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BackgroundDiabetes mellitus (DM) is one of the leading chronic diseases globally and one of the most common causes of death, morbidity, and poor quality of life. According to the WHO, DM is also one of the main risk factors for developing active tuberculosis (TB). Subjects with DM are at a higher risk of infections, in addition to frequent micro and macrovascular complications, and therefore sought to determine whether poor glycemic control is linked to a higher risk of developing TB.MethodsWe used a retrospective cohort of diabetic subjects to predict the incidence of TB. All DM patients were recruited from Ciutat Vella (the inner-city of Barcelona) from January 2007 until December 2016, with a follow-up period until December 2018 (≥2 years). Data were extracted from Barcelona's Primary Care medical record database - SIDIAP, and linked to the Barcelona TB Control Program. The incidence of TB and the impact of glycemic control were estimated using time-to-event curves analyzed by Cox proportional hazard regression. Hazard ratios (HRs) and 95% confidence intervals (CIs), unadjusted and adjusted by potential confounding variables, were also assessed, which included age, sex, diabetes duration, macrovascular and microvascular signs, BMI, smoking habit, alcohol consumption and geographical origin.ResultsOf 8,004 DM patients considered for the study (equating to 68,605 person-years of follow-up), 84 developed TB [incidence rate = 70 (95% CI: 52–93) per 100,000 person-years]. DM subjects with TB were younger (mean: 52.2 vs. 57.7 years old), had higher values of glycosylated hemoglobin (HbA1c) (7.66 vs. 7.41%) and total triglycerides (122 vs. 105 mg/dl), and had twice the frequency of diabetic nephropathy (2.08 vs. 1.18%). The calculated incidence rate increased with increasing HbA1c: 120.5 (95% CI 77.2–179.3) for HbA1c ≥ 7.5%, 143 (95% CI 88.3–218.1) for HbA1c ≥ 8% and 183.8 (95% CI 105–298) for HbA1c ≥ 9%. An increase in the risk of TB was also observed according to a poorer optimization of glycemic control: adjusted HR 1.80 (95% CI 0.60–5.42), 2.06 (95% CI 0.67–6.32), and 2.82 (95% CI 0.88–9.06), respectively.ConclusionDiabetic subjects with worse glycemic control show a trend toward a higher risk of developing TB.

The assessment of environmental sustainability has assumed great importance during the study and implementation of a new process, including those aimed to waste valorization and reuse. In this research, the environmental performance of the photo-Fenton processes was evaluated using the life cycle assessment (LCA) methodology. In particular, photo-Fenton conducted in mild conditions (almost neutral pH), using soluble bio-organic substances as auxiliary agents were compared with the “classic” photo-Fenton run at pH 2.8. The evaluation was carried out both, at the laboratory level and at pilot plant scale. LCA analysis shows that working in mild conditions reduces the environmental burden associated with the use of chemicals. On the other hand, the occurring drop in effectiveness significantly increases the overall impact, thus evidencing the need of considering the process as a whole.

Commercial (fluoro)quinolones ((F)Qs), ciprofloxacin (CIP), enrofloxacin (ENR), ofloxacin (OFL), oxolinic acid (OA) and flumequine (FLU) (3 μM each), were degraded with solar-photo-Fenton in a compound parabolic concentrator photoreactor (total volume 5 L) in ultra-pure water at pH = 5.0, salty water at pH = 5.0, and simulated wastewater at pH = 5.0 and 7.5. Iron speciation (its hydrolysis and the complexation with (F)Qs 15 μM and/or chlorides 0.5 M) was calculated at pH 5.0, observing, negligible formation of Fe(III)-chloride complexes, and that99 % of the total (F)Qs are forming complexes stoichiometry 1:1 with Fe(III) (which also increases the percentage of Fe(OH)

[EN] Humiclike substances (HLS) have been demonstrated to be useful auxiliaries to drive the (photo)-Fenton process at mild pH, by avoiding iron inactivation via formation of active complexes. However, the actual performance of the process is affected by a manifold of opposite processes. In this work, the generation of hydroxyl radical-like reactive species in the Fentonlike process has been investigated using electron paramagnetic resonance, employing 5,5-dimethyl-1-pyrroline-N-oxide as a probe molecule. The signal obtained with the Fe(II)-HLS-H2O2 system at pH = was very intense but decreased with time, in line with the difficult reduction of the formed Fe(III) to Fe(II). On the contrary, the signal of the Fe(III)-HLS-H2O2 system was weak but stable. The most intense signal was observed at HLS concentration of ca. 30 mg/L. Interestingly, the performance of the Fenton system at pH = 5 to degrade caffeine followed the same trends, although caffeine removal was very low after 1 h of irradiation. The results were more evident in a solar simulated photo-Fenton process, where an increase in the abatement of caffeine was observed until an HLS concentration of 30 mg/L, where 98% removal was reached after 1 h., The authors want to acknowledge the financial support from Ministerio de Ciencia, Innovacion y Universidades (RTI2018-097997-B-C31) and European Union (645551-RISE-2014, MAT4TREAT). P.G.-N. would like to thank Spanish Ministerio de Economia y Competitividad for her fellowship (BES-2016-077962).

