Reviews - Multi-Process - Riverbank Filt - Coagulation - Oxidation - Biofiltration - Adsorption - Membranes
Single PPCP - Other
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| Snyder, S.A., Wert, E.C., Lei, H., Westerhoff, P. and Yoon, Y. (2007) Removal of EDCs and Pharmaceuticals in Drinking and Reuse Treatment Processes, AWWA Research Foundation, #91188 |
Target compounds spiked into water and treated with bench-scale processes and pilot-scale. Full-scale monitoring was conducted to determine treatment effectiveness. Processes studied included coagulation, softening, GAC, PAC, NF, UF, chlorination, chloramination, ozonation, mixed oxidants, UV, biodegradation and soil adsorption. |
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| Hoppe-Jones, C., Oldham, G. and Drewes, J.E. (2010) Attenuation of total organic carbon and unregulated trace organic chemicals in US riverbank filtration systems. Water Research 44(15), 4643-4659. |
There is increasing concern regarding the presence of unregulated trace organic chemicals in drinking water supplies that receive discharge from municipal wastewater treatment plants. In comparison to conventional and advanced drinking water treatment, riverbank filtration represents a low-cost and low-energy alternative that can attenuate total organic carbon (TOC) as well as trace organic chemicals (TOrC). This study examined the role of predominant redox conditions, retention time, biodegradable organic carbon, and temperature to achieve attenuation of TOC and TOrC through monitoring efforts at three full-scale RBF facilities in different geographic areas of the United States. The RBF systems investigated in this study were able to act as a reliable barrier for TOC, nitrogen, and certain TOrC. Temperature (seasonal) variation played an important role for the make-up of the river water quality and performance of the RBF systems. Temperatures of less than 10 C did not affect TOC removal but resulted in diminished attenuation of nitrate and select TOrC |
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| Suarez, S., Lerna, J.M. and Omil, F. (2009) Pre-treatment of hospital wastewater by coagulation-flocculation and flotation. Bioresource Technology 100(7), 2138-2146. |
Coagulation-flocculation and flotation processes were evaluated for the pre-treatment of hospital wastewater, including the removal of 13 pharmaceutical and personal care products (PPCPs). Coagulation-flocculation assays were performed in a jar-Test device and in a continuous pilot-scale plant. Raw hospital wastewater as well as the effluent from the continuous coagulation plant were treated in a flotation cell. Removal of total suspended solids (TSS) during pre-treatment was very effective, reaching an average removal efficiency of 92% in the combined coagulation-flotation process. Musk fragrances were eliminated to a high degree during batch coagulation-flocculation (tonalide: 83.4 +/- 14.3%; galaxolide: 79.2 +/- 9.9%; celestolide: 77.7 +/- 16.8%), presumably due to their strong lipophilic character which promotes the interaction of these compounds with the lipid fraction of solids. For cliclofenac (DCF), naproxen (NPX) and ibuprofen (IBP) maximum removals of 46%, 42% and 23%, respectively, were obtained, while the rest of PPCPs were not affected by the physico-chemical treatment. Flotation of raw wastewater led to slightly worse results compared to coagulation-flocculation, although the combined action of both improved the overall efficiency of the process. The proposed pre-treatment strategy for hospital wastewater is useful for assimilating its conventional physico-chemical characteristics to that of municipal wastewater as well as for reducing the load of some PPCPs into the sewer system. |
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| Ben Abdelmelek, S., Greaves, J., Ishida, K.P., Cooper, W.J. and Song, W. (2011) Removal of Pharmaceutical and Personal Care Products from Reverse Osmosis Retentate Using Advanced Oxidation Processes. Environmental Science & Technology 45(8), 3665-3671. | The application of reverse osmosis (RO) in water intended for reuse is promising for assuring high water quality. However, one significant disadvantage is the need to dispose of the RO retentate (or reject water). Studies focusing on Pharmaceutical and Personal Care Products (PPCPs) have raised questions concerning their concentrations in the RO retentate. Advanced oxidation processes (AOPs) are alternatives for destroying these compounds in retentate that contains high concentration of effluent organic matter (EfOM) and other inorganic constituents. Twenty-seven PPCPs were screened in a RO retentate using solid phase extraction (SPE) and UPLC-MS/MS, and detailed degradation studies for 14 of the compounds were obtained. Based on the absolute hydroxyl radical (HO center dot) reaction rate constants for individual pharmaceutical compounds, and that of the RO retentate (EfOM and inorganic constituents), it was possible to model their destruction. Using excitation-emission matrix (EEM) fluorescence spectroscopy, the HO center dot oxidation of the EfOM could be observed through decreases in the retentate fluorescence, The decrease in the peak normally associated with proteins correlated well with the removal of the pharmaceutical compounds. These results suggest that fluorescence may be a suitable parameter for monitoring the degradation of PPCPs by AOPs in RO retentates. | |
| Rosario-Ortiz, F.L., Wert, E.C. and Snyder, S.A. (2010) Evaluation of UV/H2O2 treatment for the oxidation of pharmaceuticals in wastewater. Water Research 44(5), 1440-1448. |
Advanced oxidation treatment using low pressure UV light coupled with hydrogen peroxide (UV/H2O2) was evaluated for the oxidation of six pharmaceuticals in three wastewater effluents. The removal of these six pharmaceuticals (meprobamate, carbamazepine, dilantin, atenolol, primidone and trimethoprim) varied between no observed removal and >90%. The role of the water quality (i.e., alkalinity, nitrite, and specifically effluent organic matter (EfOM)) on hydroxyl radical ((OH)-O-center dot) exposure was evaluated and used to explain the differences in pharmaceutical removal between the three wastewaters. Results indicated that the efficacy of UV/H2O2 treatment for the removal of pharmaceuticals from wastewater was a function of not only the concentration of EfOM but also its inherent reactivity towards (OH)-O-center dot. The removal of pharmaceuticals also correlated with reductions in ultraviolet absorbance at 254 nm (UV254), which offers utilities a surrogate to assess pharmaceutical removal efficiency during UV/H2O2 treatment. | |
