Oxidation kinetics of selected pharmaceutical compounds and their degradation during ozonation of secondary treated municipal wastewater effluent (MWWE) was investigated. The apparent second-order rate constants for the reaction between chlorotetracycline (CTC), enrofloxacin (ENR), gemfibrozil (GEM) and ozone ranged between 6.82 – 52.7 × 104 M−1s−1. The measured second-order hydroxyl radical rate constants were several orders of magnitude higher at 8.4 × 109 – 13.1 × 109 M−1s−1 with a reactivity sequence of GEM > CTC > ENR. Overall degradation of CTC, ENR and GEM in secondary treated municipal wastewater effluent was >76 % at ozone doses of 0.33 mg O3/mg DOC or higher.

The present study is an overview of the literature on the occurrence and potential risks of pharmaceutical substances in the wastewater treatment plants (WWTP), natural waters and drinking water treatment plants served by the Great Lakes Basin (Canada and the USA) between the years of 2007-2012. Large number of pharmaceutical substances, including anti-inflammatories, lipid regulators, antidepressants, antibiotics, beta blockers, anti-epileptics, anti-hypertensions and stimulants, in high ng/L concentrations, has been reported in the WWTP influents. Most of these compounds have also been detected in the WWTP effluents at comparable concentrations with the exception of caffeine, cotinine and salicylic acid suggesting the inefficiency of conventional treatment processes in the degradation of pharmaceutical compounds. Decreasing surface water concentrations have been observed with the distance downstream of the discharge point due to the dilution effect. Surface waters located around septic systems and agricultural areas have also been found to be contaminated with pharmaceutical substances. Carbamazepine, caffeine, its metabolite paraxanthine, ibuprofen, gemfibrozil and sulfamethoxazole have been frequently detected in the surface waters. The number of occurrences of carbamazepine, ibuprofen, naproxen, gemfibrozil, bezafibrate, sulfamethoxazole and macrolide antibiotics in drinking water sources, at ng/L concentration ranges, has been quite high. Although the detection frequencies in treated drinking waters were relatively low, the concentrations of the above mentioned pharmaceutical substances were at the same range as the source water concentrations. Six of the detected pharmaceutical substances, namely, fluoxetine, sulfamethoxazole, clarithromycin, erythromycin, carbamazepine and esterone exhibit a high environmental risk in Great Lakes WWTP effluents and surface waters, while none of the pharmaceutical substances seem to pose a risk for human health at their highest reported concentrations in the drinking water sources from the Great Lakes.

The reactivity of selected compounds in Lake Huron water was evaluated during ozone/hydrogen peroxide-based advanced oxidation process (AOP) and conventional treatment (coagulation–sedimentation–filtration). Elimination of these compounds via advanced oxidation and conventional treatment processes were strongly related to their molecular structures. Overall removal of target compounds was quite similar in effluents from both the AOP and the combined treatment process (AOP + conventional) with the exception of fluoxetine. Reaction rate constants for the decomposition of the target compounds were substantially higher during AOP compared to conventional treatment alone.

The destruction of antibiotic-resistant microorganisms at the source of contamination is necessary due to their adverse effects and to their increasingly widespread occurrence in the environment. To address this problem, Fenton and ozone oxidation processes were applied to synthetically contaminated cow manure to remove the tetM gene and its host, Escherichia coli HB101. The efficiency of the processes was evaluated by enumeration of E. coli HB101 and by PCR amplification of the tetM gene. The results of this study show that 56.60% bacterial inactivation (corresponding to a 0.36 log reduction) was achieved by a Fenton reagent dose of 50 mM H(2)O(2) and 5 mM Fe(2+) without acidifying the manure. Despite the high organic content of cow manure, 98.50% bacterial inactivation (corresponding to a 1.83 log reduction) was obtained by the ozonation process with an applied dose of 3.125 mg ozone/g manure slurry. The PCR study revealed that the band intensity of the tetM gene gradually decreased by increasing the Fenton reagent and the applied ozone dose. However, significantly high doses of oxidants would be required to completely eliminate bacterial pollution in manure.

An integrated treatment method based on magnesium salt extraction followed by chemical oxidation was used for the treatment of a veterinary antibiotic, oxytetracycline (OTC) contaminated cow manure since animal manure can be an important source for antibiotic pollution in the environment. Pretreatment with magnesium salt enhanced the efficiencies of subsequent oxidation processes by extracting 63.9% of OTC from the manure thereby making it more favorable for oxidation with the hydroxyl radicals produced by the Fenton and ozone oxidation processes. Both the 24 h Fenton oxidation process with 434 mM H(2)O(2) and 43.4 mM Fe(2+) doses and the 1-h ozonation process with an applied ozone dose of 2.5 mg min(-1) provided more than 90% OTC removal from the manure slurry. However, the second-order OTC removal rate constant of Fenton process (119 M(-1)s(-1)) was remarkably lower than that obtained with the ozonation process (548 M(-1)s(-1)). The oxidant dose was a significant factor for the efficiency of the Fenton treatment but not for the ozone treatment. The efficiencies of both the Fenton and ozone oxidation processes were not affected by the pH adjustment of the manure slurry.

Simultaneous degradation of oxytetracycline (OTC) and sulfamethazine (SMZ) antibacterials in synthetically contaminated cow manure (20 mg of antibacterials/kg of manure) in the presence and absence of bedding was investigated by the application of ozone, Fenton, and persulfate oxidation processes. Almost the complete removal of antibacterials was attained with all oxidation processes, which were combined with a pretreatment of manure with magnesium (Mg(2+)) salt desorption. Among the investigated oxidation processes, thermally activated persulfate oxidation with 25 mM Na(2)S(2)O(8) at 50 degrees C was also applied to the animal feeding operations wastewater, and the pseudo-first-order degradation rate constants of OTC and SMZ were found as 3.22 and 1.25 (1/h), respectively. Thermally activated persulfate treatment resulted in the reduction of 82% inhibition of OTC and SMZ to 7%, indicating the production of almost nontoxic degradation products in the wastewater.

