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Chromatographic procedures such as solid phase extraction and high performance liquid chromatography coupled with a fluorescence detector (SPE-HPLC-FLD), were carried out to determine the concentrations of the surfactant nonylphenol ethoxylate (9 ethylene oxide units, NP9EO) and its biodegradation product, 4-nonylphenol (NP), in samples collected from the wastewater treatment system at the University Hospital (HUSM) of the Federal University of Santa Maria. The results showed a high concentration of NP9EO in all the collected samples (0.075 - 4.12 mg L(-1)) and an almost complete absence of NP. In addition, electrocoagulation (EC) of NP9EO was carried out in aqueous solution and in the HUSM effluent. A NP9EO removal rate of 95 % was achieved from the aqueous solution, following a pseudo-first-order kinetics. Through LC-MS measurements in aqueous solutions, it was possible to determine the formation of short-chain nonylphenol ethoxylate (NPEO), such as nonyl-phenoxy acetic acid (NP1EC), after 30 min of EC. In the case of the HUSM wastewater, the NP9EO removal was 89 %, and the chemical oxygen demand (COD) abatement was 26 %. A respirometric test was conducted to measure the increase of biodegradability during the EC and the aqueous samples were found to be less readily biodegradable before the 30-min period of electrocoagulation than after it had been completed.

This study was carried out to evaluate the occurrence of the fluoroquinolone antimicrobial agent ciprofloxacin (CIP) in the effluent of the Hospital of the Federal University of Santa Maria (HUSM). Measured environmental concentrations (MECs) of CIP in the hospital wastewater, both before (P1) and after (P2) cesspit/filter system treatment (CFTS), were determined by means of solid phase extraction and reversed-phase liquid chromatography with fluorescence detection (LC-FLD) and reversed-phase liquid chromatography with mass spectrometric detection (LC-MS/MS). The MECs (n = 7 daily composed samples) were 19 to 155 μg L–1 (average: 54 ± 21 μg L–1) and 32 to 99 μg L–1 (average: 65 ± 45 μg L–1) in P1 and P2, respectively. No relevant removal was observed from P1 to P2. In a worst case scenario, the final effluent was regarded as MECs of surface water. These MECs were generally 5 to 20,000-fold higher than what was previously known. If the present data is drawn on to form a model of the situation in developing countries, the picture provides a first rough indication that the environmental risk associated with the use and emission of pharmaceuticals into the environment in developing countries might be higher than in developed countries. This study was carried out to evaluate the occurrence of the fluoroquinolone antimicrobial agent ciprofloxacin (CIP) in the effluent of the Hospital of the Federal University of Santa Maria (HUSM). Measured environmental concentrations (MECs) of CIP in the hospital wastewater, both before (P1) and after (P2) cesspit/filter system treatment (CFTS), were determined by means of solid phase extraction and reversed-phase liquid chromatography with fluorescence detection (LC-FLD) and reversed-phase liquid chromatography with mass spectrometric detection (LC-MS/MS). The MECs (n = 7 daily composed samples) were 19 to 155 μg L–1 (average: 54 ± 21 μg L–1) and 32 to 99 μg L–1 (average: 65 ± 45 μg L–1) in P1 and P2, respectively. No relevant removal was observed from P1 to P2. In a worst case scenario, the final effluent was regarded as MECs of surface water. These MECs were generally 5 to 20,000-fold higher than what was previously known. If the present data is drawn on to form a model of the situation in developing countries, the picture provides a first rough indication that the environmental risk associated with the use and emission of pharmaceuticals into the environment in developing countries might be higher than in developed countries.

In this study, a semi-micro procedure for the COD (Chemical Oxygen Demand) was undertaken to allow the measurement of effluent samples with a high chloride content. It was found that the COD values for standard and effluent samples, corresponded closely to those obtained using the standard method of Burns and Marshall. When the method was applied to samples of industrial wastewater, with a very high chloride content, the recommended procedure proved to be accurate and precise, with RSDs of 6% and 4.3% for the standard and effluent solutions, respectively. The required amount of hazardous reagents was similar to that found in the standard closed reflux method. It was also possible to determine the total amount of oxidized halides. The use of this low-cost, laboratory-made system made it unnecessary to acquire an expensive, imported analytical system, while maintaining a high level of accuracy in the determinations.