| Chu, W., Wang, Y.R. and Leung, H.F. (2011) Synergy of sulfate and hydroxyl radicals in UV/S(2)O(8)(2)-/H(2)O(2) oxidation of iodinated X-ray contrast medium iopromide. Chemical Engineering Journal 178, 154-160. | The degradation of iodinated X-ray contrast medium, iopromide, by UV irradiation with the assistance of combined oxidants of S(2)O(8)(2-) and H(2)O(2) has been investigated. The effects of various parameters, including different wavelengths of UV irradiation, UV intensities, initial solution pH levels, dosages of oxidants, dosing sequence, and the presence of non-target organic matters, have been evaluated. The iopromide decay follows pseudo-first-order kinetics. The UV at 254 nm exhibits higher decay rate of iopromide than the others (300 and 350 nm) due to stronger photon energy of 254 nm and the relatively higher absorptivity of S(2)O(8)(2-), H(2)O(2) and iopromide nearby this wavelength. Optimum pH level was determined to be around 4.34. The mechanism is complicated because of the involvement of the scavenging, recombination, self-decomposition and/or stability of the involved oxidant (S(2)O(8)(2-) and H(2)O(2)) and radicals (SO(4)(center dot-) and HO(center dot)) as discussed in the paper. lopromide decay rate is linearly proportional to the [S(2)O(8)(2-)], however a nonlinear-optimal rate was observed by varying [H(2)O(2)] due to the formation of weaker radicals via overdosing of H(2)O(2). Additionally, the sequential addition of S(2)O(8)(2-) to UV/H(2)O(2) or H(2)O(2) to UV/S(2)O(8)(2) was found no better than the UV/S(2)O(8)(2-)/H(2)O(2). This is because the quenching of already formed SO(4)(center dot-) by newly added H(2)O(2) (or vice versa the quenching of HO(center dot) by S(2)O(8)(2-)). The simultaneous addition of S(2)O(8)(2-) and H(2)O(2), however, will slightly delay the generation rates of SO(4)(center dot-) and OH(center dot) due to the competition of photons between S(2)O(8)(2-) and H(2)O(2), which can reduce both the radical-scavenging reactions and the peak radical concentration in the solution, thus maximizing the utilization of precious radicals. The presence of non-target organics, especially the humic acid, in the UV/S(2)O(8)(2-)/H(2)O(2) process will quench the radicals, a pre-treatment is recommended to lessen this problem in real application. | |
| Quintana, J.B., Rodil, R., Lopez-Mahia, P., Muniategui-Lorenzo, S. and Prada-Rodriguez, D. (2010) Investigating the chlorination of acidic pharmaceuticals and by-product formation aided by an experimental design methodology. Water Research 44(1), 243-255. | The degradation of seven acidic drugs and two metabolites during chlorination was investigated by liquid chromatography-mass spectrometry (LC-MS). A triple-quadrupole (QqQ) system was used to follow the time course of the pharmaceuticals and by-products, while a quadrupole time-of-flight (Q-TOF) system was also used for the identification of the by-products. Under strong chlorination conditions (10 mg/L Cl-2, 24 h), only four of the target compounds were significantly degraded: salicylic acid, naproxen, diclofenac and indomethacine. The degradation kinetics of these four compounds were investigated at different concentrations of chlorine, bromide and pH by means of a Box-Behnken experimental design. Depending on these factors, measured pseudo-first order half-lives were in the ranges: 23-573 h for salicylic acid, 13-446 min for naproxen, 5-328 min for diclofenac and 0.4-13.4 min for indomethacine. Also, it was observed that chlorine concentration was the overall most significant factor, followed by the bromide concentration (except for indomethacine), resulting in increased degradation kinetics as they are increased. The degradation path of salicylic acid, naproxen and diclofenac consisted of aromatic substitution of one or two hydrogens by chlorine and/or bromide. Moreover, for diclofenac, two other by-products corresponding to a decarboxylation/hydroxylation pathway from the monohalogenated products were also identified. On the other hand, indomethacine degradation did not lead to halogenation products but to oxidation ones. The investigation of these by-products in real samples by LC-MS/MS (QqQ) showed that the halogenated derivates of salicylic acid occurred in all the drinking water and wastewater samples analysed. | |
| Acero, J.L., Benitez, F.J., Real, F.J. and Roldan, G. (2010) Kinetics of aqueous chlorination of some pharmaceuticals and their elimination from water matrices. Water Research 44(14), 4158-4170. | Apparent rate constants for the reactions of four selected pharmaceutical compounds (metoprolol, naproxen, amoxicillin, and phenacetin) with chlorine in ultra-pure (UP) water were determined as a function of the pH. It was found that amoxicillin (in the whole pH range 3-12), and naproxen (in the low pH range 2-4) presented high reaction rates, while naproxen (in the pH range 5-9), and phenacetin and metoprolol (in the pH range 2.5-12 for phenacetin, and 3-10 for metoprolol) followed intermediate and slow reaction rates. A mechanism is proposed for the chlorination reaction, which allowed the evaluation of the intrinsic rate constants for the elementary reactions of the ionized and un-ionized species of each selected pharmaceutical with chlorine. An excellent agreement is obtained between experimental and calculated rate constants by this mechanism. The elimination of these substances in several waters (a groundwater, a surface water from a public reservoir, and two effluents from municipal wastewater treatment plants) was also investigated at neutral pH. The efficiency of the chlorination process with respect to the pharmaceuticals elimination and the formation THMs was also established. It is generally observed that the increasing presence of organic and inorganic matter in the water matrices demand more oxidant agent (chlorine), and therefore, less chlorine is available for the oxidation of these compounds. Finally, half-life times and oxidant exposures (CT) required for the removal of 99% of the four pharmaceuticals are also evaluated. These parameters are useful for the establishment of safety chlorine doses in oxidation or disinfection stages of pharmaceuticals in treatment plants | |
| Pocostales, J.P., Sein, M.M., Knolle, W., von Sonntag, C. and Schmidt, T.C. (2010) Degradation of Ozone-Refractory Organic Phosphates in Wastewater by Ozone and Ozone/Hydrogen Peroxide (Peroxone): The Role of Ozone Consumption by Dissolved Organic Matter. Environmental Science & Technology 44(21), 8248-8253. | Ozonation is very effective in eliminating micropollutants that react fast with ozone (k > 10(3) M-1 s(-1)), but there are also ozone-refractory (k < 10 M-1 s(-1)) micropollutants such as X-ray contrast media, organic phosphates, and others. Yet, they are degraded upon ozonation to some extent, and this is due to (OH)-O-center dot radicals generated in the reaction of ozone with organic matter in wastewater (DOM, determined as DOC). The elimination of tri-n-butyl phosphate (TnBP) and tris-2-chloroisopropyl phosphate (TCPP), added to wastewater in trace amounts, was studied as a function of the ozone dose and found to follow first-order kinetics. TnBP and TCPP concentrations are halved at ozone to DOC ratios of similar to 0.25 and similar to 1.0, respectively. The (OH)-O-center dot rate constant of TCPP was estimated at (7 +/- 2) x 10(8) M-1 s(-1) by pulse radiolysis. Addition of 1 mg H2O2/L for increasing the (OH)-O-center dot yield had very little effect. This is due to the low rate of reaction of H2O2 with ozone at wastewater conditions (pH 8) that competes unfavorably with the reaction of ozone with wastewater DOC. Simulations based on the reported (Nothe et al., ES&T 2009, 43, 5990-5995) (OH)-O-center dot yield (13%) and (OH)-O-center dot scavenger capacity of wastewater (3.2 x 10(4) (mgC/ L)(-1) s(-1)) confirm the experimental data. Based on a typically applied molar ratio of ozone and H2O2 of 2, the contribution of H2O2 addition on the (OH)-O-center dot yield is shown to become important only at high ozone doses. | |