The efficiency of ozonation on the degradation of oxytetracycline, a veterinary antibiotic, has been investigated in both cow manure and synthetic animal feeding operation wastewater at varying experimental conditions. With a rapid degradation of antibiotic in synthetic wastewater, ozonation improved its biodegradability and eliminated bacterial toxicity caused by oxytetracycline. The degradation rate of oxytetracycline depended on pH and applied ozone dose, but not initial antibiotic concentration in wastewater. In the case of manure treatment, ozonation efficiency in terms of oxytetracycline degradation was negatively affected by moisture and antibiotic content of manure. The degradation rate of oxytetracycline in manure slowed down upon the extension of treatment time since ozone could not react with strongly adsorbed antibiotic on manure. Increase in humic and fulvic acid carbon and mineral nitrogen content was an indicator for the improvement of fertilizing value of manure by ozonation.

A simple analytical method for the quantitative analysis of fluoroquinolone group antibiotics, enrofloxacin (ENR) and ciprofloxacin (CIP) in soil was developed based on the mechanical extraction with vortex and ultrasonication and solid phase extraction followed by high pressure liquid chromatography-fluorescence detection (HPLC-FLD). Type of extraction solvents and number of extraction cycles were optimized during the method development. The most efficient extraction solvent was found as phosphate buffer at pH 3 in combination with 50% of organic modifier acetonitrile with the extraction cycle of four. Overall method was applied on three different types of soils, namely, sandy, loamy sand and sandy loam and recovery rates ranged between 71–100% for ENR and 61–89% for CIP depending on the portion of organic and clay content in soils. The analytical method was also used for the estimation of fluoroquinolone concentrations in manure amended agricultural soils sampled from the different parts of Turkey and enrofloxacin was detected in the concentration range of 0.013–0.204 mg/kg. In addition, sorption of fluoroquinolone antibiotics on all types of soils was investigated and the highest distribution coefficients (Kd and Kf) of fluoroquinolone compounds were obtained for loamy sand (Kd = 1.29 l/g and Kf = 0.66 for CIP; Kd = 0.97 l/g and Kf = 0.56 for ENR) with the highest organic carbon.

In order to produce biodegradable products, four different synthetically prepared wastewaters containing cephalosporine (ceftriaxone sodium), penicillin (penicillin VK and amoxicillin) and quinolone (enrofloxacin) group antibiotics at typical concentrations encountered in pharmaceutical formulation effluent were pretreated by ozonation. BOD5/COD and SOUR (specific oxygen uptake rate) were the parameters for the assessment of biodegradability of ozonation products. The results of HPLC analysis indicated that the complete removal of each antibiotically active substance was achieved within the short time period of ozonation. Depending upon the type of antibiotic in the synthetic wastewater. 65-81 % COD and 20-98% aromaticity (UV254) removals were obtained, with a 2960 mg/L.h ozone dosage applied at pH 7 (CODi = 900 mg/L). Ozonation brought about a rise in the BOD5/COD ratio of enrofloxacin-containing wastewater from an initial value of 0.02 to a maximum of 0.33. and this ratio was increased from 0 to 0.07, 0.28 and 0.42, for ceftriaxone sodium, penicillin VK and amoxicillin-containing wastewaters, respectively.

The treatment of synthetically prepared antibiotic formulation wastewater with O3, O3/H2O2, and O3/UV processes was examined. The efficiencies of the treatment processes were compared by means of COD, absorbance removals, and biodegradability enhancement. The efficiencies of O3/pH = 7, O3/ pH = 12, and O3/H2O2(50 mM) processes were almost identical in terms of COD and UV254 removals. The BOD5/COD ratio of formulation wastewater increased from 0.02 to 0.38 and 0.5 at the end of 1 hr of ozone treatment at pH = 7 and pH = 12, respectively. For the formulation wastewater subjected to O3/UV process at pH = 7, parallel to the UV254 removal efficiency, a 20% increase was obtained in the Oxygen Uptake Rate (OUR) value compared to that of mere ozonation.

Ozonation of three different synthetic pharmaceutical formulation wastewater containing two human antibiotics and a veterinary antibiotic has been studied to enhance the their biodegradability. The effects of pH and initial chemical oxygen demand (COD) value as well as addition of hydrogen peroxide on ozonation process were investigated. Total organic carbon (TOC), COD, biochemical oxygen demand (BOD), and aromatic content (UV254) were the parameters followed to evaluate the performance of ozonation process. Comparison of the biodegradability of selected wastewaters containing different antibiotics confirmed that the variation of biodegradability was associated with the target compound. While BOD5/COD ratio of veterinary antibiotic formulation wastewater was increased from 0.077 to 0.38 with an applied ozone dosage of 2.96 g/l, this ratio for human antibiotic I and human antibiotic II was increased from 0 to 0.1 and 0.27 respectively. Moreover the results of this investigation showed that the ozonation process is capable of achieving high levels of COD and aromaticity removals at about their natural pH values.

This study examines the application of photochemical and non-photochemical advanced oxidation processes on the treatment of textile, Kraft bleaching, photoprocessing, and pharmaceutical wastewaters. Effects of reaction conditions on the treatment efficiency of industrial wastewater have been investigated. The results were evaluated in terms of biodegradability enhancement. The results indicated depending upon the composition of wastewater and applied pretreatment all applied AOPs had an ability to increase the biodegradability of studied wastewaters.