title: Evaluation of removal efficiency of human antibiotics in wastewater treatment plants in Bangkok, Thailand.
abstract: This study aimed to investigate the antibiotic concentration at each stage of treatment and to evaluate the removal efficiency of antibiotics in different types of secondary and advanced treatment, as well as the effects of the location of their discharge points on the occurrence of antibiotics in surface water. Eight target antibiotics and four hospital wastewater treatment plants in Bangkok with different conventional and advanced treatment options were investigated. Antibiotics were extracted by solid phase extraction and analysed by high performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS). The antibiotic with the highest concentration at influent was cefazolin at 13,166 ng/L, while the antibiotic with the highest concentration at effluent was sulfamethoxazole at 1,499 ng/L. The removal efficiency of antibiotics from lowest to highest was sulfamethoxazole, piperacillin, clarithromycin, metronidazole, dicloxacillin, ciprofloxacin, cefazolin, and cefalexin. The adopted conventional treatment systems could not completely remove all antibiotics from wastewater. However, using advanced treatments or disinfection units such as chlorination and UV could increase the antibiotic removal efficiency. Chlorination was more effective than UV, ciprofloxacin and sulfamethoxazole concentration fluctuated during the treatment process, and sulfamethoxazole was the most difficult to remove. Both these antibiotics should be studied further regarding their contamination in sludge and suitable treatment options for their removal.
authors.affiliation: Department of Civil and Environmental Engineering, Faculty of Engineering, Mahidol University, 25/25 Phutthamonthon 4 Rd, Salaya, Phutthamonthon, Nakhon Pathom 73170, Thailand E-mail: suwanna.boo@mahidol.ac.th.
authors.forename: Donwichai
authors.initials: D
authors.lastname: Sinthuchai
authors.affiliation: Department of Civil and Environmental Engineering, Faculty of Engineering, Mahidol University, 25/25 Phutthamonthon 4 Rd, Salaya, Phutthamonthon, Nakhon Pathom 73170, Thailand E-mail: suwanna.boo@mahidol.ac.th.
authors.forename: Suwanna Kitpati
authors.initials: SK
authors.lastname: Boontanon
authors.affiliation: Faculty of Environment and Resource Studies, Mahidol University, 999 Phutthamonthon 4 Rd, Salaya, Phutthamonthon, Nakhon Pathom 73170, Thailand.
authors.forename: Narin
authors.initials: N
authors.lastname: Boontanon
authors.affiliation: Department of Civil Engineering, Faculty of Engineering, Thammasat University, 99 Moo 18 Phaholyothin Rd, Khlongluang, Pathumthani 12120, Thailand.
authors.forename: Chongrak
authors.initials: C
authors.lastname: Polprasert
mesh_terms: D000900:Anti-Bacterial Agents / Q000032:analysis*; D002853:Chromatography, Liquid; D004203:Disinfection; D006761:Hospitals / Q000706:statistics & numerical data; D006801:Humans; D012722:Sewage; D052616:Solid Phase Extraction; D013420:Sulfamethoxazole / Q000032:analysis; D053719:Tandem Mass Spectrometry; D013785:Thailand; D062065:Wastewater / Q000032:analysis*; D014874:Water Pollutants, Chemical / Q000032:analysis*; D018508:Water Purification / Q000706:statistics & numerical data*
chemical_list: D000900:Anti-Bacterial Agents; D012722:Sewage; D013420:Sulfamethoxazole; D062065:Wastewater; D014874:Water Pollutants, Chemical