| Lee, Y. and von Gunten, U. (2010) Oxidative transformation of micropollutants during municipal wastewater treatment: Comparison of kinetic aspects of selective (chlorine, chlorine dioxide, ferrate(VI), and ozone) and non-selective oxidants (hydroxyl radical). Water Research 44(2), 555-566. | Chemical oxidation processes have been widely applied to water treatment and may serve as a tool to minimize the release of micropollutants (e g pharmaceuticals and endocrine disruptors) from municipal wastewater effluents into the aquatic environment The potential of several oxidants for the transformation of selected micropollutants such as atenolol, carbamazepine, 17 alpha-ethinylestradiol (EE2), ibuprofen, and sulfamethoxazole was assessed and compared The oxidants include chlorine, chlorine dioxide, ferrate(VI), and ozone as selective oxidants versus hydroxyl radicals as non-selective oxidant. Second-order rate constants (k) for the reaction of each oxidant show that the selective oxidants react only with some electron-rich organic moieties (ERMs), such as phenols, anilines, olefins, and deprotonated-amines in contrast, hydroxyl radicals show a nearly diffusion-controlled reactivity with almost all organic moieties (k > 10(9) M-1 s(-1)) Due to a competition for oxidants between a target micropollutant and wastewater matrix (i e effluent organic matter, EfOM), a higher reaction rate with a target micropollutant does not necessarily translate into more efficient transformation For example, transformation efficiencies of EE2, a phenolic micropollutant, in a selected wastewater effluent at pH 8 varied only within a factor of 7 among the selective oxidants, even though the corresponding k for the reaction of each selective oxidant with EE2 varied over four orders of magnitude in addition, for the selective oxidants, the competition disappears rapidly after the ERMs present in EfOM are consumed In contrast, for hydroxyl radicals, the competition remains practically the same during the entire oxidation Therefore, for a given oxidant dose, the selective oxidants were more efficient than hydroxyl radicals for transforming ERMs-containing micropollutants, while hydroxyl radicals are capable of transforming micropollutants even without ERMs Besides EfOM, ammonia, nitrite, and bromide were found to affect the micropollutant transformation efficiency during chlorine or ozone treatment. | |
| Jose, H.J., Gebhardt, W., Moreira, R., Pinnekamp, J. and Schroder, H.F. (2010) Advanced Oxidation Processes for the Elimination of Drugs Resisting Biological Membrane Treatment. Ozone-Science & Engineering 32(5), 305-312. | The recalcitrant pharmaceutical compounds carbamazepine, clofibric acid, diazepam, and diclofenac were monitored in municipal wastewater by ESI-LC-MS and -MS-MS in positive and negative mode. Although biological treatment by conventional and membrane bioreactor failed, the advanced oxidation methods using ozone (O3), O3/UV or hydrogen peroxide in combination with UV (H2O2/UV), successfully achieved their complete elimination. Target compounds could be confirmed as permanently present pollutants in Aachen-Soers wastewater in concentrations between 0.006 and 1.9 g L-1 prior to AOP treatment resulting in a complete elimination. | |
| Ijpelaar, G.F., Harmsen, D.J.H., Beerendonk, E.F., van Leerdam, R.C., Metz, D.H., Knol, A.H., Fulmer, A. and Krijnen, S. (2010) Comparison of Low Pressure and Medium Pressure UV Lamps for UV/H2O2 Treatment of Natural Waters Containing Micro Pollutants. Ozone-Science & Engineering 32(5), 329-337. |
UV/H2O2 advanced oxidation is an effective barrier against organic micro pollutants. Several studies have focused on the degradation of a wide range of pollutants, but regarding the comparison of low-pressure mercury lamps (LP) with medium-pressure mercury lamps (MP) with respect to energy consumption by the UV/H2O2 process, little is known so far. Although the absorbance of H2O2 at 254 nm is low, the results of this research show that the yield of hydroxyl radical formation (OHCT) with LP lamps is comparable or higher than with MP lamps. In a water matrix with a background absorbance due to organics and nitrate, H2O2 absorbs UV light very effectively at 254 nm. Generally, due to the contribution of direct photolysis, the degradation of pollutants is better with MP-UV/H2O2 than with LP-UV/H2O2 at the same UV fluence. Therefore, with LP-UV/H2O2 micro pollutants are predominantly degraded through reaction with OH radicals. However, due to the much higher efficiency of LP lamps in converting electrical energy to UV-C light, the energy required to achieve 90% degradation (EEO) of pesticides and pharmaceuticals can be significantly lower with LP-UV/H2O2 than with MP-UV/H2O2. Results of bench-scale tests show EEO data of the LP-UV/H2O2 process to be 30%-50% lower than for the MP-UV/H2O2 process. At these process conditions MS2 phage inactivation was found to be more than 8 logs for both MP-UV/H2O2 and LP-UV/H2O2. | |
| Garoma, T., Umamaheshwar, S.K. and Mumper, A. (2010) Removal of sulfadiazine, sulfamethizole, sulfamethoxazole, and sulfathiazole from aqueous solution by ozonation. Chemosphere 79(8), 814-820. |
The removal of sulfadiazine, sulfamethizole, sulfamethoxazole, and sulfathiazole from aqueous solution by ozonation was studied. The study was conducted experimentally in a semi-batch reactor under different experimental conditions, i.e., varying influent ozone gas concentration, bicarbonate ion concentration, and pH. The results of the study indicated that ozonation could be used to effectively remove the sulfonamides from water. The sulfonamides exhibited moderate reactivity towards aqueous ozone, k(O3) > 2 x 10(4) M-1 s(-1) at pH of 2 and 22 degrees C. The mol of ozone absorbed by the solution per mol of sulfonamides removed varied in the range of 5.5-12.0 with lower ranges representing ozone absorption by the solution at the beginning of the ozonation process whereas higher ratios correspond to >99.9% removal of the target sulfonamides. The removal rate of the sulfonamides improved with bicarbonate ion concentration up to 8 mM but further increase in bicarbonate ion decreased removal efficiency. It was also observed that increasing the pH from 2.0 to 10.0 resulted in enhanced removal of the sulfonamides. | |