The degradation of various preservatives used in the cosmetics industry, including five parabens and their most employed substitute, methylisothiazolinone (MIT), was investigated. A mild photo-Fenton process was applied using low iron concentrations (5 mg/L) at a pH of five, instead of the traditional acidic value of three. At these conditions, the paraben degradation was very low after one hour of reaction and it was necessary to present humic-like substances (HLS) acting as iron chelators to improve the process. Values obtained when MIT was treated were very low, also in the presence of HLS, indicating that their complexing effect was not acting properly. When MIT was added to the mixture of parabens an inhibitory effect was found in the presence of HLS. A possible complex between iron and MIT was suggested and the studies of hydrogen peroxide consumption and Job’s plot technique confirmed this hypothesis. Evidence of the formation of this inactive complex, so far never reported, will be essential in future work when dealing with this compound using Fenton processes. Furthermore, this fact points out the importance of using mixtures of model contaminants instead of a single one or a group of the same family, since their ability to form active or inactive complexes with iron can strongly change the behavior of the whole system.

BackgroundTuberculosis is the leading cause of mortality from lung infectious disease worldwide in recent years, and its incidence has re-emerged in large cities in low-incidence countries due to migration and socioeconomic deprivation causes. Diabetes mellitus and tuberculosis are syndemic diseases, with diabetes being considered a risk factor for developing tuberculosis.ObjectiveTo investigate whether diabetic patients were at increased risk of tuberculosis living in an inner-district of a large city of northeastern Spain.MethodsObservational matched retrospective cohort study based on clinical records from the population of the lowest socioeconomic status in Barcelona (Ciutat Vella district). A cohort including patients with type 1 and type 2 diabetes mellitus in 2007 and new cases until 2016 (8004 subjects), matched 1:1 by sex and age with a non-diabetic cohort. Follow-up period was until December 31st 2018. We evaluated the risk of developing tuberculosis in diabetic patients compared to non-diabetic patients during the follow up period. We used time-to-event analysis to estimate the incidence of tuberculosis, and competing risks regression by clusters and conditional Cox regression models to calculate the hazard ratio (HR) and its 95% confidence intervals (CI).ResultsAmong the 16,008 included subjects, the median follow-up was 8.7 years. The mean age was 57.7 years; 61.2% men and 38.8% women in both groups. The incidence of tuberculosis was 69.9 per 100,000 person-years in diabetic patients, and 40.9 per 100,000 person-years in non-diabetic patients (HR = 1.90; CI: 1.18–3.07). After adjustment for the country of origin, chronic kidney disease, number of medical appointments, BMI, alcoholism and smoking, the risk remained higher in diabetic patients (1.66: CI 0.99–2.77). Additionally, subjects from Hindustan or with a history of alcohol abuse also showed a higher risk of developing tuberculosis (HR = 3.51; CI:1.87–6.57, and HR = 2.73; CI:1.22–6.12 respectively).ConclusionPeople with diabetes mellitus were at higher risk of developing tuberculosis in a large cohort recruited in an inner-city district with a high incidence for this outcome, and low socioeconomic conditions and high proportion of migrants. This risk was higher among Hindustan born and alcohol abusers.

[EN] Enrofloxacin (ENR) belongs to the fluoroquinolone (FQ) antibiotics family, which are contaminants of emerging concern frequently found in effluents. Although many works studying photo-Fenton process for FQ degradation have been reported, there are no reports analysing in deep the effect of iron complexation, as well as other metals, towards FQs' photolysis, which, evidently, also contributes in the overall degradation of the pollutant. Therefore, in this work, we report a comparative study between the photochemical fate of ENR and its complex with Fe(III) under simulated sunlight irradiation. In addition, the effect of dissolved oxygen, self-sensitization process, and H2O2 addition on the studied photochemical systems are also investigated. Results indicate that, for free and iron-complexed ENR, singlet oxygen (O-1(2)) is generated from the interaction of its triplet state with ground state oxygen. Half-life time (t(1/2)) of ENR under sun simulated conditions is estimated to be around 22 min, while complexation with iron enhances its photostability, leading to a t(1/2) of 2.1 h. Such finding indicates that at least the presence of iron, might notably increase the residence time of these pollutants in the environment. Eventually, only with the addition of H2O2, the FQ-iron complex is efficiently degraded due to photo-Fenton process even at circumneutral pH values due to the high stability of the formed complex. Finally, after LC/FT-ICR MS analysis, 39 photoproducts are detected, of which the 14 most abundant ones are identified. Results indicate that photoproducts formation is pH and iron dependent., This paper is part of a project that has received funding from the European Union's Horizon 2020 research and innovation programme under the Marie Sklodowska-Curie grant agreement No. 765860 (AQUAlity). The paper reflects only the authors' view and the Agency is not responsible for any use that may be made of the information it contains. M.B. and G. M. acknowledge financial support from the CAP 20-25 I-site project.

