Quantification of pharmaceuticals in hospital effluent: Weighted ranking of environmental risk using a fuzzy hybrid multicriteria method.

An analytical method for quantification of seventeen pharmaceuticals and one metabolite was validated and applied in the analysis of hospital effluent samples. Two different sampling strategies were used: seasonal sampling, with 7 samples collected bimonthly; and hourly sampling, with 12 samples collected during 12 h. Thus, the variability was both seasonal and within the same day. High variability was observed in the measured concentrations of the pharmaceuticals and the metabolite. The quantification method, performed using weighted linear regression model, demonstrated results of average concentrations in seasonal samples ranged between 0.19 µgL-1 (carbamazepine) and higher than 61.56 µgL-1 (acetaminophen), while the hourly samples showed average concentrations between 0.07 µgL-1 (diazepam) and higher than 54.91 µgL-1 (acetaminophen). It is described as higher because the maximum concentration of the calibration curve took into account the dilution factor provided by DLLME. The diurnal results showed a trend towards higher concentrations in the first and last hours of sampling. The risk quotient (RQ) was calculated using organisms from three different trophic levels, for all the analytes quantified in the samples. Additionally, in order to understand the level of importance of each RQ, an expert panel was established, with contributions from 23 specialists in the area. The results were analyzed using a hybrid decision-making approach based on a Fuzzy Analytic Hierarchy Process (FAHP) and the Technique for Order Preference by Similarity to Ideal Solution (TOPSIS) method, in order to rank the compounds by environmental risk priority. The compounds of greatest concern were losartan, acetaminophen, 4-aminoantipyrine, sulfamethoxazole, and metoclopramide. Comparison of the environmental risk priority ranking with the potential human health risk was performed by applying the same multicriteria approach, with the prediction of endpoints using in silico (Q)SAR models. The results obtained suggested that sulfamethoxazole and acetaminophen were the most important analytes to be considered for monitoring.

Classifying micropollutants by environmental risk in groundwater using screening analysis associated to a hybrid multicriteria method combining (Q)SAR tools, fuzzy AHP and ELECTRE.

This study aimed to evaluate and monitor pesticides in groundwater of the Serra Geral aquifer, located in the Paraná Basin 3 (southern Brazil), using Liquid Chromatography coupled with a Quadrupole-Time-of-Flight Mass Spectrometer (LC-QTOF MS). A total of 117 samples, collected in three different moments, were analyzed over 36 months. Groundwater samples from 35 wells and four surface water points were monitored in each sampling campaign. A pesticide screening methodology was proposed with the tentative identification of 1607 pesticides and pesticide metabolites. The application of the proposed methodology resulted in the verification of 29 pesticides and pesticide metabolites, 7 as confirmed analytes and 22 as suspect compounds. (Q)SAR in silico predictions and GUS index calculation provided data on the potential environmental risk of the identified compounds, with eight endpoints considered. After in silico predictions, an alternative hybrid multicriteria method was applied, combining the weighting of endpoints of fuzzy AHP and micropollutants classification by environmental risk using ELECTRE. The fuzzy AHP results indicated the greatest importance of mutagenicity among the eight evaluated indicators, while the scarce influence of the physicochemical properties on the environmental risk suggested their exclusion from the model. Accordingly, the ELECTRE results highlighted the prevalence of thiamethoxam and carbendazim as the most dangerous for the environment. The application of the proposed method enabled the selection of the compounds that must be monitored, considering mutagenicity and toxicity predictions for environmental risk analysis.

Influence of water matrix components and peroxide sources on the transformation products and toxicity of tebuthiuron under UVC-based advanced oxidation processes.