| Coelho, A.D., Sans, C., Esplugas, S. and Dezotti, M. (2010) Ozonation of NSAID: A Biodegradability and Toxicity Study. Ozone-Science & Engineering 32(2), 91-98. | This work deals with the biodegradability and toxicity of three non-steroidal anti-inflammatory drugs (NSAID) (diclofenac, ibuprofen and naproxen) treated by ozonation. The results show that the total removal of 200 mg L-1 of diclofenac and 100 mg L-1 of naproxen is possible using an ozone dose of 0.20 and 0.04 g L-1, respectively. For 200 mg L-1 of ibuprofen, 90% removal is achieved using an ozone dose of 2.3 g L-1. The BOD5/COD ratio, the Zahn-Wallens test and EC50 toxicity test (Microtox) are chosen as biological and toxicity indicators of NSAID intermediates. The evolution of BOD5/COD ratio during 1 hour of treatment is evaluated and the results show that ozonation improves the biodegradability for the three NSAID treated solution. The Zahn-Wellens test for diclofenac and ibuprofen solutions shows that biological mineralization, after 28 days, is higher for diclofenac than for ibuprofen solution. According to the Microtox test, the treatment with ozone removes the toxicity of the naproxen solution. Taking into account the results obtained with the biocompatibility tests it could be assumed that ozonation is an adequate treatment for removal NSAID in aquatic medium, and the ozonated effluents could be post-treated in a biological wastewater facility. | |
| Jeong, J., Jung, J., Cooper, W.J. and Song, W. (2010) Degradation mechanisms and kinetic studies for the treatment of X-ray contrast media compounds by advanced oxidation/reduction processes. Water Research 44(15), 4391-4398. | The presence of iodinated X-ray contrast media compounds (ICM) in surface and ground waters has been reported. This is likely due to their biological inertness and incomplete removal in wastewater treatment processes. The present study reports partial degradation mechanisms based on elucidating the structures of major reaction by-products using gamma-irradiation and LC-MS. Studies conducted at concentrations higher than observed in natural waters is necessary to elucidate the reaction by-product structures and to develop destruction mechanisms. To support these mechanistic studies, the bimolecular rate constants for the reaction of (center dot)OH and e(aq)(-) with one ionic ICM (diatrizoate), four non-ionic ICM (iohexol, iopromide, iopamidol, and iomeprol), and the several analogues of diatrizoate were determined. The absolute bimolecular reaction rate constants for diatrizoate, iohexol, iopromide, iopamidol, and iomeprol with (center dot)OH were (9.58 +/- 0.23)x10(8), (3.20 +/- 0.13)x10(9), (3.34 +/- 0.14)x10(9), (3.42 +/- 0.28)x10(9), and (2.03 +/- 0.13)x10(9) M(-1) s(-1), and with e(aq)(-) were (2.13 +/- 0.03)x10(10), (3.35 +/- 0.03)x10(10), (3.25 +/- 0.05)x10(10), (3.37 +/- 0.05)x10(10), and (3.47 +/- 0.02) x 10(10) M(-1) s(-1), respectively. Transient spectra for the intermediates formed by the reaction of (center dot)OH were also measured over the time period of 1-100 mu s to better understand the stability of the radicals and for evaluation of reaction rate constants. Degradation efficiencies for the (center dot)OH and e(aq)(-) reactions with the five ICM were determined using steady-state gamma-radiolysis. Collectively, these data will form the basis of kinetic models for application of advanced oxidation/reduction processes for treating water containing these compounds. | |
| Watts, M.J. and Linden, K.G. (2009) Advanced Oxidation Kinetics of Aqueous Trialkyl Phosphate Flame Retardants and Plasticizers. Environmental Science & Technology 43(8), 2937-2942. | Trialkyl phosphate esters are a class of anthropogenic organics commonly found in surface waters of Europe and North America, due to their frequent application as flame retardants, plasticizers, and solvents. Four trialkyl phosphate esters were evaluated to determine second-order rates of reaction with ultraviolet- and ozone-generated center dot OH in water. Tris(2-butoxyethyl) phosphate (TBEP) was fastest to react with center dot OH (k(OH,TBEP) = 1.03 x 10(10) M-1 s(-1)), followed sequentially by tributyl phosphate (TBP), tris(2-chloroethyl) phosphate RCER and tris(2-chloroisopropyl) phosphate (TCPP) (kOH,TBP = 6.40 x 10(9), k(OH,TCEP) = 5.60 x 10(8), and k(OH,TCPP) = 1.98 x 10(8) M-1 s-1). A two-stage process was used to test the validity of the determined kOH for TBEP and the fastest reacting halogenated alkyl phosphate, TCEP. First, center dot OH oxidation of TCEP and TBEP, in competition with nitrobenzene was measured in ozonated hydrogen peroxide solutions. Applying multiple regression analysis, it was determined that the UV/H2O2 and O-3/H2O2 data sets were statistically identical for each compound. The subsequent validated kOH were used to predict TCEP and TBEP photodegradation in neutral pH, model surface water after chemical oxidant addition and UV irradiation (up to 1000 mJ/cm(2)). The insignificant difference between the predicted TBEP and TCEP photordegradation and a best-fit of the first-order exponential decay function to the observed TBEP and TCEP concentrations with increasing UV fluence was further evidence of the validity of the determined k(OH). TBEP oxidation rates were similar in the surface waters tested. Substantial TCEP oxidation in the model surface water required a significant increase in initial H2O2. | |
| Radjenovic, J., Godehardt, M., Petrovic, M., Hein, A., Farre, M., Jekel, M. and Barcelo, D. (2009) Evidencing Generation of Persistent Ozonation Products of Antibiotics Roxithromycin and Trimethoprim. Environmental Science & Technology 43(17), 6808-6815. | The mechanism of product formation during ozonation of two widely used antimicrobial agents, macrolide roxithromycin and inhibitor of dihydrofolate reductase (DHFR) trimethoprim was studied in laboratory-scale experiments with two types of matrix: distilled water and secondary wastewater effluent The structures of the primary and secondary reaction intermediates were elucidated by quadrupole-time-of-flight (QqToF) instrument, showing that in spite of their high ozone affinity both roxithromycin and trimethoprim oxidation pathway involve to a great degree the center dot OH radical chain reactions. In total nine ozonation products were detected, whereas two products of roxithromycin exhibited high refractoriness to ozonation, especially in the case of distilled water. Furthermore, the intact tertiary amine moiety of roxithromycin in these products suggests that the antimicrobial activity of the parent compound will be preserved. | |
| Dodd, M.C., Kohler, H.P.E. and Von Gunten, U. (2009) Oxidation of Antibacterial Compounds by Ozone and Hydroxyl Radical: Elimination of Biological Activity during Aqueous Ozonation Processes. Environmental Science & Technology 43(7), 2498-2504. | A wide variety of antibacterial compounds is rapidly oxidized by O-3 and hydroxyl radical ((OH)-O-center dot) during aqueous ozonation. Quantitative microbiological assays have been developed here or adapted from existing methods and utilized to measure the resulting changes in antibacterial potencies during O-3 and (OH)-O-center dot treatment of 13 antibacterial molecules (roxithromycin, azithromycin, tylosin, ciprofloxacin, enrofloxacin, penicillin G, cephalexin, sulfamethoxazole,trimethoprim, lincomycin, tetracycline, vancomycin, and amikacin) from 9 structural classes (macrolides, fluoroquinolones, beta-lactams, sulfonamides, dihydrofolate reductase inhibitors, lincosamides, tetracyclines, glycopeptides, and aminoglycosides), as well as the biocide triclosan. Potency measurements were determined from dose-response relationships obtained by exposing Escherichia coli or Bacillus subtilis reference strains to treated samples of each antibacterial compound via broth micro- or macrodilution assays and related to the measured residual concentrations