Tuberculosis (TB) is the leading cause of infectious mortality in the world, affecting mainly developing countries (DC), while diabetes (DM) is one of the most prevalent chronic diseases. This review analyzes the fact that diabetes is currently an important risk factor for developing TB, also presenting more complicated TB, more relapses and higher mortality. The DCs and the fourth world of the large cities are those with the highest incidence of TB and an increase in DM, which will make it difficult to control tuberculosis disease. At the same time, the COVID-19 pandemic is complicating the management of both diseases due to the difficulty of access to control and treatment and the worsening of socioeconomic inequalities. It is necessary to establish a bidirectional screening for TB and DM and promote recommendations for the joint management of both diseases.La tuberculosis (TB) era la primera causa de mortalidad infecciosa mundial hasta la pandemia de COVID-19. Afecta sobre todo a los países en vías de desarrollo (PVD), mientras que la diabetes mellitus (DM) es una de las enfermedades crónicas más prevalentes.En esta revisión se objetiva que la DM constituye actualmente un importante factor de riesgo para desarrollar TB, presentando además TB más complicadas, más recaídas y mayor letalidad. Los PVD y el cuarto mundo de las grandes ciudades son los que presentan mayor incidencia de TB y un incremento de la DM, lo que dificultará el control de la enfermedad tuberculosa. Paralelamente, la pandemia por COVID-19 está complicando el manejo de ambas enfermedades por la dificultad de acceso al control y tratamiento y por el empeoramiento de desigualdades socioeconómicas. Es necesario establecer un cribado bidireccional de TB y DM e impulsar recomendaciones para el manejo conjunto de ambas enfermedades.

[EN] In the present work, the treatment of a mixture of six emerging pollutants (acetamiprid, acetaminophen, caffeine, amoxicillin, clofibric acid and carbamazepine) by means of photo-Fenton process has been studied, using simulated sunlight as an irradiation source. Removal of these pollutants has been investigated in three different aqueous matrices distinguished by the amount of chlorides (distilled water, 1 g L-1 of NaCl and 30 g L-1 of NaCl) at a pH of 2.8 and 5.0. Interestingly, the presence of 1 g L-1 was able to slightly accelerate the pollutants removal at pH = 5, although the reverse was true at pH = 2.8. This is attributed to the pH-dependent interference of chlorides on photo-Fenton process, that is more acute in an acidic medium. As a matter of fact, the fastest reaction was obtained at pH = 3.5, in agreement with literature results. Monitoring of hydrogen peroxide consumption and iron in solution indicates that interference with chlorides is due to changes in the interaction between iron and the peroxide, rather than a scavenging effect of chloride for hydroxyl radicals. Experiments were also carried out with real seawater and showed higher inhibition than in the NaCl experiments, probably due to the effect of different dissolved salts present in natural water., This research was funded by Spanish Ministry of Science, Innovation and Universities, AEI and FEDER for funding under the CalypSol Project (Ref: RTI2018-097997-B-C31) and the cofunding by the 2014-2020 ERDF Operational Programme and by the Department of Economy, Knowledge, Business and University of the Regional Government of Andalusia (Spain). Ref.: FEDER-UCA18-108023. J. Moreno-Andres is grateful to Generalitat Valenciana (Spain) (APOSTD/2019/207) and the financial support from the European Social Fund (ESF).