Coupling of UV-C irradiation to different peroxides (H2O2, S2O82- and HSO5-) has great potential to degrade persistent organic compounds due to the formation of HO• or SO4•- species. However, an in-depth comparison between the performance of different UV-C/peroxide processes as a function of (i) target compound degradation, (ii) generated transformation products and (iii) lethal/sub lethal toxicity effects has not yet been performed. To this end a comparison study was carried out to evaluate the effectiveness of different UV-C/peroxide processes using the herbicide tebuthiuron (100 or 500 µg L-1) as a model pollutant. TBH degradation experiments were performed at lab-scale in real municipal wastewater treatment plant effluent and distilled water. Faster degradation occurred by increasing peroxide concentration from 735 to 2206 µmol L-1 in the municipal wastewater treatment plant effluent, mainly for S2O82-. Experiments performed in the presence of peroxide trapping agents - HO• and SO4•- (methoxibenzene) or HO• (2-propanol) - revealed that oxidation in the UV-C/S2O82- system occurs mainly through SO4•-. Lower toxicity for the MWWTP effluent was obtained after oxidative treatments using hydrogen peroxide or monopersulfate as oxidants which react mainly through HO• radicals. Two mechanistic pathways were proposed for tebuthiuron degradation: (i) hydrogen abstraction by HO• (H2O2 and HSO5-) and (ii) electron transfer by SO4•- (S2O82-). In addition, one unprecedented transformation product was identified. In conclusion, results emphasize the relevance of comparing the degradation of toxic compounds in the presence of different peroxide sources and matrices and simultaneouly evaluating responses chemical and biological endpoints.

Miniaturized Method for Chemical Oxygen Demand Determination Using the PhotoMetrix PRO Application.

The analysis of chemical oxygen demand (COD) plays an important role in measuring water pollution, but it normally has a high ecological price. Advances in image acquisition and processing techniques enable the use of mobile devices for analytical purposes. Here, the PhotoMetrix PRO application was used for image acquisition and multivariate analysis. Statistical analysis showed no significant difference in the results compared to the standard method, with no adverse effect of the volume reduction. The cost of analysis and waste generation were reduced by one third, while the analysis time was reduced by one fifth. The miniaturized method was successfully employed in the analysis of several matrices and for the evaluation of advanced oxidation processes. The AGREE score was improved by 25% due to miniaturization. For these reasons, the miniaturized PhotoMetrix PRO method is a suitable option for COD analysis, being less hazardous to the environment due to reductions in the chemicals used and in waste generation.

Qualitative evaluation of pharmaceuticals and metabolites in hospital effluent: Influence of sample preparation technique and outranking by environmental risk using the ELECTRE method.

The presence of pharmaceuticals and metabolites in effluents has become a serious environmental problem, so it is essential to be able to monitor these microcontaminants using qualitative approaches, as well as to assess the potential environmental risks that such compounds may present. Therefore, in this study, suspect screening analysis was performed of 2030 pharmaceuticals and metabolites in hospital effluent samples, applying different sample preparation techniques. Additionally, a pioneering association of (Q)SAR assessment of identified contaminants with the ELECTRE multi-criteria decision analysis technique made it possible to prioritize analytes according to their environmental risk, in order to enable their inclusion in environmental monitoring programs. The results showed that the most advantageous alternative sample preparation technique consisted of cleanup (100 mg of silica/alumina sorbent) + dispersive liquid-liquid microextraction (7.5 of aqueous matrix, 325 µL of chloroform (extracting solvent), and 500 µL of acetonitrile as dispersing solvent). This procedure resulted in the identification of 70 pharmaceuticals and metabolites in the composite sample tested. The suspect screening analysis found a total of 105 microcontaminants, 28 of them being "confirmed compounds" and 77 being "suspect compounds". Of the compounds identified, 87% were pharmaceuticals and 13% were metabolites. The compounds identified were subsequently evaluated using different open access software packages, considering eight endpoints: mobility, persistence, estrogen receptor binding, wastewater treatment plant total removal, biodegradability, PBT (persistent, bioaccumulation and toxic), mutagenicity, and carcinogenicity. The (Q)SAR prediction results were used as input data for the ELECTRE outranking method. Categorization of the identified compounds by ELECTRE resulted in the kernel (priority compounds) and a further 19 groups. ELECTRE sensitivity evaluation indicated that for all the cases, the kernel and the following two groups coincided. The categorization provided by the ELECTRE method constitutes a highly intuitive decision and choice tool, which can assist in the selection of compounds if subsequent quantitative analysis is to be carried out.