of parent antibacterial in each sample. Data obtained from these experiments show that O-3 and (OH)-O-center dot reactions lead in nearly all cases to stoichiometric elimination of antibacterial activity (i.e., loss of 1 mole equivalent of potency per mole of parent compound consumed). The beta-lactams penicillin G (PG) and cephalexin (CP) represent the only clear exceptions, as bioassay measurements indicate that biologically active products may be formed in the reactions of these two compounds with both O-3 and (OH)-O-center dot. The active product(s) generated in the direct reaction of O-3 with PG appear(s) to be recalcitrant to further transformation by O-3, though any biologically active products formed in the reactions of CP with O-3, or of either PG or CP with (OH)-O-center dot, are apparently deactivated by further reactions with O-3 or (OH)-O-center dot, respectively. Thus, with few exceptions, it can be expected that municipal wastewater ozonation will generally yield sufficient structural modification of antibacterial molecules to eliminate their antibacterial activities, whether oxidation results from selective reactions with O-3 or from relatively nonselective reactions with incidentally produced (OH)-O-center dot. | |
| Broseus, R., Vincent, S., Aboulfadl, K., Daneshvar, A., Sauve, S., Barbeau, B. and Prevost, M. (2009) Ozone oxidation of pharmaceuticals, endocrine disruptors and pesticides during drinking water treatment. Water Research 43(18), 4707-4717. | This study investigates the oxidation of pharmaceuticals, endocrine disrupting compounds and pesticides during ozonation applied in drinking water treatment. In the first step, second-order rate constants for the reactions of selected compounds with molecular ozone (k(O3)) were determined in bench-scale experiments at pH 8.10: caffeine (650 +/- 22 M-1 s(-1)), progesterone (601 +/- 9 M(-1)s(-1)), medroxyprogesterone (558 +/- 9 M(-1)s(-1)), norethindrone (2215 +/- 76 M-1 s(-1)) and levonorgestrel (1427 +/- 62 M-1 s(-1)). Compared to phenolic estrogens (estrone, 17 beta-estradiol, estriol and 17 alpha-ethinylestradiol), the selected progestogen endocrine disruptors reacted far slower with ozone. In the second part of the study, bench-scale experiments were conducted with surface waters spiked with 16 target compounds to assess their oxidative removal using ozone and determine if bench-scale results would accurately predict full-scale removal data. overall, the data provided evidence that ozone is effective for removing trace organic contaminants from water with ozone doses typically applied in drinking water treatment. Ozonation. removed over 80% of caffeine, pharmaceuticals and endocrine disruptors within the CT value of about 2 mg min L-1. As expected, pesticides were found to be the most recalcitrant compounds to oxidize. Caffeine can be used as an indicator compound to gauge the efficacy of ozone treatment. | |
| Benitez, F.J., Acero, J.L., Real, F.J. and Roldan, G. (2009) Ozonation of pharmaceutical compounds: Rate constants and elimination in various water matrices. Chemosphere 77(1), 53-59. | The ozonation of four pharmaceuticals (metoprolol, naproxen, amoxicillin, and phenacetin) in ultra-pure (UP) water was studied in the pH range between 2.5 and 9. The experiments allowed the determination of the apparent rate constants for the reactions between ozone and the selected compounds. The values obtained varied depending on the pH, and ranged between 239 and 1.27 x 10(4) M-1 s(-1) for metoprolol; 2.62 x 10(4) and 2.97 x 10(5) M-1 s(-1) for naproxen; 2.31 x 10(3) and 1.21 x 10(7) M-1 s(-1) for amoxicillin: and 215 and 1.57 x 10(3) M-1 s(-1) for phenacetin. Due to the acidic nature of these substances, the degree of dissociation of each pharmaceutical was determined at every pH of work, and the specific rate constants of the neutral and ionic species formed were evaluated. Additionally, the simultaneous ozonation of the pharmaceuticals in different water matrices was carried out by considering a groundwater, a surface water from a public reservoir, and three secondary effluents from municipal wastewater treatment plants. The influence of the operating conditions (initial ozone dose, nature of pharmaceuticals and type of water) on the pharmaceuticals elimination efficiency was established, and a kinetic model was proposed for the evaluation of the partial contribution to the global oxidation of both, the direct ozonation reaction and the radical pathway. |
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| Dickenson, E.R.V. and Drewes, J.E. (2010) Quantitative structure property relationships for the adsorption of pharmaceuticals onto activated carbon. Water Science and Technology 62(10), 2270-2276. | Isotherms were determined for the adsorption of five pharmaceutical residues, primidone, carbamazepine, ibuprofen, naproxen and diclofenac, to Calgon Filtrasorb 300 powdered activated carbon (PAC). The sorption behavior was examined in ultra-pure and wastewater effluent organic matter (EfOM) matrices, where more sorption was observed in the ultra-pure water for PAC doses greater than 10 mg/L suggesting the presence of EfOM hinders the sorption of the pharmaceuticals to the PAC. Adsorption behaviors were described by the Freundlich isotherm model. Quantitative structure property relationships (QSPRs) in the form of polyparameter linear solvation energy relationships were developed for simulating the Freundlich adsorption capacity in both ultra-pure and EfOM matrices. The significant 3D-based descriptors for the QSPRs were the molar volume, polarizability and hydrogen-bond donor parameters. | |
| Redding, A.M., Cannon, F.S., Snyder, S.A. and Vanderford, B.J. (2009) A QSAR-like analysis of the adsorption of endocrine disrupting compounds, pharmaceuticals, and personal care products on modified activated carbons. Water Research 43(15), 3849-3861. |
Rapid small-scale column tests (RSSCTs) examined the removal of 29 endocrine disrupting compounds (EDCs) and pharmaceutical/personal care products (PPCPs). The RSSCTs employed three lignite variants: HYDRODARCO 4000 (HD4000), steam-modified HD4000, and methane/steam-modified HD4000. RSSCTs used native Lake Mead, NV water spiked with 100-200 ppt each of 29 EDCs/PPCPs. For the steam and methane/steam variants, breakthrough occurred at 14,000-92,000 bed volumes (BV); and this was 3-4 times more bed volumes than for HD4000. Most EDC/PPCP bed life data were describable by a normalized quantitative structure-activity relationship (i.e. QSAR-like model) of the form: BVp = ((TPV x rho(mc))(e(0.2812xpHs))/CV x C-o)(0.2758 x (8)chi(p) + 0.0011 x FOSA) where TPV is the pore volume, rho(mc) is the apparent density, CV is the molecular volume, C-o is the concentration, (8)chi(p) depicts the molecule's compactness, and FOSA is the molecule's hydrophobic surface area. |
| Citation | Notes | Abstract |
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| Simon, A., Nghiem, L.D., Le-Clech, P., Khan, S.J. and Drewes, J.E. (2009) Effects of membrane degradation on the removal of pharmaceutically active compounds (PhACs) by NF/RO filtration processes. Journal of Membrane Science 340(1-2), 16-25. |