[EN] The development of treatment trains for pollutant degradation employing zerovalent iron has been attracting a lot of interest in the last few years. This approach consists of pre-treatment only with zerovalent iron, followed by a Fenton oxidation taking advantage of the iron ions released in the first step. In this work, the advantages/disadvantages of this strategy were studied employing commercial zerovalent iron microparticles (mZVI). The effect of the initial amount of mZVI, H2O2, pH, conductivity, anions and dissolved oxygen were analysed using p-nitrobenzoic acid (PNBA) as model pollutant. 83% reduction of PNBA 6 mu M into p-aminobenzoic acid (PABA) was achieved in natural water at an initial pH 3.0 and 1.4 g/L of mZVI, under aerobic conditions, in 2 h. An evaluation of the convenience of removing mZVI after the reductive phase before the Fenton oxidation was investigated together with mZVI reusability. The Fenton step against the more reactive PABA required 50 mg/L of H2O2 to achieve more than 96% removal in 15 min at pH 7.5 (final pH from the reductive step). At least one complete reuse cycle (reduction/oxidation) was achieved with the separated mZVI. This approach might be interesting to treat wastewater containing pollutants initially resistant to hydroxyl radicals., This work is part of a project that has received funding from the European Union's Horizon 2020 research and innovation programme under the Marie Sklodowska-Curie grant agreement No. 765860 (AQUAlity). The paper reflects only the authors view and the Agency is not responsible for any use that may be made of the information it contains.

In this work, we have tested a photocatalytic material consisting of a core of SiO2/Fe3O4 coated with TiO2 (Magnox) for plausible tertiary wastewater treatment. For this, a pilot plant of 45 L equipped with an Ultraviolet light (UVC) lamp was employed to study the degradation of a model contaminant, enrofloxacin (ENR), as well as water disinfection (elimination of Escherichia coli and Clostridium perfringens). The influence of different operational conditions was explored by means of dye (rhodamine-B) decolorization rates, analyzing the effects of photocatalyst quantity, pH and recirculation flow rates. The magnox/UVC process was also compared with other four Advanced Oxidation Processes (AOPs): (i) UVC irradiation alone, (ii) hydrogen peroxide with UVC (H2O2/UVC), (iii) Fenton, and (iv) photo-Fenton. Although UVC irradiation was efficient enough to produce total water disinfection, only when employing the AOPs, significant degradations of ENR were observed, with photo-Fenton being the most efficient process (total enrofloxacin removal in 5 min and c.a. 80% mineralization in 120 min, at pH0 2.8). However, Magnox/UVC has shown great pollutant abatement effectiveness under neutral conditions, with the additional advantage of no acid or H2O2 addition, as well as its plausible reuse and simple separation due to its magnetic properties.

In this work, fluorescence excitation–emission matrices (EEMs), in combination with the chemometric tool and parallel factor analysis (PARAFAC), have been proposed as an unexplored methodology to follow the removal of the fluorescent contaminants of emerging concern, fluoroquinolones (FQs). Ofloxacin, enrofloxacin, and sarafloxacin were degraded by different advanced oxidation processes employing simulated sunlight (hν): photolysis, H2O2/hν, and photo-Fenton. All experiments were performed in ultrapure water at three different pH values: 2.8, 5.0, and 7.0. With the obvious advantage of multivariate analysis methods, EEM-PARAFAC allowed the monitoring of degradation from the overall substances (original and formed ones) through simultaneous, rapid, and cost-efficient fluorescence spectroscopy determinations. A five-component model was found to best fit the experimental data, allowing us to (i) describe the decay of the fluorescence signals of the three parent pollutants, (ii) follow the kinetics profile of FQ-like byproducts with similar EEM fingerprints than the original FQs, and (iii) observe the formation of two families of reaction intermediates with completely different EEMs. Results were finally correlated with high pressure liquid chromatography, total organic carbon, and toxicity tests on Escherichia coli, showing good agreement with all the studied techniques.

[EN] The degradation of enrofloxacin (ENR) by direct photolysis, Fenton and solar photo-Fenton processes has been studied in different water matrices, such as ultra-pure water (MQ), tap water (TW) and highly saline water (SW). Reactions have been conducted at initial pH 2.8 and 5.0. At pH = 2.8, HPLC analyses showed a fast removal of ENR by (solar photo)-Fenton treatments in all studied water matrices, whereas a 40% removal was observed after 120 min of photolysis. However, TOC measurements showed that only solar photo-Fenton was able to produce significant mineralization (80% after 120 min of treatment); differences between ENR removal and mineralization can be attributed to the release of important amounts of reaction by-products. Excitation-emission matrices (EEMs) combined with parallel factor analysis (PARAFAC) were employed to gain further insight into the nature of these by-products and their time-course profile, obtaining a 5-component model. EEM-PARAFAC results indicated that photolysis is not able to produce important changes in the fluoroquinolone structure, in sharp contrast with (solar photo)-Fenton, where decrease of the components associated with fluoroquinolone core was observed. Agar diffusion tests employing E. toll and S. aureus showed that the antibiotic activity decreased in parallel with the destruction of the fluoroquinolone core., This paper is part of a project that has received funding from the European Union's Horizon 2020 - Research and Innovation Framework Programme under the H2020 Marie Sklodowska-Curie Actions grant agreement No 765860. The paper reflects only the authors' view and the Agency is not responsible for any use that may be made of the information it contains.

