the mixtures of 4-nonylcatechol homologues and the mixtures of 4-nonylbenzoquinone homologues have different estrogenic activity. Higher ozone concentration, lower pH, lower sus-pended solid concentration, lower ?OH inhibitor concentration, appropriate humic acid concentration and so on were favorable for the decrease of estrogenic activity of 4-NP.Estrogenic activity was recommended as a comprehensive index to evaluate the effect of e-EDCs for water quality. According to the ecological risk assessment, the safe guideline values were set for the effluent of wastewater, surface water and fin-ished water from a waterworks, respectively. The risk assessment was made for the conventional water treatment processes and improving measures were given to the concerned processes.