The impacts of membrane degradation due to chlorine attack on the rejection of pharmaceutically active compounds (PhACs) by nanofiltration and reverse osmosis membranes were investigated in this study. Membrane degradation was simulated by soaking the membranes in a sodium hypochlorite solution of various concentrations over 18 h. Changes in membrane surface properties were characterised by contact angle measurement, atomic force microscopy analysis, and streaming potential measurement. The impacts of hypochlorite exposure to the membrane separation processes were ascertained by comparing the rejection of PhACs by virgin and chlorine-ex posed membranes. Overall, the reverse osmosis BW30 membrane and the tight nanofiltration NF90 membrane were much more resilient to chlorine exposure than the larger pore size TFC-SR2 and NF270 nanofiltration membranes. In fact, rejection of all three PhACs selected in this study by the BW30 remained largely unchanged after hypochlorite exposure and further characterisation did not reveal any evidence of compromised separation capability. In contrast, the effects of chlorine exposure to the two loose nanofiltration membranes were quite profound. While chlorine exposure generally resulted in reduced rejection of PhACs, a small increase in rejection was observed when a more dilute hypochlorite solution was used. Changes in the membrane surface morphology as well as observed rejection of inorganic salts and PhACs were found to be consistent with mechanisms of chlorine oxidation of polyamide membranes reported in the literature. Chlorine oxidation consistently resulted in a more negative zeta potential of all four membranes investigated in this study. Conformational alterations of the membrane polyamide active skin layer were also evident as reflected by changes in surface roughness before and after chlorine exposure. Such alterations can either loosen or tighten the effective membrane pore size, leading to either a decrease or an increase in rejection. Both of these phenomena were observed in this study, although the decrease in the rejection of PhACs was overwhelming from exposure to highly concentrated hypochlorite solution |
| Citation | Notes | Abstract |
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| Rodayan, A., Roy, R. and Yargeau, V. (2010) Oxidation products of sulfamethoxazole in ozonated secondary effluent. Journal of Hazardous Materials 177(1-3), 237-243. |
Sulfamethoxazole | In this study the antibiotic sulfamethoxazole (SMX) was subjected to ozone treatment. Solutions of 60 mg/L and 100 mu g/L SMX in pure water and secondary municipal effluent were treated. The removal profile of SMX and its oxidation products was monitored as a function of transferred ozone dose in both matrices. No difference was observed in the ozone dose required for the concentration of SMX to fall below the limit of detection in pure water and wastewater. New peaks with the same retention times were obtained on the HPLC chromatograms for all conditions studied. Solutions with an initial concentration of 60 mg/L required 83 mg/L of ozone to fall below the limit of detection and eight oxidation products were detected. Solutions with an initial concentration of 100 mu g/L required 14 mg/L of ozone and only four oxidation products were detected. The four peaks obtained during experiments at low concentration were observed at the same retention times as four of the peaks obtained in higher concentration samples. In ozonated wastewater these products were identified as: 4-aminobenzene sulfonamide, N-(3-phenylpropyl)-acetamide, 2-methyl-benzoxazole and phenol. In addition, methanol, ethanol, acetic acid, methyl acetate and ethyl acetate were identified in the higher concentration samples. |
| De Witte, B., Van Langenhove, H., Demeestere, K., Saerens, K., De Wispelaere, P. and Dewulf, J. (2010) Ciprofloxacin ozonation in hospital wastewater treatment plant effluent: Effect of pH and H2O2. Chemosphere 78(9), 1142-1147. | Ciprofloxacin | The ozonation of ciprofloxacin was studied in hospital wastewater treatment plant effluent with focus on parent compound degradation, degradation product identification and residual antibacterial activity. Before ozonation, ciprofloxacin sorption on suspended solids was tested as a function of temperature (110.0-27.5 degrees C and pH (3, 7 and 10). Temperature did not significantly affect ciprofloxacin sorption while sorption was highest at pH 7 (log K-d = 4.7) compared to pH 3 (log K-d = 4.3) and 10 (log K-d = 3.9) (n = 3). Ozonation was slowest at pH 7 with ciprofloxacin half life times of 29 min, compared to 19 and 27 min at pH 10 and 3, respectively. Addition of 10-1000 mu M H2O2 increased ciprofloxacin half life times up to 38 min, probably influenced by competition with H2O2 for ozone as well as radical species. Ciprofloxacin ozonation products were identical as previously detected during ciprofloxacin ozonation in deionized water and revealed strong pH dependence. Residual antibacterial activity was measured by agar diffusion tests. For Pseudomonas fluorescens and Escherichia coli, reduction of antibacterial activity was related to the parent compound degradation, while degradation products indicated to be the main compounds with respect to the antibacterial activity against Bacillus coagulans. |
| An, T.C., Yang, H., Li, G.Y., Song, W.H., Cooper, W.J. and Nie, X.P. (2010) Kinetics and mechanism of advanced oxidation processes (AOPs) in degradation of ciprofloxacin in water. Applied Catalysis B-Environmental 94(3-4), 288-294. | Ciprofloxacin | Fluoroquinolones and their metabolites are found in surface and ground waters, indicating their ineffective removal by conventional water treatment technologies. Advanced oxidation processes (AOPs) are alternatives to traditional water treatments. They utilize free radical reactions to directly degrade fluoroquinolones. This work reports absolute rate constants for the reaction of ciprofloxacin with several free radicals, (OH)-O-center dot, N-center dot(3) and SO4 center dot- as well as hydrated electrons. Pulsed radiolysis experiments showed that (OH)-O-center dot, N-center dot(3) and e(aq)(-) reacted quickly with ciprofloxacin, with bimolecular reaction rate constants of (2.15 +/- 0.10) x 10(10), (2.90 +/- 0.12) x 10(10) and (2.65 +/- 0.15) x 10(10) M-1 s(-1), respectively. while the SO4 center dot- radical appeared not to react with ciprofloxacin. Transient spectra were observed for the intermediate radicals produced by hydroxyl and azide radical reactions. Moreover, ciprofloxacin can be degraded rapidly using a typical advanced oxidation process, TiO2 photocatalysis, with half-lives of 1.9-10.9 min depending upon pH values. Seven degradation products were elucidated by LC/MS/MS analysis, and the degradation mechanism of ciprofloxacin was also tentatively proposed by combining the experimental evidence with theoretical calculations of frontier electron densities. The calculations suggest that the addition of a hydroxyl radical to ciprofloxacin and photo-hole direct attack is two predominant reaction pathways. |