Trends in Fenton and photo-Fenton processes for degradation of antineoplastic agents in water matrices: current knowledge and future challenges evaluation using a bibliometric and systematic analysis.

Antineoplastic agents present potential hazards to human health and the environment. For this reason, these compounds have attracted a great deal of attention from researchers in the environmental sciences field. In order to help guide future research, it is important to understand the current state of investigation of the occurrence of these microcontaminants and methods for their removal, especially focusing on Fenton and photo-Fenton processes applied to various aqueous matrices in which this class of pharmaceuticals is present. For this purpose, a systematic review of these topics was performed by bibliometric analysis of articles published during the last decade and available in the Scopus and Web of Science databases. This study enables visualization of the current panorama and trends in this field, providing a guide for future collaborative research and exchange of knowledge. Various strategies have been suggested to improve the efficiency of Fenton and photo-Fenton processes, mainly by means of the application of multiples additions of iron, the use of heterogeneous catalysts, and/or the use of chelating agents. Some studies have evaluated different radiation sources employed for photo-Fenton processes, such as solar and/or artificial radiation. In turn, the identification of transformation products generated by Fenton and photo-Fenton treatments, together with their evaluation by in silico (Q)SAR predictions or experimental toxicological bioassays, are related subjects that have been less reported in published works and that should be studied in depth. These subjects can support treatment evaluations that are more realistic, considering their limitations or potentials.

Multi-criteria decision-making techniques associated with (Q)SAR risk assessment for ranking surface water microcontaminants identified using LC-QTOF MS.

Contaminants of emerging concern (CECs) have been a focus of study for years, with investigations revealing the contamination of different environmental matrices (surface water, soil, air, and sediment) by diverse classes of microcontaminants. Understanding the contamination profiles requires identification and risk assessment of the microcontaminants. In the present work, analysis was made of the presence of 3250 compounds in 27 samples from the Conceição River (Rio Grande do Sul State, Brazil), using an SPE-LC-QTOF MS method. In total, 150 microcontaminants (confirmed and suspected) of different classes, especially pesticides and pharmaceuticals, were identified by an initial qualitative analysis. Subsequently, in silico predictions of eight endpoints, using quantitative structure-activity relationship ((Q)SAR) models, were employed to determine the risk of each previously screened microcontaminant. This large amount of (Q)SAR data, frequently with conflicting information in relation to the responses of the different endpoints, makes it difficult to define which microcontaminants should be prioritized for analysis. Therefore, in order to rank the identified microcontaminants by risk assessment, two multi-criteria decision-making (MCDM) ranking techniques (ToxPi and TOPSIS), associated with a weighting method, were performed to establish the order of priority for further quantitative analysis of the most hazardous microcontaminants. The two rankings were statistically similar, especially for the 20 highest priority microcontaminants. Nonetheless, sensitivity tests carried out for the ToxPi and TOPSIS outputs showed higher performance robustness of TOPSIS, compared to ToxPi. This is the first time that such an approach (screening/(Q)SAR/MCDM methods) has been performed in the context of microcontaminant environmental risk evaluation and demonstrated to be an available strategy to help rank the most concern microcontaminants identified in aqueous environment samples.

Degradation of pharmaceuticals in wastewater matrices through solar light-driven photocatalyst prepared from petrochemical waste.