Olive mill waste has been used as sourcing materials for the isolation of humic like substances (OMW-HLS) which have demonstrated its capacity to expand the range of applicability of photo-Fenton process to pH=5. During the isolation process, membranes of three different pore sizes (300 kDa, 150 kDa and 50 kDa) were employed in order to obtain three batches of OMW-HLS. Four pollutants contained in 2013/39/EC were used as target substances: terbutryn (TBT), diclofenac (DCF), chlorfenvinphos (CVF) and pentachlorophenol (PCP). Results showed that OMW-HLS was able to enhance photo-Fenton at pH = 5, but differences were not significant, either among fractions or with commercial humic substances. Reactions were scaled-up and driven under real sunlight and pollutants removal was faster in the presence of OMW-HLS. Toxicity was monitored according to bioassays based on different organisms or cell lines. Detoxification was observed with and without OMW-HLS, although higher toxicity was detected in the presence of humic acids, most probably due to the surfactant effect, that allows a better contact between pollutant and organism.

In the present work, the photo-Fenton degradation of pentachlorophenol (PCP, 1 mg/L) has been studied under simulated and natural solar irradiation, moreover, the effect on the process efficiency of urban waste-derived soluble bio-based substances (SBO), structurally comparable to humic acids, has been investigated. Experiments showed a crucial role of PCP photolysis, present in the solar pilot plant and hindered by the Pyrex&reg, filter present in the solar simulator. Indeed, the SBO screen negatively affects PCP degradation when working under natural solar light, where the photolysis of PCP is relevant. In contrast, in the absence of PCP photolysis, a significant improvement of the photo-Fenton process was observed when added to SBO. Furthermore, SBO were able to extend the application of the photo-Fenton process at circumneutral pH values, due to their ability to complex iron, avoiding its precipitation as oxides or hydroxides. This positive effect has been observed at higher concentration of Fe(II) (4 mg/L), whereas at 1 mg/L, the degradation rates of PCP were comparable in the presence and absence of SBO.

[EN] Fluorescence has been widely employed for the characterization of organic matter. In particular, excitation emission matrixes (EEM) provide important qualitative information on its composition. However, the application of this technique is limited by the mathematical complexity involved, which requires the use of PARAFAC for deconvolution of the EEM in their components. To overcome the numerical problem specific MATLAB toolboxes for the PARAFAC deconvolution have been implemented (e.g. drEEM). This toolbox is widely used by the scientific community but its intrinsic complexity in terms of programming knowledge makes it difficult to use. In this regard and in order to facilitate the first approximation to the PARAFAC programming problem, this paper describes and offers to the community the EEMlab software application: a graphical user-firendly interface for fluorimetry experiments based on the drEEM toolbox. The interface is developed in order to facilitate not only the intuitive use of the drEEM (no previous MATLAB knowledge is needed) but also to automate many repetitive tasks (as the data load or the modeling loop) or even to manage the different formats of files being produced by all the devices involved in the process. In order to validate the EEMlab, the same experiment documented by the drEEM is reproduced. In addition, the EEMlab is tested again with conducting a new fluorimetry experiment and the results are presented at the end of the paper. Finally to appoint a reference to the public web site pabmitor.webs.upv.es/eemlab in where all the components of the EEMlab GUI (software, tutorial and datasets) are publicly available to the readers., The authors want to thank the financial support of the Generalitat Valenciana, Conselleria d'Educacio, Cultura i Esport (Spain) [GV/2015/074]. The authors want to thank the financial support of Ministerio de Educacion y Ciencia (Spain)(CTQ2015-69832-C4-4-R). Sara Garcia-Ballesteros would like to thank Ministerio de Economia y Competitividad (Spain) for her fellowship (BES-2013-066201). The authors want to thank Dr. F.S. García Einschlag who has independently tested the EEMlab and helped the authors to improve and validate the final version of the application.

The valorization of low-cost biobased resources (such as biomasses and their derivatives) as alternative feedstock for the preparation of innovative sustainable materials allows both economic and environmental benefits, for instance when these materials enhance the photodegradation of organic pollutants in water remediation processes. This chapter presents the physicochemical features of biobased substances (BBS) isolated from urban organic residues, and it reports on their performances as chemical auxiliaries in advanced oxidation processes (AOPs). In the homogeneous phase, BBS can indeed promote the direct oxidation of organic pollutants through the formation of many reactive species, and it can also allow running Fenton and photo-Fenton processes at circumneutral pH. Additionally, BBS can be used in heterogeneous phase. In addition, the preparation, characterization, and pollutant photodegradation efficiency of novel heterogeneous systems based on hybrid magnet-responsive materials functionalized with biobased substances is discussed, whereas the functionalization with oxidative enzymes is presented as well.