This study investigated the degradation of nonylphenol polyethoxylate (9 ethylene oxide unities, NP9EO) in aqueous solution and textile wastewater by electrocoagulation (iron and aluminum electrodes) and electrochemical Fenton. The studied processes had as parameters NP9EO concentration (measured by HPLC), chemical oxygen demand (COD), integrated absorbance (200–800 nm) and hydrogen peroxide concentration (H2O2). First, it was determined the NP9EO concentration in textile wastewater by means of a modified procedure based on the extraction of surfactants. A factorial design 24 was employed to optimize the experimental conditions for NP9EO degradation in aqueous solution by electrocoagulation, through the following variables: NP9EO concentration, applied current, temperature and electrode material. The use of aluminum electrodes brought the most significant effects. The best performance was achieved by experiments using 20 mg L−1 aqueous NP9EO, 1.5 A and aluminum electrodes (around 95% removal in 30 min). The best experimental conditions achieved using factorial design were applied to textile wastewater treatment. The electrocoagulation using Al-electrodes allowed the NP9EO degradation and COD reduction of 95 and 50%, respectively, in only 15 min treatment. In order to enhance the aqueous NP9EO degradation obtained by electrocoagulation with iron electrodes, electrochemical Fenton was also performed and 95% NP9EO removal was achieved in 5 min (aqueous solution) and 10 min (wastewater) treatment, respectively. Besides the organic load removal (COD reduction) having not surpassed 55% in both processes, the total NP9EO removal of the textile wastewater was equally efficient by both aqueous solution and textile wastewater treatment (causing almost total degradation).

Hospital effluents are serious problems in developing countries like Brazil, and when not treated adequately, can cause mutagenic effects on live organisms. Biomonitors, like Allium cepa L., which is one of the most used plant species when monitoring effluent genotoxicity, have been used to alert the world population about environmental contamination and genotoxic chemical emissions. The Allium cepa test was used to evaluate the genotoxicity of a hospital effluent in Santa Maria, Rio Grande do Sul State, Brazil. During the study, chromosomal disruptions, anaphasic bridges, and micronuclei during telophase were observed, indicating environmental toxicity risk. © 2009 Springer Science+Business Media, LLC.

There are several papers in the literature that have recorded satisfactory results for the degradation of different pharmaceuticals in aqueous solutions by means of oxidation processes; however, only a few of them relied on real samples in carrying out their investigations. This study examines the results of the performance of photo-induced oxidation, heterogeneous photocatalysis, ozonation and peroxone in degrading the fluoroquinolone antimicrobial ciprofloxacin (CIP) in a hospital effluent. The real samples were collected from the treatment system of the University Hospital of Santa Maria (HUSM). Liquid chromatography with fluorescence detection (LC-FLD) was used to monitor the decrease of the CIP concentration. As expected, photo-induced oxidation was much slower than the other processes in bringing about total CIP degradation. Both heterogeneous photocatalysis and peroxone led to almost complete CIP degradation after 60 min treatment. Ozonation showed the best performance: total degradation after 30 min treatment. This was an unexpected result in view of the greater capacity of the other two processes to generate hydroxyl radicals. However, this finding supports a result in the literature that has tended to be overlooked. The by-products formed during the application of the processes were found to be very similar. Moreover, on the basis of the data obtained from the literature, there is some evidence to suggest that the by-products are derived from the oxidation of the piperazine group. There are several papers in the literature that have recorded satisfactory results for the degradation of different pharmaceuticals in aqueous solutions by means of oxidation processes; however. only a few of them relied on real samples in carrying out their investigations. This study examines the results of the performance of photo-induced oxidation, heterogeneous photocatalysis, ozonation and peroxone in degrading the fluoroquinolone antimicrobial ciprofloxacin (CIP) in a hospital effluent. The real samples were collected from the treatment system of the University Hospital of Santa Maria (HUSM). Liquid chromatography with fluorescence detection (LC-FLD) was used to monitor the decrease of the CIP concentration. As expected, photo-induced oxidation was much slower than the other processes in bringing about total CIP degradation. Both heterogeneous photocatalysis and peroxone led to almost complete CIP degradation after 60 min treatment. Ozonation showed the best performance: total degradation after 30 min treatment. This was an unexpected result in view of the greater capacity of the other two processes to generate hydroxyl radicals. However, this finding supports a result in the literature that has tended to be overlooked. The by-products formed during the application of the processes were found to be very similar. Moreover, on the basis of the data obtained from the literature, there is some evidence to suggest that the by-products are derived from the oxidation of the piperazine group. (C) 2009 Elsevier B.V. All rights reserved

Photo-treatment for the removal of pharmaceuticals in effluents is a topic currently under discussion. In some countries effluents from hospitals are directly emitted into open ditches without any further treatment and with very little dilution. Under such circumstances photo-degradation in the environment can occur. However, photo-degradation does not necessarily end up with the complete mineralization of a chemical. Therefore, photo-product biodegradability and toxicity against environmental bacteria is of interest. Hospital effluents have often a pH around 9. Therefore, photo-oxidation (150W medium-pressure Hg-lamp, batch reactor) of ciprofloxacin (CIP) was studied at pH 9. The primary elimination of CIP was monitored and structures of photo-products were assessed by liquid chromatography ion trap mass spectrometry (LC-MS/MS). Five compounds were identified as probable products of photo-defluorination, -decarboxylation and loss of the piperazine moiety. These photo-products were not biodegradable in the Closed Bottle test - OECD 301D. They did not affect Vibrio fisheri in the applied concentrations. Photo-treatment for the removal of pharmaceuticals in effluents is a topic currently under discussion. In some countries effluents from hospitals are directly emitted into open ditches without any further treatment and with very little dilution. Under such circumstances photo-degradation in the environment can occur. However, photo-degradation does not necessarily end up with the complete mineralization of a chemical. Therefore, photo-product biodegradability and toxicity against environmental bacteria is of interest. Hospital effluents have often a pH around 9. Therefore, photo-oxidation (150 W medium-pressure Hg-lamp, batch reactor) of ciprofloxacin (CIP) was studied at pH 9. The primary elimination of CIP was monitored and structures of photo-products were assessed by liquid chromatography ion trap mass spectrometry (LC–MS/MS). Five compounds were identified as probable products of photo-defluorination, -decarboxylation and loss of the piperazine moiety. These photo-products were not biodegradable in the Closed Bottle test – OECD 301D. They did not affect Vibrio fisheri in the applied concentrations.