Pharmaceuticals, such as dipyrone (DIP), paracetamol (PCT), and propranolol (PPN), are widely used analgesics and beta-blockers with the greatest presence in wastewaters and, consequently, in natural waters. The present work evaluated solar light-driven photocatalyst from petrochemical industrial waste (PW) as a strategy for the degradation of three pharmaceuticals in different water matrices (distilled water-DW, simulated wastewater-SWW, and real hospital wastewater-RHWW). All experiments were carried out in a solar photo-reactor with a capacity of 1 L and the experimental condition employed was a catalyst concentration of 350 mg L-1 at pH 5.0; these conditions were selected considering the Doehlert design validation spreadsheet and the desirability function. All materials prepared were conveniently characterized by zeta potential, small-angle X-ray scattering (SAXS), diffuse reflectance ultraviolet-visible (DRUV), and infrared spectroscopy. According to the results of the characterization, significant differences have been observed between the PW and the photocatalyst such as vibrational modes, optical absorption gap, and acid-basic characteristics on the surface, which suggests the potential use of the photocatalyst in the degradation of contaminants of emerging concern. Based on pharmaceutical degradation, DIP showed the highest photosensitivity (87.5%), and therefore the highest photocatalytic degradation followed by PPN; both compounds achieved final concentrations below the limit of quantification of the chromatographic method in DW. However, PCT was the most recalcitrant pharmaceutical in all matrices. Radicals from chromophoric natural organic matter (NOM) could improve PCT degradation in the SWW matrix (56%). Nevertheless, the results in RHWW showed a matrix effect with decreased the oxidation percentages (DIP-99%; PPN-71%; PCT-17%); hence, the addition of an oxidant such as H2O2 was studied as a pharmaceutical oxidation boost in RHWW. PPN was the molecule most sensitive to this strategy of oxidation (98%). Furthermore, 20 transformation products (TPs) generated throughout the treatment were identified by LC-QTOF MS using a customized TPs database. According to quantitative structure activity relationship (Q)SAR analysis, more than 75% of the TPs identified were not biodegradable. About 35% of them have oral toxicity characteristics indicated by Cramer's rules, and the DIP TPs represent high toxicity for different trophic levels.

Tube-in-tube membrane photoreactor as a new technology to boost sulfate radical advanced oxidation processes.

This work proposes a tube-in-tube membrane photoreactor, operated in a continuous-mode, to boost the efficiency of peroxydisulfate (PDS), through the photolytic (UV-C radiation) and photocatalytic (TiO2-P25) processes. This new technology can efficiently facilitate the transportation of PDS to the catalyst surface and water to be treated. The ultrafiltration tubular ceramic membrane was used as support for the TiO2-P25 and oxidant-catalyst/water contactor. Tests were performed using a synthetic solution and a municipal secondary effluent, both spiked with a pharmaceutical mix solution (paracetamol (PCT), furosemide (FRS), nimesulide (NMD), and diazepam (DZP); 200 µg L-1 of each). At steady-state regime, the UVC/S2O82-/TiO2 system, with radial PDS addition, showed the highest removal of pharmaceuticals in both matrices. Furthermore, twenty-two transformation products (TPs) were identified by applying LC-QTOF MS technique. Hence, the transformation pathways including hydroxylation in aromatic moiety by an electrophilic attack, electron transfer reactions, cleavage of C-O, C-N bond, H-abstraction and ring opening were proposed. TPs chemical structures were evaluated by in silico (Q)SAR approach using TOXTREE and EPI Suite™ software.

Chemical and toxicological evaluation along with unprecedented transformation products during photolysis and heterogeneous photocatalysis of chloramphenicol in different aqueous matrices.

As the presence of antibiotics in environmental waters enhances antimicrobial resistance, photolysis and heterogeneous photocatalysis of chloramphenicol (CAP) were evaluated in deionized water (DW) and in sewage treatment plant (STP) effluent under black light and solar irradiation. Processes were compared in terms of CAP degradation, reaction kinetics, and electrical energy per order, as well as regarding theoretical toxicity, biodegradability, carcinogenicity, and mutagenicity of transformation products (TPs). Rate constants obtained under photolysis (0.008 min-1) and heterogeneous photocatalysis (0.18 min-1) only differed in DW. This is due to the generation of photo-active reactive oxygen species (HO· and HO2·-/O2·-) under photolysis in STP effluent, as verified by experiments in the presence of 2-propanol and chloroform. Natural organic matter and HCO3- were the main responsible for reducing CAP degradation in STP effluent. Fifteen TPs were identified during both processes in DW, 13 of which are unprecedented. TPs were formed mainly via HO· preferential attack on the aromatic ring and on the α-carbon, and some of them were classified as persistent and toxic, genotoxic, or carcinogenic by Toxtree software. Results confirm that solar photocatalysis is less costly than to photocatalysis under black light for wastewater treatment.

