© by PSP Volume 26 – No. 3/2017, pages 2422-2429 Fresenius Environmental Bulletin 2422 REMOVAL OF OXYTETRACYCLINE ANTIBIOTICS FROM HOSPITAL WASTEWATER Abdolkazem Neisi 1 , Majid Farhadi 2 , Afshin Takdastan 3 , Ali Akbar Babaei 4 , Ahmad Reza Yari 5 , Mohammad Javad Mohammadi 6,7, *, Mehdi Vosoughi 7 1 Environmental Technologies Research Center and Department of Environmental Health Engineering, School of Public Health, Ahvaz Jundishapur University of Medical Sciences, Ahvaz, Iran 2 Environmental health Engineering, school of health, Ahvaz Jundishapur University of Medical Sciences, Ahvaz, Iran 3 Environmental Technologies Research Center, Ahvaz Jundishapur University of Medical Sciences, Ahvaz, Iran 4 Environmental Technologies Research Center, Ahvaz Jundishapur University of Medical Sciences, Ahvaz, Iran 5 Research Center for Environmental Pollutants, Qom University of Medical Sciences, Qom, Iran 6 Abadan School of Medical Sciences, Abadan, Iran 7 Student Research Committee, Department of Environmental Health Engineering, School of Public Health and Environmental Technologies Research Center, Ahvaz Jundishapur University of Medical Sciences, Ahvaz, Iran ABSTRACT Harmful effects of antibiotics on the human body are disturbing intestinal balance and gastrointestinal disorders. The aims of this study were to detect the Oxytetracycline (OTC) in the effluent of Wastewater Treatment Plants (WTPs) of Golestan, Abuzar and Taleghani hospitals of Ahvaz, Iran; also, the evaluation of the efficiency of treatment plants for removal of OTC. This study was a cross sectional study. Samples were collected from influent and effluent of the hospitals WTPs in summer, autumn and winter. 42 samples were collected in composite form in all week days. Samples were extracted for Oxytetracycline by passing through SPE column. Ethanol and extracted OTC have been dried with nitrogen gas. Then, OTC inoculated 2 ml methanol and analyzed by HPLC. Highest Oxytetracycline concentration was observed in Taleghani hospital WTP in the summer (0.372 mg/L). The maximum removal of percentage was in the summer (97%). Lowest Oxytetracycline concentration was observed in the winter in Abuzar and Golestan hospitals WTPs. Minimum removal percentage of OTC was in autumn for Golestan hospital WTP (10%). Extended Aeration Activated Sludge (EAAS) is capable to remove oxytetracycline, with an average percentage of 53%. Oxytetracycline removal was increased in the hot season and decreased in cold season. KEYWORDS: Extended Aeration, Activated Sludge, Hospital wastewater, Oxytetracycline. INTRODUCTION In recent years, more pollutants are threaten for the source of drinking water, agriculture and industrial uses in Ahvaz, Iran [1-6]. Antibiotics are organic chemical matters produced by organisms. They kill other organisms, humans, animals and plants [7]. Uptake and excretion of antibiotics are different and depend on antibiotic type [8]. Antibiotics are persistent and lipophilic; they can maintain their chemical structure in body long time for therapeutic purposes [9, 10]. Excessive use of antibiotics may cause bacterial resistance [11]. Since antibiotics have health benefits for humans and animals, indiscriminate use of antibiotics leads to their accumulation in the environment, especially in sewage and hospital wastewater [12-16]. Annually, many antibiotics are consumed worldwide. Europe consumption is about 19.5 packs per 1,000 people [17, 18]. Harmful effects of antibiotics on body include disruptions in intestinal balance and unpredictable consequences on human health and the environment; in fact, it can disrupt the digestive system. Hospital wastewater may contain high levels of pathogenic microorganisms, pharmaceutical residues, metabolites of pharmaceuticals, radioactive elements and other hazardous chemicals [19-21]. Several studies indicate Oxytetracycline presence in hospital wastewater [22-24]. Antibiotics include limited range and wide-ranging antibiotics; Oxytetracycline is broad-spectrum [25, 26]. Oxytetracycline is one of the tetracyclines which is continuously observed in the aquatic environment [27, 25, 28, 29]. Oxytetracycline can be found in surface water, wastewater, groundwater, drinking water, seawater and sediment in all over the world [30, 25, 31, 32, 1, 33]. Presence of oxytetracycline can choose microorganisms variation in natural environments, development of resistance in bacteria or pathogens [30, 25, 34, 35]. Also, Oxytetracycline as growth promoters is used in fish and aquaculture [10, 25]. After a poor absorption, about 70% of Oxytetracycline is excreted from the body through urine and feces [30, 10, 8, 25]. Removal of antibiotics from wastewater include physical