The treatment of an effluent from the production of trifluraline was studied using a 1-L, semi-batch, tank-stirred glass reactor for performing three different advanced oxidation processes (photoperoxidation, Fenton, photo-Fenton). A commercial, medium-pressure mercury lamp was used for sample irradiation. The degradation was monitored by measurements of absorptiometric color reduction, UV-visible absorption spectra, and chemical oxygen demand (COD). The obtained results showed that the photo-Fenton process was the most effective treatment for the trifluraline effluent. The treatment of an effluent from the production of trifluraline was studied using a 1-L, semi-batch, tank-stirred glass reactor for performing three different advanced oxidation processes (photoperoxidation, Fenton, photo-Fenton). A commercial, medium-pressure mercury lamp was used for sample irradiation. The degradation was monitored by measurements of absorptiometric color reduction, UV-visible absorption spectra, and chemical oxygen demand (COD). The obtained results showed that the photo-Fenton process was the most effective treatment for the trifluraline effluent.

The effluent stream from the industrial production of the herbicide trifluraline (amination water) was submitted to a combined treatment of a physical–chemical process (coagulation) with an advanced oxidation process (Fenton). The recovering of the residual sludge was performed. The combined coagulation–Fenton-sedimentation process proved to be very suitable for wastewater color reduction (91.6%), promoting considerable abatement of the organic load (63.4% COD reduction). According to the fractionary factorial design, the main effects of pH (A) and Fenton sludge (B) variables were considered statistical fluctuations of the process (and not decisive), while the main effects of Fe3+ (C), Fe2+ (D) and H2O2 (E), as well as the interactions between variables A and B, A and E, C and D and C and E were considered significant. The obtained results suggest that the combined process can be advantageous for the treatment of recalcitrant industrial effluents, such as the amination water from the trifluraline production.

Chitosan, a natural polysaccharide obtained from chitin deacetylation, complexes with metal ions by coordination with the free electron pairs of amine groups. Based on this complexation mechanism, cross-linked chitosan-metal microparticles were prepared by spray drying using iron (II or III) or zinc ions and characterized in terms of size distribution and capacity to specifically adsorb ciprofloxacin. Chitosan-Zn(II) and chitosan-Fe(III) microparticles appear to adsorb more ciprofloxacin than plain chitosan or chitosan-Fe(II) microparticles. Adsorption isotherms for CH and CH–Fe(II) microparticles can be fitted by a single logarithm model (slope 1) with one ciprofloxacin per adsorption site, whereas for CH–Fe(II) and CH–Zn(II) microparticles, isotherms are bilogarithmic with an initial slope of 2, suggesting that a single adsorption site can bind two molecules of ciprofloxacin. In addition, the pseudo second order kinetic model fits well experimental data, proving that adsorption is mediated by a chemical reaction. CH–Fe(II) and CH–Zn(II) appear very promising for drug elimination, either from hospital waste water or from the gastrointestinal tract to prevent the emergence of antibiotic resistance. Chitosan, a natural polysaccharide obtained from chitin deacetylation, complexes with metal ions by coordination with the free electron pairs of amine groups. Based on this complexation mechanism, cross-linked chitosan-metal microparticles were prepared by spray drying using iron (II or III) or zinc ions and characterized in terms of size distribution and capacity to specifically adsorb ciprofloxacin. Chitosan-Zn(II) and chitosan-Fe(III) microparticles appear to adsorb more ciprofloxacin than plain chitosan or chitosan-Fe(II) microparticles. Adsorption isotherms for CH and CH–Fe(II) microparticles can be fitted by a single logarithm model (slope 1) with one ciprofloxacin per adsorption site, whereas for CH–Fe(II) and CH–Zn(II) microparticles, isotherms are bilogarithmic with an initial slope of 2, suggesting that a single adsorption site can bind two molecules of ciprofloxacin. In addition, the pseudo second order kinetic model fits well experimental data, proving that adsorption is mediated by a chemical reaction. CH–Fe(II) and CH–Zn(II) appear very promising for drug elimination, either from hospital waste water or from the gastrointestinal tract to prevent the emergence of antibiotic resistance.