Solar photo-Fenton treatment of the anti-cancer drug anastrozole in different aqueous matrices at near-neutral pH: Transformation products identification, pathways proposal, and in silico (Q)SAR risk assessment.

Anastrozole (ANZ) is a breast cancer drug that was introduced onto the pharmaceutical market in the 1990s and is still one of the most widely consumed cytotoxic compounds. Due to the persistence of the drug, its continued presence after passing through wastewater treatment plants can lead to harm to aquatic environments. The present study investigates use of the solar photo-Fenton (SPF) process applied for ANZ degradation, considering the fate of ANZ and its transformation products (TPs). The SPF process was performed using different concentrations of ferrous iron (Fe2+) and H2O2 in solutions produced with deionized water (DW) and hospital wastewater (HWW), at pH close to neutrality. When solar irradiation in the SPF process was carried out the best ANZ removal rates were found under the following conditions: (i) for the DW matrix, [ANZ]0 = 50 µg L-1, [Fe2+] = 5 mg L-1, and [H2O2]0 = 25 mg L-1, achieving 95% primary ANZ elimination; (ii) for the HWW matrix, [ANZ]0 = 50 µg L-1, [Fe2+] = 10 mg L-1(multiple additions), and [H2O2]0 = 25 mg L-1, achieving 51% primary ANZ elimination. LC-QTOF MS analysis allowed to identify tentatively five transformation products (TPs) formed during the ANZ degradation process in DW, and two TPs when HWW was used. The main proposed degradation pathways were demethylation and hydroxylation. Different in silico models free available (quantitative) structure-activity relationship ((Q)SAR) software were used to predict the ecotoxicities and environmental fates of ANZ and the TPs. The in silico (Q)SAR predictions indicated that ANZ and the TPs were non-biodegradable compounds. In silico (Q)SAR predictions for mutagenicity and carcinogenicity end-points identified some TPs that require further study. Attention is drawn to the formation of several TPs for which statistical and rule-based positive alerts for mutagenic activities were found, requiring further confirmatory in vitro validation tests.

Economically feasible strategy for confirmation of pharmaceuticals in hospital effluent using screening analysis.

The contamination of aquatic systems by pharmaceuticals has received considerable attention in recent decades, because these substances are increasingly detected in the environment. This is due to the abundant use of pharmaceuticals by the population and, consequently, their constant introduction into aquatic systems through domestic, industrial, and hospital wastewaters. Hospital effluents have highly complex compositions and present potential toxicity towards the environment. In this work, a screening methodology was developed to evaluate the occurrence of pharmaceutical products in hospital wastewater, using a viable, easy, and economical strategy employing commercial pharmaceutical compounds for screening analysis. Six samplings of hospital wastewater were carried out monthly (from winter until summer). The samples were filtered and pre-concentrated/extracted using solid phase extraction (SPE). The pharmaceuticals screening procedure required the construction of two databases, one for each ionization mode (positive and negative), which contained information that allowed the identification of the presence of these pharmaceuticals in the studied samples. Commercial pharmaceutical compounds were used as analytical standards. Based on this strategy and, using liquid chromatography coupled to high resolution mass spectrometry, it was possible to screen 110 pharmaceuticals and, from these, to confirm the presence of 38 pharmaceuticals in analyzed samples. These results indicate the analytes that should be taken into account in the further development of quantitative methods for pharmaceutical analysis.