| Song, W.H., Cooper, W.J., Peake, B.M., Mezyk, S.P., Nickelsen, M.G. and O'Shea, K.E. (2009) Free-radical-induced oxidative and reductive degradation of N,N '-diethyl-m-toluamide (DEET): Kinetic studies and degradation pathway. Water Research 43(3), 635-642. | DEET | N,N'-Diethyl-m-toluamide (DEET) is widely used as an insect repellent and has therefore been detected as a contaminant in numerous waste and surface waters. in this study we have determined the absolute reaction rate constants of DEET with the hydroxyl radical and the hydrated electron in aqueous solution as (4.95 +/- 0.18) x 10(9) and (1.34 +/- 0.04) x 10(9) M (1) s (1), respectively, using pulse radiation. To provide additional information on the radicals formed upon oxidation, transient spectra were measured from 1 to 150 mu s, with transient decay rates determined from the time-dependence of the maximum absorption at 330 nm. These data suggest simple decay of the initially formed radical to stable products. Radical-based destruction mechanisms for destruction of DEET are proposed based on the LC-MS determination of the stable compounds produced by Co-60 gamma-irradiation of DEET solutions. These data will be useful in evaluating potential advanced oxidation/reduction processes for the control of DEET and understanding its fate and transport in surface water where analogous radical chemistry is operative. |
| Rivas, J., Gimeno, O., Encinas, A. and Beltran, F. (2009) Ozonation of the pharmaceutical compound ranitidine: Reactivity and kinetic aspects. Chemosphere 76(5), 651-656. | Ranitidine | Ranitidine has been ozonated under different operating conditions of pH, applied ozone dose, initial ranitidine concentration and presence or absence of free radical inhibitors. Results of ranitidine evolution with time indicate a high reactivity of this compound with molecular ozone. Mineralization levels achieved in the order of 20-25% suggest that the (CH3)(2)-N-CH2- moiety bonded to the furan ring could be separated from the rest of the ranitidine structure and further mineralized. Only alkaline conditions (pH = 11) are capable of increasing TOC conversion up to values close to 70%. Determination of the direct ozonation rate constant for ranitidine by means of competitive kinetics reveals an unacceptable dependence of the aforementioned constant with the reference compound reactivity. It is hypothesised that only reference compounds with reactivity similar to the target species should be used. |
| Puttaswamy and Shubha, J.P. (2009) Kinetics and Mechanism of Sodium N-halo-p-toluenesulfonamides Oxidation of Diclofenac in Alkaline Medium. Aiche Journal 55(12), 3234-3240. | Diclofenac | Diclofenac belongs to a class of drugs called nonsteroidal antiinffammatory drugs. The kinetics and mechanism of oxidation of diclofenac by sodium N-halo-p-toluenesulfonamides viz., chloramine-T and bromamine-T in NaOH medium have been studied at 293 K. Under comparable experimental conditions, reactions with both the oxidants follow identical kinetics with a first-order dependence on each (oxidant)(o) and a fractional-order dependence on each (diclofenac)o and [NaOH]. Activation parameters have been computed. N-hydroxyldiclofenac is identified as the oxidation product of diclofenac. Michaelis-Menten type of mechanism has been suggested. The rate of oxidation of diclofenac is about four-fold faster with bromamine-T when compared with chloramine-T. This may be attributed to the difference in electrophilicities of Cl+ and Br+ ions and also the van der Waal's radii of chlorine and bromine. Plausible mechanism and related rate law have been designed for the observed kinetics. |
| Kracun, M., Kocijan, A., Bastarda, A., Grahek, R., Plavec, J. and Kocjan, D. (2009) Isolation and structure determination of oxidative degradation products of atorvastatin. Journal of Pharmaceutical and Biomedical Analysis 50(5), 729-736. | Atorvastatin | Methods were developed for the preparation and isolation of four oxidative degradation products of atorvastatin. ATV-FX1 was prepared in the alkaline acetonitrile solution of atorvastatin with the addition of hydrogen peroxide. The exposition of aqueous acetonitrile solution of atorvastatin to sunlight for several hours followed by the alkalization of the solution with potassium hydroxide to pH 8-9 gave ATV-FXA. By the acidification of the solution with phosphoric acid to pH 3 ATV-FXA1 and FXA2 were prepared. The isolation of oxidative degradation products was carried out on a reversed-phase chromatographic column Luna prep C18(2) 10 mu m applying several separation steps. The liquid chromatography coupled with a mass spectrometer (LC-MS), high resolution MS (HR-MS), 1D and 2D NMR spectroscopy methods were applied for the structure elucidation. All degradants are due to the oxidation of the pyrrole ring. The most probable reaction mechanism is intermediate endoperoxide formation with subsequent rearrangement and nucleophilic attack by the 5-hydroxy group of the heptanoicfragment. ATV-FX1 is4-[1b-(4-Fluoro-phenyl)-6-hydroxy-6-isopropyl-1a-phenyl-6a-phenylcarba moyl-hexahydro-1,2-dioxa-5a-aza-cyclopropa[a]inden-3-yl]-3-(R)-hydroxy-b utyric acid and has a molecular mass increased by two oxygen atoms with regard to atorvastatin. ATV-FXA is the regioisomeric compound, 4-[6-(4-Fluoro-phenyl)-6-hydroxy-1b-isopropyl-6a-phenyl-1a-phenylcarbamo yl-hexahydro-1,2-dioxa-5a-aza-cyclopropa[a]inden-3-yl]-3-(R)-hydroxy-but yric acid. Its descendants ATV-FXA1 and FXA2 appeared without the atorvastatin heptanoic fragment and are 3-(4-Fluoro-benzoyl)-2-isobutyryl-3-phenyl-oxirane-2-carboxylic acid phenylamide and 4-(4-Fluorophenyl)-2,4-dihydroxy-2-isopropyl-5-phenyl-3,6-dioxa-bicyclo[ 3.1.0]hexane-1-carboxylic acid phenylamide, respectively. Quantitative NMR spectroscopy was employed for the assay determination of isolated oxidative degradation products. The results obtained were used for the determination of the UV response factors relative to atorvastatin. |
| Felis, E., Wiszniowski, J. and Miksch, K. (2009) Advanced Oxidation of Diclofenac in Various Aquatic Environment. Archives of Environmental Protection 35(2), 15-25. | Diclofenac | Many of the drugs used are not completely metabolized in the human body and with urine and faces are introduced into the sewage system. Finally, due to their incomplete removal during the conventional waste-water treatment process (CWTP), they call be released into the receiving water. One of the medicaments frequently detected in surface water is diclofenac. The present Study addresses the problem) of diclofenac removal in various aquatic samples using advanced oxidation processes (AOPs). The experiments were performed in distilled water and in biologically treated wastewater. The following AOPs were applied: Fenton's reagent, UV-and UV/H2O2-processes. The concentration of diclofenac in distilled water corresponded to the concentration of this drug in human urine (ca. 20 mg-dm(-3)). The real wastewater samples contained diclofenac concentrations ranging from 630 to 790 ng.dm(-3). The photodegradation of diclofenac was carried Out ill the photoreactor with a medium pressure Hg-vapor lamp (400 W). In the Fenton's reaction different( molar ratios-of H2O2/Fe2+ were used. The diclofenac; mineralization (TOC removal) strictly depended on the amount of H2O2 applied in the Fenton's reaction. Diclofenac was rapidly degraded by direct photolysis (UV) and in UVA-H2O2 process both in distilled water and in wastewater samples. The results proved that the advanced oxidation processes are effective in diclofenac removal from aquatic samples. The Pseudo first order rate constants for diclofenac photodegradation were determined. |
