Research On The Removal Efficiency Of PPCPs In Vertical Flow Constructed Wetlands With Different Plants

Pharmaceutical and personal care products(abbreviated as PPCPs)are frequently detected in water environments.Although the concentration is very low,they may cause long-term adverse effects on the aquatic environment,the ecological toxicity effects are difficult to predict,which may cause potential threats to animal and human health.Constructed wetlands have strong removal efficiency for organic pollutants,especially for PPCPs,it is economical and effective to choose the constructed wetlands treat PPCPs sewage.The research chooses commonly antiphlogistic drugs ibuprofen and the antibiotic roxithromycin as the research objects in PPCPs.The design and construction of vertical flow constructed wetland simulator,which filled with gravel packing,and selected the Canna indica,Arundo donax var,Umbellifera planted in wetlands and set no plants controls for comparison.A method of solid-phase extraction with high performance liquid chromatography(HPLC)was established,the chromatographic column and mobile phase conditions were screened to obtain the best detection effect.In the study,water samples were taken from a pharmaceutical factory and a hospital in chongqing.Measured the contents of roxithromycin was 567?g/L in the pharmaceutical factory sewage,and the concentration of roxithromycin was 2.27?g/L(the factory mainly produced ibuprofen during the period).The concentrations of ibuprofen and roxithromycin were separately 12.03?g/L and 2.73?g/L in the hospital wastewater.Setting the pharmaceuticals concentration of inflow refers to the pharmaceuticals concentration of actual water environment.Finally,selecting the intermediate concentration,and the concentration determined to be 100?g/L.The simulated sewage is fed into is the device,the effects of different plants constructed wetlands on the degrade research objects were studied,and research the removal efficiency influence of season,hydraulic retention time and influent pattern to ibuprofen and roxithromycin.Finally,single factor analysis of variance and two-way analysis of variance were carried out for the relevant experimental datas.The results showed that the sort order of roxithromycin removal efficiency was Arundo donax var,Canna indica,Umbellifera and no plants controls,the Arundo donax var control has the best removal efficiency to roxithromycin,up to 94.06%.The sorting for removal effect of ibuprofen was: Canna indica,Arundo donax var,Umbellifera and no plants controls,the Canna indica control has the highest removal efficiency to ibuprofen,which reached 69.74%.Three plants controls constructed wetlands have better removal efficiency to ibuprofen and roxithromycin than the controls without plants,which proved that the presence of plants was beneficial to the removal of roxithromycin and ibuprofen.Through the analysis of the variance,the plant types had a significant effect on the removal of roxithromycin,and no significant effect on the removal of ibuprofen.The average removal efficiency of roxithromycin in the four groups of constructed wetlands was 77.85%~81.06% in winter,and the average removal efficiency of ibuprofen was 39.14%~61.09%,the two datas are lower than the removal efficiency in summer,the results showed that constructed wetlands has better removal effeciency of roxithromycin and ibuprofen in summer.The removal efficiency of the two pharmaceuticals in a rapid quick feeding(5000 ml/min)better than in slow feeding(13 ml/min).By comparing the removal effects of the two pharmaceuticals hydraulic retention time at 1d,2d and 4d,to found that the most of roxithromycin have been removed at HRT=2d,so the 2d is the relatively appropriate hydraulic retention time.Increasing hydraulic retention time can make ibuprofen more fully degraded by biological in constructed wetlands,and its best hydraulic retention time is 4 days in the experiment.Through analysis of variance,it can be seen that season,hydraulic retention time and influent pattern have significant effects on removing of ibuprofen and roxithromycin in three controls constructed wetlands with plants(except that the season has no significant effects on canna indica control),Whether removing ibuprofen or roxithromycin,plant types have obvious interaction with season,and the experimental group of roxithromycin plant types have obvious interaction with influent pattern.Due to the the restriction of time and experiment conditions,no specific percentage about plants and microorganismscan removing ibuprofen and roxithromycin was given in this paper.In the future,it is waiting for continue to explore,the mechanism of constructed wetlands removing PPCP will more specific and clear.