[EN] Soybean peroxidase (SBP) has been employed for the treatment of aqueous solutions containing pentachlorophenol (PCP) in the presence of hydrogen peroxide at pH range 5-7. Reaction carried out with 1mg/L of PCP, 4mg/L of H2O2, and 1.3x10(-9)M of SBP showed a fast initial elimination of PCP (ca. 30% in 20min), but the reaction does not go beyond the removal of 50% of the initial concentration of PCP. Modification in SBP and PCP amounts did not change the reaction profile and higher amounts of H2O2 were detrimental for the reaction. Addition of Fe(II) to the system resulted in an acceleration of the process to reach nearly complete PCP removal at pH 5 or 6; this is more probably due to a synergetic effect of the enzymatic process and Fenton reaction. However, experiments developed in tap water resulted in a lower PCP elimination, but this inconvenience can be partly overcome by leaving the tap water overnight in an open vessel before reaction., We want to acknowledge Davide Mainero from Acea Pinerolese for his collaboration in this research. The authors want to thank the financial support of the European Union (PIRSES-GA-2010-269128, EnvironBOS and Marie Sklodowska-Curie Research and Innovation Staff Exchange projectH2020-MSCA-RISE-2014, Mat4treaT-project number: 645551) and Spanish Ministerio de Educacion y Ciencia (CTQ2015-69832-C4-4-R). Sara Garcia-Ballesteros would like to thank the Spanish Ministerio de Economia y Competitividad for her fellowship (BES-2013-066201).

[EN] Urban-waste bio-organic substances (UW-BOS) have been shown to be capable of extending the photo-Fenton reaction to mildly acidic conditions. In this study, the effects of pH (3-7), UW-BOS, H2O2 and iron concentrations on the photo-Fenton process were systematically assessed using a Doehlert experimental design and response surface methodology for two UW-BOS (CVT230 and FORSUD). Solutions of the model antibiotic sulfadiazine (SDZ) were irradiated in a solar simulator equipped with a 550W Xenon lamp. The results showed that for UW-BOS contents below 30mg L-1, SDZ removal proceeds at pH 5 with similar rates for both CVT230 and FORSUD, regardless of Fe(III) concentration. For 50mg L-1 of UW-BOS or higher, CVT230 performs better than FORSUD, even for low Fe(III) content (1-3mg L-1). In contrast, half-life times of 35-40min can only be achieved under mildly acidic conditions with FORSUD for iron concentrations higher than 10mg L-1. The better performance of CVT230 can be associated with its high hydrophilic/hydrophobic ratio, low E2:E3, higher iron content and possibly higher yields of triplet reactive species generation upon solar irradiation. The most appropriate conditions for each UW-BOS studied are discussed for the first time, which are advantageous for possible engineered applications., The authors express their gratitude to CNPq (National Council for Scientific and Technological Development) and to the European Union (PIRSES-GA-2010-269128, EnvironBOS). This study was financed in part by the Coordenacao de Aperfeicoamento de Pessoal de Nivel Superior - Brasil (CAPES) - Finance Code 001.

[EN] The photodegradation of an aqueous solution of diclofenac (DCF) has been attempted in the presence of hydrogen peroxide and organic/inorganic hybrid magnetic materials under simulated and real solar light. The hybrid magnetic materials have been prepared via coprecipitation synthesis starting from iron(II) and iron(III) inorganic salts in the presence of bioderived organic products (i.e., chitosan or bio-based substances isolated from commercially available composted urban biowastes) acting as stabilizers of the iron-containing phase. In addition to the as prepared hybrid materials, the corresponding materials obtained after a pyrolytic step at low temperature (550 degrees C) have been tested. The obtained results evidenced the capability of the materials to activate hydrogen peroxide at mild pH promoting DCF (photo) degradation. All the materials feature also as adsorbents since a decrease of DCF is observed also when working in the dark and in the absence of hydrogen peroxide., This work was realized with financial support for academic interchange from the Marie Sklodowska-Curie Research and Innovation Staff Exchange project, funded by the European Commission H2020-MSCA-RISE-2014 within the framework of the research project Mat4treaT (Project number: 645,551). Politecnico di Torino is gratefully acknowledged for funding project Starting Grant RTD (project number: 54_RSG17NIR01).

