Occurrence And Remove Of Typical Psychiatric Pharmaceuticals In Wastewater Treatment Plants

In this study, we investigated3kinds of22typical psychiatric pharmaceuticals, including7anxiolytic-sedative-hypnotics,6antidepressants and9anti-schizophrenia drugs, and developed the method for the determination of them in municipal wastewater. On the basis, we continued to investigate the psychiatric pharmaceuticals concentrations levels in two psychiatric hospitals’(P-WWTPs) and three municipal (M-WWTPs) wastewater treatment plants in Bejing and then study their removal efficiency in five WWTPs with different treatment processes and purification mechanism. This study would contribute to improve and optimize the wastewater treatment process, provide the basic data and scientific basis to develop environmental quality standards.Based on the preliminary investigations (the literatures and the drug usage of the psychiatric hospital in Beijing region), the following commonly psychiatric drugs were studied:7sedative hypnotic drugs (including anti-anxiety-epileptic drugs),9antipsychotic drugs,6antidepressant drugs. In this study, since all analytes present basic characteristics with their amine moieties, the positive ESI ionization mode was selected, and then the parameters of mass spectrometry were defined for each drug by the injection in needle pump. Then we combined mass spectrometry with the liquid chromatography and optimizedthe liquid chromatography mobile phase and gradient elution conditions. Finally, the22drugs were completely separated within12minutes, and the linear range of analytes was wide (over2orders of magnitude) with the r over0.99.In this study, we utilized the automated solid phase extraction, and selected the suitable solid-phase extraction packing (HLB Disk) and the eluting solution (2%acetic acid methanol solution), after optimizing condition and dry time of the disk, the sample pH, the loading flow rate in the elution process, and established a fully automated solid-phase extraction method. In the method,19out of22pharmaceuticals in spiking experiments recoveries were more than80%, except olanzapine, ziprasidone, and perphenazine. Given that the municipal wastewater was complex resulting the matrix interference being serious, the SPE eluting solution should be pured using the amino column. After that the matrix effects of19pharmaceutical sranged from60%to111%, except olanzapine, ziprasidone, and perphenazine. The method quantitation limits were between0.1～8.0ng L-1in the WWTP’s influent and effluent. After the spiked experiment at the low, middle, and high concentration, the method was confirmed ultimately.In this study, the two P-WWTPs and three M-WWTPs were investigated in Beijing. Except clonazepam, other21kinds of pharmaceuticals in the wastewater were detected. In municipal wastewater, the concentrations of clozapine, sulpiride, carbamazepine and quetiapine were between10～100ng L-1, the concentrations of oxazepam, chlorpromazine, trihexyphenidyl, risperidone, clomipramine, citalopram, fluoxetine and sertraline ranged from MQL to10ng L-1, the rest pharmaceuticals of alprazolam, lorazepam, zaleplon, olanzapine, ziprasidone, aripiprazole, perphenazine, paroxetine and fluvoxamine were not detected. However, in psychiatric hospital wastewater, the concentrations of clozapine, sulpirideand quetiapine ranged between2000-10000ng L-1, the concentrations of the rest pharmaceuticals ranged from MQL to500ng L-1. This shows that the concentrations of psychiatric pharmaceuticals in the psychiatric hospital wastewater were significantly higher than that in municipal wastewater, and the psychiatric hospital wastewater is the main source of psychiatric pharmaceuticals in municipal wasterwter.The research shows that the removals of the pharmaceuticals in WWTPs vary widely. trihexyphenidyl, olanzapine, clozapine, risperidone and quetiapine were partially removed in different WWTPs processes, with more than30%removal efficiency;the removal efficiencies of the other pharmaceuticals were very low, even being negative value. The varies of the removal of the psychiatric pharmaceuticals in the different WWTPs processes show that the most pharmaceuticals were partially removed in primary treatment; the pharmaceuticals were well removed in the secondary treatment (biological treatment), and the removals of12pharmaceuticals were more than50%; but after tertiary treatment (chlorination), the removal efficiencies of14pharmaceuticals were negative, which shows that the main structure of pharmaceuticals was not been destroyed in the biological treatment process and the pharmaceuticals were discharged into the water environment after the tertiary treatment. So More attentions should be paid to control the discharge of psychiatric pharmaceuticals from pyschiatric hospital.