Occurrence and environmental risk assessment of 24 pharmaceuticals and personal care products in wastewater treatment plants in Jiangsu

-This study determined the occurrence, removal and environmental risk assessment of 24 multi-class pharmaceuticals and personal care products (PPCPs) in wastewater treatment plants (WWTPs) of Jiangsu Province, China. Solid phase extraction was used for pre-concentration of the samples with ultra-performance liquid chromatography coupled with tandem mass spectrometry analysis following. Results indicated that the maximum concentrations of the PPCPs varied between 2.15 ng/L and 6234 ng/L in influents and effluents. Quinolone antibiotics, macrolide antibiotics, cephalosporin antibiotics, lotions and other drugs were detected more commonly. Above the calculation of the risk quotient, clarithromycin and sulfamethoxazole showed high potential environmental risk for acute toxicity.


Introduction
Pharmaceuticals and personal care products (PPCPs) are a class of compounds that are widely used and excreted in everyday life.They contain a variety of medicinal compounds, such as antibiotics, anti-inflammatory analgesics, central stimulants, antiepileptic drugs, contraceptives and so on, and compounds related to daily care activities, such as personal care products and cosmetics, solvents, aromatics, sunscreens, styling agents and others.They have brought huge benefits and solved many problems.
After use, PPCPs always discharge to the drains, cause their ingredients in sewage levels were elevated (Radhakrishnan Yedhu Krishnan et al., 2021).Sewage is the major source of these pollutants (Li et al., 2016;Gomez et al., 2007).The occurrence of PPCPs in the environment as emerging contaminants has been a subject of concern for the scientific community and the public since 2000.Scientists have reported that some PPCPs have been connected with ecological impacts at trace concentrations (Kolpin et al., 2002).If PPCPs are not removed by WWTPs, they can impact wildlife in receiving waters.The risk quotient (RQ) is to evaluate potential ecotoxicological risks (Rudd et al., 2014;Gros et al., 2010).
The study determined the occurrence of 24 PPCPs in influent and effluent wastewaters from 18 WWTPs situated in Jiangsu.Evaluated each compound in all WWTPs for removal rates and frequency, to provide an overview of their biodegradability and evaluate the effectiveness of treatments currently applied in Jiangsu WWTPs.The potential environmental risks were evaluated for PPCPs, finally we provide a comprehensive data set of PPCPs in WWTP influents and effluents in Jiangsu Province, which were compared with recent literature from other areas in China and around the world.

Site description and sample collection
The 18 selected WWTPs are located in Jiangsu Province, and they service populations in the range of 3,000-17,000.Collected these sample in amber glass bottles, then stored at 4°C until extraction (within 48 hr).when these samples arrival, using 0.45 µm glass fiber filters (Advantec MFS, USA) to preserved by filtering at once and adjusting the pH to 2-3 (used concentrated hydrochloric acid).

Sample pretreatment
Using 0.45 µm glass fiber filters filtered water samples.After filtration, 1 L of supernatant was passed through an Oasis HLB cartridge (500 mg, 6 mL), preconditioned with 5.0 mL MeOH and 5.0 mL water.The measured volumes were afterwards preconcentrated onto a cartridge.Baker vacuum system was set of 5 mL/min.Evaporating the extracts to dryness, reconstituting with 1 mL of MeOH and vortex-mixed for 2-3 min.Using 0.22 µm organic membranes filtered the extracts.Finally, transferred extracts into auto-sampler vials for the determination of PPCPs by HPLC coupled with tandem mass spectrometry (MS/MS) techniques.

Quality control
Detailed information about the recovery, repeatability, reproducibility and LOQ of the PPCPs from spiked blank water samples are briefly listed in Table 1.Recoveries of spiked PPCPs into samples ranged between 60% and 127% for influent, between 61% and 121% for effluent.The relative standard deviation was below 20%.The LOQ ranged from 0.31 to 5.87 ng/L for influent and 0.87 to 16.16 ng/L for effluent.

Occurrence of PPCPs in WWTPs
Of the 24 target compounds, two chloramphenicol antibiotics, three sulfanilamide antibiotics, three quinolone antibiotics, four macrolide antibiotics, six analgesics and anti-inflammatories, one cephalosporin antibiotic, two lipid regulators and cholesterol lowering statin drugs, one lotion and two other drugs were quantified.In the effluent, the amounts of PPCPs found in the effluent depended on the RE of the WWTP.In this study, sulfanilamide antibiotics, quinolone antibiotics, macrolide antibiotics and cephalosporin antibiotics all showed higher concentrations than influent samples.Cephalexin showed the highest concentration, followed by sulfamethoxazole, ofloxacin, norfloxacin, roxithromycin, with average concentrations in the effluent of 527.12, 395.70, 232.12, 145.72 and 113.63 ng/L, respectively.Concentrations of cephalexin, sulfamethoxazole, norfloxacin and ofloxacin were higher than concentrations in the Czech Republic (Golovko et al.,2014) and Xia'men, China (Qian et al., 2016).The concentration of roxithromycin was comparable with results obtained in Canada (Guerra et al., 2013).Lower but still considerable levels of naproxen, sulfapyridine, clarithromycin, ibuprofen, salicylic acid, trimethoprim, erythromycin, lomefloxacin, azithromycin, indometacin, carbamazepine, gemfibrozil and florfenicol were found, ranged between 4.93 ng/L and 102.43 ng/L.The lowest concentrations were found for chloramphenicol, bezafibrate, atenolol, ketoprofen and triclocarban with average concentrations of 3.46, 2.25, 1.86, 1.35 and 0.88 ng/L, respectively.The average level of these five PPCPs was much lower than in Portugal (Pereira et al., 2016), Volos, Greece (Papageorgiou et al., 2016), Spain and Canada (Guerra et al., 2013).
Many PPCPs were detected 100% in influent and effluent samples (including 2 lipid regulators and cholesterol lowering statin drugs, 4 macrolide antibiotics, 3 quinolone antibiotics, 3 analgesics and antiinflammatories, 1 cephalosporin antibiotic, 1 lotion and 1 chloramphenicol antibiotic).Sulfapyridine, trimethoprim and carbamazepine were detected less than half of the samples.

