Advancedtreatment Of Endocrine Disruptors In Drinking Water

With the development of industry and agriculture, water pollution is increasing significantly and drinking water pollution is also more and more seriously. Endocrine disruptors is a toxic substance of the organic pollutant. It is a kind of exogenous chemicals, and it can interfere with the normal hormone organism produces, release, transfer, metabolism, reaction, and eliminate, and interferes and damages the endocrine system seriously. Conventional wastewater treatment procrsses are not effective methods to eliminating all endocrine disruptors from wasterwater. In thie thesis, we mainly investigated progesterone and medroxyprogesterone removal by ozonation-AC adsorption in drinking water. The investigation focused on the technology optimization, kinetics model, degradation mechanism, the acute toxicity and AC adsorption of progesterone. Research results are as follows.(1) Kinetics on degradation efficiency of medroxyprogesterone by ozonation was investigated in this paper. Results showed that medroxyprogesterone could be degraded effectively by ozonation, with a first-order kinetics in continuous ozone aeration system and a second-order kinetics in semibatch ozone aeration system. The increases of pH and the addition of HCO3- would bring negative effects to the degradation. The degradation efficiencies of medroxyprogesterone decreased from 89.8% to 54.8% with pH increase from 3.10 to 9.02, and the rate constant k decreased from 0.1463 L·(mg·min)-1 to 0.0495 L·(mg·min)-1 and the degradation efficiencies decreased 22.2 percentage points with the addition of HCO3-, in semibatch aeration system.(2) Ozonation can effectively degrade progesterone, and ozone degradation obeyed first-order kinetics and degradation rate of progesterone could reach 90%. The degradation rate of progesterone in acidic system is faster, as the degradation efficiencies of progesterone decreased from 97% to 55% with pH increased from 3.10 to 11.03. HCO3-,Cl- and SO42- existed in natural water were negative to the degradation process of progesterone except NO3-. NO3- showed a positive effect to the degradation of progesterone. Mass spectrometry analyses were performed to investigate primary degradation pathway generated by the reaction of ozone with progesterone. Results showed that there were two by-products formed. The were A and B with the masses of 334 g·mol-1 and 346 g·mol-1 separately.(3) The coal activated carbon and coconut shell activated carbon were used to adsorption progesterone, the removal rate of progesterone is more than 85%. And the adsorption process of two kinds activated carbon accorded with Freundlich isothermal adsorption equation, R2>0.98. Through use the zebra fish as test biological, we get the result as the LC50 of progesterone is 0.73 mg·L-1, EC0 is 0.5 mg·L-1, EC100 is 1.0 mg·L-1. All parameters could reach the standards by ozone-AC process in source water, especially,activated carbon absorption is able to remove formaldehyde and BrO3- produced by oxidation, the removal rate of formaldehyde was 85% and BrO3- was 100%.