| The occurrence of emerging organic pollutants?EOPs?,such as pharmaceuticals and personal care products?PPCPs?,endocrine disruptors?EDCs?,antibiotics and antibiotic resistance genes?ARGs?,phthalate?PAEs?,microplastics?MPs?in the aquatic environments,is of concern due to their ubiquitous presence in the environment.The existing sewage treatment process has limited removal effect on EOPs,and it becomes main potential risk for subsequent reuse and the secondary effluent receiving water body.In this study,the occurrence,spatial characteristics,and potential environmental risks of 49 kind of EOPs were simultaneously investigated in the effluents of wastewater treatment plants?WWTPs?.The relationships between different EOPs and between the EOPs and water characteristics were investigated.The four categories of EOPs from the four reclaimed water processes effluents and receiving water of WWTP effluents were studied,including the pollution concentrations,spatial distributions of antibiotics,ARGs,PAEs and MPs.The migration and transformation of EOPs was explored.The results showed that the total concentrations of the detected EOPs were 1.65-18.95?g·L-1.Beijing-Tianjin-Hebei region(5.40-18.95?g·L-1)were is a heavily polluted area.PPCPs were the predominant species and contributed to approximately half of the total EOPs concentrations in most WWTPs.49 EOPs were detected at a ng·L-1-?g·L-11 level,and the detection frequencies of 18 compounds were over 90%.The four EOPs with the highest mean concentrations of the 49 were metoprolol(798.0ng·L-1),carbamazepine(597.5 ng·L-1),sulpiride(543.5 ng·L-1)and dimethyl phthalate(502.6 ng·L-1).The levels of some detected EOPs showed positive correlations with the nitrite nitrogen level.Roxithromycin,diclofenac acid exhibited high risks in the effluents.The main categories of EOPs in the reclaimed treatment process were ofloxacin,norfloxacin,roxithromycin,azithromycin,sulfamethoxazole of antibiotics;sul1,sul2,tetQ,ermB of ARGs;diisobutyl phthalate and di?2-ethylhexyl?phthalate of PAEs,and MPs less than 0.01 mm in the form of particles and fragments.The removal rate of antibiotics,PAEs and MPs in the membrane reclaimed treatment process was 56.7-99.5%.The removal effect of reverse osmosis?the removal rate is 90.3-98.5%?was higher than ultrafiltration and microfiltration,and air floatation pretreatment?19.5-53.1%?is higher than coagulation sedimentation?9.7-27.0%?.The removal rate of non-membrane reclaimed treatment process was lower than 74.6%,and the removal rate of flocculation precipitation to antibiotics?25.6-100%?,sand filtration to ARGs?0.22-0.44 log reduction in absolute concentration?,V-filter to PAEs?23.8-80.39%?and MPs?42.0-54.7%?were higher than other non-membrane processes.The absolute concentration of ARGs showed a gradual decline in the whole process.The removal of ARGs and intI1 by ultrafiltration and reverse osmosis was significant?concentration reduction 0.51-2.14 log?,and the absolute concentration of total ARGs in the reclaimed water was reduced to 103-104 copies·L-1.The main categories of EOPs in the receiving water body were the same as these in WWTP effluents.The concentration of antibiotics and PAEs in the lake area decreased by 46.3-86.1%within a short distance of 0.1 km from the outfall,while the concentration of river-type receiving water decreased by 25.6-84.4%within a distance of 1.0 km.The absolute concentrations of ARGs in winter and spring were105-108 copies·L-1.The concentration of MPs in the upstream water body was 103-1630 L-1,and the concentration in the downstream monitoring section of the outfall was 510-4458 L-1.There was no obvious seasonal or regional variation in concentration of MPs. |
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