[EN] Photo-induced Advanced Oxidation Processes (AOPs) using H2O2 or S2O82- as radical precursors were assessed for the abatement of six different contaminants of emerging concern (CECs). In order to increase the efficiency of these AOPs at a wider pH range, the catechol organic functional compound was studied as a potential assistant in photo-driven iron-based processes. Different salinity regimes were also studied (in terms of Cl- concentration), namely low salt water (1 g center dot L-1) or a salt-water (30 g center dot L-1) matrix. Results obtained revealed that the presence of catechol could efficiently assist the photo-Fenton system and partly promote the photo-induced S2O82- system, which was highly dependent on salinity. Regarding the behavior of individual CECs, the photo-Fenton reaction was able to enhance the degradation of all six CECs, meanwhile the S2O82--based process showed a moderate enhancement for acetaminophen, amoxicillin or clofibric acid. Finally, a response-surface methodology was employed to determine the effect of pH and catechol concentration on the different photo-driven processes. Catechol was removed during the degradation process. According to the results obtained, the presence of catechol in organic macromolecules can bring some advantages in water treatment for either freshwater (wastewater) or seawater (maritime or aquaculture industry)., This research was funded by Spanish Ministry of Science, Innovation and Universities, AEI and FEDER for funding under the CalypSol Project (Ref: RTI2018-097997-B-C31) and the co-funding by the 2014-2020 ERDF Operational Programme and by the Department of Economy, Knowledge, Business and University of the Regional Government of Andalusia (Spain). Ref.: FEDER-UCA18-108023. J. Moreno-Andres is grateful to Generalitat Valenciana (Spain) (APOSTD/2019/207) and the financial support from the European Social Fund (ESF).

[EN] The chemical decolorization of the azo-dye Acid Black 1 (AB1) by ZVI-assisted Fenton systems was investigated for assessing the relative importance of reductive and oxidative pathways. To this end, system evolution was followed by UV-vis, HPLC, CG-MS, TOC and toxicity measurements. The effects of reaction conditions including initial pH, oxidants (O-2 and H2O2) concentrations, ZVI loading, and the presence of SO42- were studied. Mechanistic issues were addressed by following H2O2, Fe(II), Fe(III) and pH profiles, as well as by performing experiments in the presence of iron-complexing agents (o-phenanthroline and EDTA) or reactive species scavengers (2-propanol and DMSO). Results show that AB1 reduction occurs through heterogeneous processes with moderate to low pH dependent rates, whereas AB1 oxidation is ruled by the Fenton reaction with significantly pH dependent rates. Mechanistic studies demonstrated that AB1 decolorization in ZVI-assisted Fenton systems involves both oxidative and reductive pathways, whose relative contributions significantly change as the initial pH is raised from 3 to 5. In acidic media, AB1 is mostly transformed by oxidative pathways linked to H2O2 consumption. In contrast, in circumneutral media, a rather inefficient H2O2 consumption leads to similar contributions of oxidative and reductive AB1 transformation pathways. A detailed analysis of the pH dependence of the key reactions involved suggests that the overall system behavior is ruled by a shift in the oxidation mechanism of Fe(II) species, as a consequence of the development of a thigh corrosion layer onto ZVI particles at circumneutral pH values., The present work was partially supported by UNLP (11/X679), ANPCyT (PICT-2012-0423, PICT-2015-0374) and CONICET (PIP: 12-2013-01-00236CO). Authors also want to acknowledge the economic support of European Union Call: (H2020-MSCA-RISE-2014, Proyect 645551 (MAT4TREAT). A. Argues and L. Carlos want to acknowledge Spanish Ministerio de Economia y Competividad (CTQ2015-69832, Triceratops Project). A. Donadelli thank the CONICET for his research graduate grant. L. Carlos and F. S. Garcia Einschlag are research members of CONICET.

Flusilazole is an organosilane fungicide used for treatments in agriculture and horticulture for control of diseases. The reaction kinetics and mechanism of flusilazole with sulfate and hydroxyl radicals were studied. The rate constant of the radicals with the fungicide were determined by laser flash photolysis of peroxodisulfate and hydrogen peroxide. The results were 2.0 × 109 s-1M-1 for the reaction of the fungicide with HO· and 4.6 × 108 s-1 M-1 for the same reaction with SO4·⁻ radicals. The absorption spectra of organic intermediates detected by laser flash photolysis of S2O2/8⁻ with flusilazole, were identified as α-aminoalkyl and siloxyl radicals and agree very well with those estimated employing the time-dependent density functional theory with explicit account for bulk solvent effects. In the continuous photolysis experiments, performed by photo-Fenton reaction of the fungicide, the main degradation products were: (bis(4-fluorophenyl)-hydroxy-methylsilane) and the non-toxic silicic acid, diethyl bis(trimethylsilyl) ester, in ten and twenty minutes of reaction, respectively., Facultad de Ciencias Exactas, Instituto de Investigaciones Fisicoquímicas Teóricas y Aplicadas