Comparative endocrine disrupting compound removal from real wastewater by UV/Cl and UV/H2O2: Effect of pH, estrogenic activity, transformation products and toxicity.

Extensive use of endocrine disruptor compounds (EDCs) and their release through various pathways into the environment are emerging environmental concerns. In this context, H2O2 and chlorine UV-based treatments were carried out to evaluate their efficiency in the removal of the bisphenol A (BPA), 17ß-estradiol (E2) and 17α-ethinylestradiol (EE2) at 100 µg L-1 from ultrapure water and from wastewater treatment plants (WWTP). Photolysis was performed under different irradiation sources, i.e. UVC and UVA. The effect of H2O2 (3 and 30 mg·L-1), free chlorine concentrations (1 and 2 mg·L-1) and pH (5, 7 and 9) were also investigated. Toxicity (Raphidocelis subcapitata) and estrogenic activity (yeast estrogen screen - YES assay) were assessed during the processes. Compound removal at optimal operating parameters reached 100% after 15 and 2 min for UVC/H2O2 (pH 9 and 3 mg L-1 of H2O2), and UVC/Cl (pH 9 and 2 mg L-1 of chlorine), respectively. Total organic carbon (TOC) removal achieved 37% and 45% for the H2O2 and Cl-UV based process, respectively. The in vitro YES assay indicated that the formed by-products were non-estrogenic compounds, while the toxicity evaluation revealed high cell growth inhibition due to UVC/Cl byproducts. During the UV-based processes, 30 transformation products (TPs) were identified, in which three new chlorinated TPs from E2 and EE2 may be responsible for toxicity effects. EDC degradation by UV/Cl is faster than by UV/H2O2, although chlorinated toxic byproducts were also formed during the UV/Cl process.

Heterogeneous photocatalytic degradation of pharmaceuticals in synthetic and real matrices using a tube-in-tube membrane reactor with radial addition of H2O2.

A tube-in-tube membrane reactor, with radial addition of hydrogen peroxide, was used for the oxidation of four pharmaceuticals, paracetamol (PCT), furosemide (FRS), nimesulide (NMD), and diazepam (DZP), in a continuous-mode operation, using photochemical and photocatalytic processes, driven by UVA or UVC photons. This reactor allows a controlled titration of small H2O2 doses (inside-out mode) to the catalyst particles immobilized in the membrane shell side and to the annular space between the membrane inner tubing and the concentric outer quartz tubing, where water to be treated flows. Tests were performed using synthetic (SWW) and real (urban wastewater after secondary treatment) (UWW) matrices, both spiked with the pharmaceutical mix solution (200 µg L-1 of each). The photochemical and photocatalytic oxidation efficiency was evaluated as a function of H2O2 dose (5-20 mg L-1), oxidant injection mode (radial permeation vs injection upstream from the reactor inlet), light source (UVA vs UVC lamps) and aqueous matrix (synthetic vs real matrix). At steady-state regime, the UVC/H2O2/TiO2 system, with radial H2O2 addition (20 mg L-1), showed the highest pharmaceuticals removal percentage, PCT (27.4%), FRS (35.0%), NMD (24.2%) and DZP (30.0%) in SWW. A substantial decrease in pharmaceuticals elimination was observed for UWW (PCT - 11.5%, FRS - 20.3%, NMD - 8.2% and DZP - 12.6%), in comparison with the SWW matrix. Finally, twelve transformation products (TPs) were identified; most of them showed in their structures hydroxylation in aromatic moiety; all TPs chemical structures were evaluated by BIOWIN software indicating that the TPs are non-biodegradables.

Proposal of a new, fast, cheap, and easy method using DLLME for extraction and preconcentration of diazepam and its transformation products generated by a solar photo-Fenton process.