Overall removal of PPCPs
The REs of the target PPCPs in the WWTPs varied (Fig. 2).High REs were observed for salicylic acid, sulfapyridine and ketoprofen, with mean values of >80%, followed by chloramphenicol and ibuprofen, with mean REs of 73.71% and 78.93%, respectively, similar to previously available data (Qian et al., 2016).The RE of antibiotics ranged between −70.27% (sulfamethoxazole) and 80.17% (for sulfapyridine).The RE of drugs ranged from 3.08% (carbamazepine) to 90.38% (salicylic acid).The RE value of triclocarban was −45.28%.Triclocarban, erythromycin, sulfamethoxazole, ofloxacin and florfenicol always had negative RE values, which were comparable to previous studies (Gracia-Lor et al., 2012; Qian et al., 2016).Many compounds presented a variety of REs, include negative REs. Sampling mode, sample preservation, method biases and atmospheric deposition all could lead to negative removal rates (Kuster et al., 2008).Generally, the WWTPs of Jiangsu were not able to efficiently remove most of the PPCPs.The results of this study and others clearly demonstrate that a range of removal rates can be defined.

Risk assessment
The RQ values in the effluents of the WWTPs of Jiangsu were conducted, for fish, crustaceans and algae for acute and chronic toxicity were shown in Figs 3 and 4 The results showed that two of the analyzed compounds (clarithromycin and sulfamethoxazole) posed high acute risk (RQ > 1) in algae but none of the compounds posed high chronic risk.For acute toxicity in crustaceans and algae, sulfapyridine, ofloxacin, norfloxacin and erythromycin displayed medium risk (0.1 < RQ < 1; Fig. 3).For chronic toxicity in fish and algae, sulfamethoxazole, roxithromycin, norfloxacin and salicylic acid displayed medium risk (Fig. 4).Two

Conclusions
The occurrence, removal and environmental risk assessment of 24 PPCPs in 18 municipal WWTPs that employed the A 2 /O process in Jiangsu, China, were studied.The maximum concentrations of the PPCPs varied between 2.15 ng/L and 5076 ng/L in the influents and between 3.83 ng/L and 6234 ng/L in the effluents; mean values ranged from 0.41 ng/L up to 768.05 ng/L and from 0.88 ng/L to 527.12 ng/L in influent and effluent, respectively.High detection rate of PPCPs were the quinolone antibiotics, macrolide antibiotics, cephalosporin antibiotics, lotions, and other drugs.The REs demonstrating that the WWTPs were not able to efficiently remove the complex mixture of PPCPs.From the calculation of the RQ on three trophic levels, clarithromycin and sulfamethoxazole posed high potential environmental risk for acute toxicity.These investigations have shown that substances of pharmaceutical origin are often not eliminated during wastewater treatment.The extent of contamination by PPCPs is increasing, particularly as the Chinese population grows and ages, and reliance on pharmaceutical treatments continues to increase, which might have important implications for environmental monitoring and risk assessment.

Fig. 1
Fig. 1 Location of the cities involved in the study.The sampling site Map, including all wastewater treatment plants(WWTPs)

Fig. 2
Fig. 2 Average removal of target PPCPs in the WWTPs.

Fig. 3
Fig.3 Risk quotients for PPCPs in effluent wastewaters were estimated for fish (a), crustaceans (b) and algae (c) for acute toxicity.
PPCPs posed high acute ecotoxicological risk and six PPCPs posed medium risk for algae.Obtained were consistent with other studies (Kosma et al., 2014; Papageorgiou et al., 2016; Backhaus and Karlsson, 2015).Clarithromycin and sulfamethoxazole showed high environmental risk in acute toxicity, they might be considered priority compounds of concern in WWTP effluents.

Fig. 4
Fig.4 Risk quotients for PPCPs in effluent wastewaters were estimated for fish (a), crustaceans (b) and algae (c) for chronic toxicity.

Table 2
(Golovko et al.,2014) 2016)ncentration, frequency of detection and removal efficiency (RE) of target pharmaceuticals measured in wastewater. ) had the five highest concentrations.The highest level of mean values was observed for cephalosporin antibiotics (with the single contribution of cephalexin).Cephalexin, a broad spectrum antibiotic, is commonly used to treat influenza, indigestion and various kinds of inflammation.It is not metabolized in the body, so the influent concentration of cephalexin in WWTPs was high.Influent levels of PPCPs are largely comparable to previous literatures; the average levels of cephalexin and salicylic acid in influent wastewater were lower than those obtained in Australia and Volos, Greece(Papageorgiou et al., 2016).The concentrations of sulfamethoxazole, sulfapyridine and ofloxacin in this study were comparable to the results of other studies in the Czech Republic(Golovko et al.,2014), and Xia'men, The average level of atenolol was the lowest in the influent samples.Influent levels of atenolol, triclocarban, bezafibrate, gemfibrozil and florfenicol concentrations were all lower than those found in Volos, Greece(Papageorgiou et al., 2016), Spain and Canada (Guerra et al., 2013), Portugal (Pereira et al., 2015) and southern China (Chen et al.,2015).