| DellaGreca, M., Iesce, M.R., Pistillo, P., Previtera, L. and Temussi, F. (2009) Unusual products of the aqueous chlorination of atenolol. Chemosphere 74(5), 730-734. | Atenolol | The reaction of the drug atenolol with hypochlorite under conditions that simulate wastewater disinfection was investigated. The pharmaceutical reacted in 1 h yielding three products that were separated by chromatographic techniques and characterized by spectroscopic features. Two unusual products 2-(4-(3-(chloro(2-chloropropan-2-yl)amino)-2-hydroxypropoxy)phenyl) acetamide and 2-(4-(3-formamido-2-hydroxypropoxy)phenyl) acetamide were obtained along with 2-(4-hydroxyphenyl) acetamide. When the reaction was stopped at shorter times only 2-(4-(3-amino-2-hydroxypropoxy)phenyl) acetamide and the dichlorinated product were detected. Tests performed on the seeds of Lactuca sativa show that chlorinated products have phytotoxic activity |
| De Witte, B., Dewulf, J., Demeestere, K. and Van Langenhove, H. (2009) Ozonation and advanced oxidation by the peroxone process of ciprofloxacin in water. Journal of Hazardous Materials 161(2-3), 701-708. | Ciprofloxacin | A bubble reactor was used for ozonation of the antibiotic ciprofloxacin. Effects of process parameters ozone inlet concentration, ciprofloxacin concentration, temperature, pH and H2O2 concentration were tested. Desethylene ciprofloxacin was identified, based on HPLC-MS analysis, as one of the degradation products. Formation of desethylene ciprofloxacin was highly dependent on pH, with the highest concentration measured at pH 10. Radical scavengers t-butanol and parachlorobenzoic acid were added in order to gain mechanistic understanding. Radical species other than hydroxyl radicals were suggested to occur at acidic pH which can explain fast ciprofloxacin ozonation at pH 3. |
| Coelho, A.D., Sans, C., Aguera, A., Gomez, M.J., Esplugas, S. and Dezotti, M. (2009) Effects of ozone pre-treatment on diclofenac: Intermediates, biodegradability and toxicity assessment. Science of the Total Environment 407(11), 3572-3578. | Diclofenac | Diclofenac (DCF), a common analgesic, anti-arthritic and anti-rheumatic drug, is one of the most frequently detected compounds in water. This study deals with the degradation of diclofenac in aqueous solution by ozonation. Biodegradability (BOD5/COD ratio and Zahn-Wellens test), acute ecotoxicity and inhibition of activated sludge activity were determined in ozonated and non-ozonated samples. Liquid chromatography coupled with time-of-flight mass spectrometry (LC/TOF-MS) was used to identify the intermediates formed in 1 h of ozonation. Eighteen intermediates were identified by these techniques and a tentative degradation pathway for DCF ozonation is proposed. Experimental results show that ozone is efficient at removing DCF: >99% removal (starting from an initial concentration of 0.68 mmol L-1) was achieved after 30 min of ozonation (corresponding to an absorbed ozone dose of 0.22 g L-1, which is 4.58 mmol L-1). However, only 24% of the substrate was mineralized after 1 h of ozonation. The biodegradability, respiration inhibition in activated sludge and acute toxicity tests demonstrate that ozonation promotes a more biocompatible effluent of waters containing DCF. |
| Vikesland, P.J., Rule, K.L., Greyshock, A.E., Ebbett, V.R. and Fiss, E.M. (2006) Triclosan Reactivity in Chlorinated and Monochloaminated Waters, AWWARF, Denver CO. #91134 | Triclosan |
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| Anderson, P., Denslow, N., Drewes, J.E., Olivieri, A., Schlenk, D., Scott, G.I. and Snyder, S. (2012) Monitoring Strategies for Chemicals of Emerging Concern (CECs) in California's Aquatic Ecosystem, Costa Mesa, CA. |
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Diamond, J., Thornton, K., Munkittrick, K., Kidd, K., Bartell, S. and Kapo, K. (2011) Diagnostic Tools to Evaluate Impacts of Trace Organic Compounds, Water Environment Research Foundation, Alexandria, VA. |
With the recent advent of improved analytical and biomarker detection capabilities, a variety of organic chemicals have been found in trace amounts (Trace Organic Chemicals, TOrCs) in surface waters and fish tissue. TOrCs include pharmaceuticals, personal care products, surfactants, pesticides, flame retardants, and other organic chemicals, some with unknown modes of action or effects. Identifying or predicting ecological effects of TOrCs in typical aquatic multi-stressor situations is challenging, requiring a variety of epidemiological tools that together, can diagnose effects at multiple scales of ecological organization. The goal of this research is to provide information on TOrCs to help the water quality community make scientifically defensible and cost effective decisions that are appropriately protective of aquatic populations and communities. Five objectives were addressed in this research: 1) develop and apply a procedure to prioritize which TOrCs are of most concern; 2) develop and test a conceptual site screening framework to determine if sites are or could be affected by TOrCs; 3) evaluate and test diagnostic approaches to identify potential risks due to TOrCs using various case studies; 4) develop a relational database and user interface with which the water resource community can enter, store, and search TOrC exposure and occurrence data in the U.S.; and 5) foster partnerships and transfer knowledge gained in this research to the water quality community. TOrC fate, effects, and occurrence data were compiled in a database for over 500 organic chemicals based on over 100 published studies representing more than 50 organizations and 700 sites. Alternative risk-based prioritization processes and draft lists of high priority TOrCs were developed. A preliminary site screening and diagnostic framework was developed and evaluated using seven different case study sites. EPA’s causal analysis (stressor identification) procedures, Canada’s Environmental Effects Monitoring (EEM) procedure, the ecosystem model CASM (Comprehensive Aquatic System Model), and several other specialized diagnostic tools were used and evaluated. A relational database based on Tetra Tech’s EDAS2 was developed using the Microsoft platform. The modified version of EDAS2, built on the EPA WQX data model, provides web-based data queries using a combination of tabular data for downloads and a visual map interface that allows the user to view, query, and select sites from the map having chemical or biological data. This final report summarizes all approaches used and results obtained in this research; discusses critical data gaps and other important uncertainties, and provides testable hypotheses and recommendations for Phase 2 testing and analyses. | |
| Snyder, S.A., Vanderford, B.J., Drewes, J.E., Dickenson, E., Snyder, E.M., Bruce, G.M. and Pleus, R.C. (2008) State of Knowledge of Endocrine Disruptors and Pharmaceuticals in Drinking Water, AWWA Research Foundation, Denver, CO. | ||