This work evaluated the formation of transformation products (TPs) during the degradation of diazepam (DZP) by a solar photo-Fenton process. Six TPs were identified, three of them for the first time. After elucidation of the TPs, a new, cheap, fast, and easy method was employed to extract and preconcentrate DZP and its TPs, using dispersive liquid-liquid microextraction (DLLME). The method was optimized using factorial and Doehlert designs, with the best results obtained using acetonitrile as disperser solvent and chloroform as extraction solvent, with volumes of 1000 and 650 µL, respectively. When DZP degradation was performed in ultrapure water, the extraction/preconcentration of DZP and its TPs by DLLME was very similar to the results obtained using a traditional SPE method. However, when hospital wastewater was used as the matrix, more limited extraction efficiency was obtained using DLLME, compared to SPE. Meanwhile, all the TPs extracted by SPE were also extracted by the DLLME technique. Furthermore, DLLME was much less expensive than SPE, besides being faster, easier, and requiring only small amounts of organic solvents. This work reports a new and very important tool for the extraction and preconcentration of TPs formed during degradation using techniques such as advanced oxidation processes (AOPs), since without this step it would not be possible to identify all the TPs formed in some complex wastewater matrices.

Combination of solar photo-Fenton and adsorption process for removal of the anticancer drug Flutamide and its transformation products from hospital wastewater.

The anti-cancer drug Flutamide (FLUT) is widely used and is of great environmental concern. The solar photo-Fenton (SPF) process can be an effective treatment for the removal of this type of micropollutant. The use of a single addition of 5 mg L-1 of Fe2+ and 50 mg L-1 of H2O2 achieved 20% primary degradation and only 3.05% mineralization. By using three additions of 5 mg L-1 Fe2+, with an initial H2O2 concentration of 150 mg L-1, 58% primary degradation was achieved, together with 12.07% mineralization. Consequently, thirteen transformation products (TPs) were formed. The SPF process was further combined with adsorption onto avocado seed activated carbon (ASAC) as an environmentally friendly approach for the removal of remained FLUT and the TPs. Doehlert design was used to assess the behavior of 13 TPs by optimizing the contact time and the adsorbent mass load. The optimal conditions for removal of FLUT and the TPs were 14 mg of ASAC and a contact time of 40 min. Remained FLUT and the TPs were totally removed using the adsorption process. The mechanisms of adsorption of FLUT and the TPs were strongly influenced by their polarity and π-π interactions of the TPs onto ASAC.

Degradation of the anticancer drug flutamide by solar photo-Fenton treatment at near-neutral pH: Identification of transformation products and in silico (Q)SAR risk assessment.

Flutamide (FLUT) is a non-steroidal drug mainly used in the treatment of prostate cancer and has been detected in the aquatic environment at ng L-1 levels. The environmental fate and effects of FLUT have not yet been studied. Conventional treatment technologies fail to completely remove pharmaceuticals, so the solar photo-Fenton process (SPF) has been proposed as an alternative. In this study, the degradation of FLUT, at two different initial concentrations in ultra-pure water, was carried out by SPF. The initial SPF conditions were pH0 5, [Fe2+]0 = 5 mg L-1, and [H2O2]0 = 50 mg L-1. Preliminary elimination rates of 53.4% and 73.4%. The kinetics of FLUT degradation could be fitted by a pseudo-first order model and the kobs were 6.57 × 10-3 and 9.13 × 10-3 min-1 t30W and the half-life times were 95.62 and 73.10 min t30W were achieved for [FLUT]0 of 5 mg L-1 and 500 µg L-1, respectively. Analysis using LC-QTOF MS identified thirteen transformation products (TPs) during the FLUT degradation process. The main degradation pathways proposed were hydroxylation, hydrogen abstraction, demethylation, NO2 elimination, cleavage, and aromatic ring opening. Different in silico (quantitative) structure-activity relationship ((Q)SAR) freeware models were used to predict the toxicities and environmental fates of FLUT and the TPs. The in silico predictions indicated that these substances were not biodegradable, while some TPs were classified near the threshold point to be considered as PBT compounds. The in silico (Q)SAR predictions gave positive alerts concerning the mutagenicity and carcinogenicity endpoints. Additionally, the (Q)SAR toolbox software provided structural alerts corresponding to the positive alerts obtained with the different mutagenicity and carcinogenicity models, supporting the positive alerts with more proactive information.

