| In recent years, endocrine disruptors have been found in the most world’s major water bodies. Among them, estrone(E1), estradiol(E2) and ethinyl estradiol(EE2) got the most attention due to their high oestrogenic vitality. For these three substances, they would cause biological gonadal dysfunction, fertility decline and even malformation once their concentration reached the ng / L level. Therefore it is necessary to conduct a detailed discussion of how to detect and remove E1,E2 and EE2. This research is about the following fields: The removal effect of estrogen by sand filter in the process of sewage advanced treatment by using of secondary sedimentation effluent and ultrapure water; The removal effect of estrogen by sand filter with different particle size distributions(PSD) in the process of advanced treatment; The residual chlorine`s removal effect of estrogen after chlorine disinfection. The main results of the research are listed as follows:① The removal effect of estrogen by sand filter in the process of sewage advanced treatment. For E1, the removal rate caused by physical adsorption in the first 12 hours was about 14.5%, which occupied the dominant position, as the filter material reached adsorption saturation in 12~24 hour, the biodegradation changed to dominated the removal. In the 24 hour time point, the removal rate of physical adsorption amounted to 16.0%, and the amount caused by biodegradation was about 18.3%. For E2, at 0h time point, the removal effect caused by physical adsorption was relatively better, but at some moment during 0~12h, biodegradable turned into the leading role,and it occupied the dominant position in the rest of time. And during 12~24h, the concentration of E2 in 2,3 filtration column appeared increasement, which means desorption of E2 appeared in these two columns. In 24 hour time point, the E2 removal rate caused by physical adsorption and biodegradation was 3.7% and 41.2% separately. For EE2, the biological removal effect was very weak, physical adsorption occupied the dominant position in the whole test process, in 24 hour time point, the EE2 removal rate caused by physical adsorption was about 18.9%. As the residence time of sewage in filter column was inadequate, the removal rate of E1, E2 and EE2 caused by biological adsorption were all relatively low.② The removal effect of estrogen by sand with different particle size distributions(PSD) in the process of advanced treatment.Data showed that the removal efficiency of estrogen in the filter column has strong correlation with PSD water, they showed negative correlation, and could be fitted well by a logarithmic function(R2>0.9). However, as for the removal contribution, biological function showed less relevant with the change of PSD, the removal rate caused by biological function has been stable at 11.7%-14.3%, the relation between them was not significant(p>0.1); On the other hand, the removal rate of estrogen caused by adsorption was declined significantly with the increase of particle diameter(p < 0.01).③ The residual chlorine`s removal effect of estrogen after chlorine disinfection. After 3 hours of chlorine processing, E1, E2 and EE2`s removal rate reached 78.2%, 94.1% and 58.4% separately. But the removal largely concentrated on the former one hour, the rate of oxidation reduced quickly in the later time, therefore, set the contact time of chlorine and estrogen remain in 1h is most reasonable. In addition, we made the dynamic analysis for this process, we found that these three substances can meet the first-order kinetics well, the correlation coefficients of E1, E2 and EE2 were 0.9785, 0.9906 and 0.9839 separately. The order of their removal rate is: E2(0.8987/h)> E1(0.4881/h)> EE2(0.2835/h), this difference is mainly caused by the different chemical properties. However, after oxidation, the water sample still present a relatively high level of the oestrogenic vitality, the possible reason is that the new formed oxidation by-products still has certain estrogen activity. In other words, the content of E1, E2, EE2 detected decreased, but other estrogen energetic substances generated at the same time. |
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