| With the increasing pollution of water environment, more and more micro-organic pollutants are found in water, especially phthalate acid esters(PAEs), which has been detected widely in water environment and become a kind of prevalent pollutants. PAEs are cancerogenic, teratogenic and mutagenic, which are seriously harmful to human health. PAEs have been listed as the priority pollutants by many countries and widely concerned all over the world. The improvement of drinking water standards and the low removal efficiency of PAEs by conventional water treatment technology make it urgent to develop new water treatment processes and control PAEs in drinking water.Dibutyl phthalate (DBP) was chosen as a main target pollutant in this experiment which aimed at improving ozonation by the presence of metal oxides, activated carbon, hydrogen peroxide and zero valent metals. The objective of this work is to find a method which is high efficiency, simple and low cost to remove PAEs from drinking water. Results and conclusions include:Several metal oxides were prepared by different methods, andα-FeOOH,γ-Fe2O3, Mn3O4 were found to have the ability of improving DBP removal efficiency in ozonation, and the best removal efficiency was 60.7% when usingγ-Fe2O3 as the catalyst. Removal efficiency of DBP in ozonation could be enhanced greatly by adding hydrogen peroxide and more than 90% of DBP could be removed. Nanosized titanium dioxide (TiO2) had good performance to improve ozonation efficiency, and the removal efficiency of DBP could reach 80% at least by using supported nanosized TiO2. DBP removal efficiency could also be enhanced to some extent by adding activated carbon into ozonation process, but coupling use of activated carbon and hydrogen peroxide did not show synergistic effect. Zero valent iron (ZVI) and zero valent zinc (ZVZ) had excellent ability to improve ozonation efficiency, and the DBP removal efficiency was more than 90% in the experimental conditions. In acidic condition, DBP could be removed by the presence of ZVI and zero valent copper (ZVC),and ozone was not necessary to present in these two processes.DBP removal efficiency in the enhanced ozonation by using ZVI was influenced by ZVI dose, DBP concentration and pH. Under different pH conditions, the oxidation mechanisms of DBP were different. Under neutral condition,the ability of improving ozonation efficiency by the presence of ZVI was influenced by the addition of tert-butyl alcohol,which means that the reaction follow hydroxyl radical mechanism. The improvement of DBP ozonation was due to mainly the acceleration effect of ZVI itself, rather than other oxide species. DBP removal efficiency in the enhanced ozonation process using ZVI was influenced by water quality condition, and cations, anions, organic compounds in water to some extents.ZVZ had good ability to improve the ozonation efficiency of DBP, and 0.05g/L dose of ZVZ was enough to remove DBP effectively under experimental conditions. DBP removal efficiency was enhanced from the increase of ZVZ dose and pH value of the solution, and the DBP initial concentration had little influence on its removal efficiency. The efficiency of ZVZ enhanced ozonation was not inhibited by the presence of carbonate. It is also found that the inhibition of tert-butyl alcohol on this process was uncompleted, so the reaction did not follow hydroxyl radical mechanism entirely. ZVZ itself played the major role in improving ozonation process, but better efficiency was achieved after ZVZ was reused, which means that there are some species with higher activity on improving ozonation during the reaction. Under different water quality conditions, DBP removal efficiency was changed little,but some cations such as Na+, NH4+, Fe2+ and low concentration of humic acid could accelerate the removal of DBP.Under acidic condition, Zero valent copper (ZVC) had good ability to remove organic compounds from water by using dissolved oxygen. The oxidation efficiency was increased with the decrease of solution pH and the increase of ZVC dose. The initial concentration of organic compounds had a little influence on the removal efficiency. The experiment results excluded the improving effect achieved by the adsorption of ZVC, the presence of copper oxide and copper ion in the ZVC enhanced oxidation process. The TOC was decreased and mineralization was achieved in the oxidation of DEP by the presence of ZVC under acid condition. The reaction mechanism of copper enhanced oxidation process was different when using different type of acids in the experiment. When the solution pH was adjusted by sulfuric acid, dissolved oxygen was not necessary to present for ZVC enhanced oxidation process and the reaction was affected by the presence of tert-butyl alcohol, which means that the reaction follow hydroxyl radical mechanism. When pH was adjusted using hydrochloric acid, dissolved oxygen was necessary to present for the enhanced removal of organic compounds, and the reaction was not influenced by the presence of hydroxyl radical inhibitor-tert butyl alcohol. The efficiency of ZVC enhanced oxidation process was greatly influenced by the water quality condition, and the addition of iron ion could speed up the removal of DBP,but the addition of methanal inhibit the removal of DBP. After ZVC was reused, its ability of improving the oxidation process increased, and copper ion was released in the reaction process.ZVI and ZVZ enhanced ozonation can be used in the treatment of source water. The TOC and UV254 were reduced in ZVI and ZVZ enhanced ozonation process and ammonia nitrogen concentration was increased. Organic compounds with a molecular weight of 1000～10000 was removed obviously in ZVI and ZVZ enhanced ozonation process, and Organic compounds with a molecular weight about 1750 and 3800 was removed obviously in ZVC enhanced oxidation process under acidic condition. ZVI and ZVZ enhanced ozonation process could also be used in the treatment of wastewater to increase the removal efficiency of COD.
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