Investigation of pharmaceuticals and their metabolites in Brazilian hospital wastewater by LC-QTOF MS screening combined with a preliminary exposure and in silico risk assessment.

This work evaluates the occurrence of pharmaceuticals, with special emphasis on their metabolites, in raw hospital wastewater (HWW) using wide-scope screening based on liquid chromatography coupled to high resolution mass spectrometry. The applied strategy uses an extended purpose-built database, containing >1000 pharmaceuticals and 250 metabolites. Raw HWW samples from a hospital located in south Brazil were collected over six months, with a monthly sampling frequency. Accurate-mass full-spectrum data provided by quadrupole-time of flight MS allowed the identification of 43 pharmaceuticals and up to 31 metabolites in the samples under study. Additionally, other four metabolites not included in the initial database could be identified using a complementary strategy based on the common fragmentation pathway between the parent compound and its metabolites. Nine metabolites derived from four pharmaceuticals were identified in the raw HWW samples, whereas their parent compounds were not found in these samples. The results of this work illustrate the importance of including not only parent pharmaceuticals but also their main metabolites in screening analysis. Besides, the inclusion of in silico QSAR predictions allowed assessing the environmental fate and effect of pharmaceuticals and metabolites in terms of biodegradability, as possible Persistent, Bioaccumulative and Toxic (PBT) compounds, and their potential hazard to the aquatic environment.

Total dissolved iron and hydrogen peroxide determination using the PhotoMetrixPRO application: A portable colorimetric analysis tool for controlling important conditions in the solar photo-Fenton process.

The use of the solar photo-Fenton process for water treatment requires monitoring of the main conditions, especially the total dissolved iron concentration and the consumption of hydrogen peroxide. In this study, a new methodology using the PhotoMetrixPRO application was validated for rapid monitoring of total dissolved iron and hydrogen peroxide concentrations, and was tested in the solar photo-Fenton process. A comparison was made between the results obtained using a reference spectrophotometric method and the PhotoMetrixPRO application employing a portable device. Both methods were validated in terms of linearity, sensitivity, precision, robustness, and matrix effects. The degree of dispersion between the series of measurements obtained using UV-vis and portable device tool was low and was in compliance with the established Brazilian and ICH validation criteria. Additionally, PhotoMetrixPRO enabled the use of a smaller sample volume. The total volume generated of each sample is 1 mL, reducing 6 and 10 times the wastes produced in different validated methods. These results evidencing that the miniaturization can provide positive advantages in terms of simplicity, cost effectiveness, and less environmental impact. PhotoMetrixPRO offers significant advantages including rapid analysis, smaller sample volumes, and greater portability and accessibility.

Degradation of pharmaceuticals in different water matrices by a solar homo/heterogeneous photo-Fenton process over modified alginate spheres.

A solar homo/heterogeneous photo-Fenton process using five materials (Fe(II), Fe(III), mining waste, Fe(II)/mining waste, and Fe(III)/mining waste) supported on sodium alginate was used as a strategy to iron dosage for the degradation of eight pharmaceuticals in three different water matrices (distilled water, simulated wastewater, and hospital wastewater). Experiments were carried out in a photoreactor with a capacity of 1 L, using 3 g of iron-alginate spheres and an initial hydrogen peroxide concentration of 25 mg L-1, at pH 5.0. All the materials prepared were characterized by different techniques. The Fe(III)-alginate spheres presented the best pharmaceutical degradation after a treatment time of 116 min. Nineteen transformation products generated during the solar photo-Fenton process were identified by liquid chromatography coupled to quadrupole time-of-flight mass spectrometry, using a purpose-built database developed for detecting these transformation products. Finally, the transformation products identified were classified according to their toxicity and predicted biodegradability.