[EN] The valorization of olive oil mill solid wastes (OMW) has been addressed by considering it as a possible source of humic-like substances (HLSs), to be used as auxiliary substances for photo-Fenton, employing caffeine as a target pollutant to test the efficiency of this approach. The OMW-HLS isolation encompassed the OMW basic hydrolysis, followed by ultrafiltration and drying. OMW-HLS structural features have been investigated by means of laser light scattering, fluorescence, size exclusion chromatography, and thermogravimetric analysis; moreover, the capability of OMW-HLS to generate reactive species under irradiation has been investigated using spin-trap electronic paramagnetic resonance. The caffeine degradation by means of photo-Fenton process driven at pH = 5 was significantly increased by the addition of 10 mg/L of OMW-HLS. Under the mechanistic point of view, it could be hypothesized that singlet oxygen is not playing a relevant role, whereas other oxidants (mainly OH center dot radicals) can be considered as the key species in promoting caffeine degradation., Authors want to acknowledge the financial support of Spanish Ministerio de Economia y Competitividad (CTQ2015-69832-C04) and European Union (645551-RISE-2014, MAT4-TREAT).

[EN] Humic-like substances (HLS) extracted from urban wastes have been tested as auxiliaries for the photo Fenton removal of thiabendazole (TBZ) under simulated sunlight. Experimental design methodology based on Doehlert matrices was employed to check the effects of hydrogen peroxide concentration, HLS amount as well as TBZ loading; this last parameter was studied in the range 25-100 mg/L, to include values below and above the limit of solubility at pH = 5. Very satisfactory results were reached when TBZ was above solubility if HLS and H2O2 amounts were high. This could be attributed to an interaction of HLS-TBZ that enhances the solubility of the pollutant. Additional evidence supporting the latter interaction was obtained by fluorescence measurements (excitation emission matrices) and parallel factor analysis (PARAFAC). (C) 2018 Elsevier Ltd. All rights reserved., Authors want to acknowledge the financial support of Spanish Ministerio de Economia y Competitividad (CTQ2015-69832-C04) and European Union (645551-RISE-2014, MAT4TREAT). The present work was partially supported by UNLP (11/X679), ANPCyT (PICT-2015-0374A) and CONICET (PIP: 12-2013-01-00236CO). B. Caram thank the CONICET for his research graduate grant. F. S. Garcia Einschlag is a research member of CONICET.

[EN] Advanced oxidation processes are useful methodologies to accomplish abatement of contaminants; however, elucidation of the reaction mechanisms is hampered by the difficult detection of the short-lived primary key species involved in the photocatalytic processes. Nevertheless, herein the combined use of an organic photocatalyst such as triphenylpyrylium (TPP+) and photophysical techniques based on emission and absorption spectroscopy allowed monitoring the photocatalyst-derived short-lived intermediates. This methodology has been applied to the photocatalyzed degradation of different pollutants, such as acetaminophen, acetamiprid, caffeine and carbamazepine. First, photocatalytic degradation of a mixture of the pollutants showed that acetaminophen was the most easily photodegraded, followed by carbamazepine and caffeine, being the abatement of acetamiprid almost negligible. This process was accompanied by mineralization, as demonstrated by trapping of carbon dioxide using barium hydroxide. Then, emission spectroscopy measurements (steady-state and time-resolved fluorescence) allowed demonstrating quenching of the singlet excited state of TPP+. Laser flash photolysis experiments with absorption detection showed that oxidation of contaminants is accompanied by TPP+ reduction, with formation of a pyranyl radical (TPP center dot), that constituted a fingerprint of the redox nature of the occurring process. The relative amounts of TPP center dot detected was also correlated with the efficiency of the photodegradation process., Financial support from Spanish Government (Grants SEV-2016-0683, CTQ2012-38754-C03-02 and CTQ2015-69832-C4-4-R) and Generalitat Valenciana (Prometeo Program) is gratefully acknowledged. R. Martinez-Haya thanks financial support from Spanish Government (Grant SEV-2012-0267).

[EN] A kinetic-based rationale to assess the role of each excited species in thermodynamically favoured photocatalytic processes at different pollutant concentrations, has been developed and illustrated with new experimental data. Specifically, 2,4,6-triphenylthiapyrylium (TPTP+) salt has been chosen as a representative organic compound capable to act as photocatalyst, and the possible involvement of its excited states in the photodegradation of pollutants commonly found in aqueous ecosystems has been investigated using five chemicals, namely acetaminophen, acetamiprid, caffeine, clofibric acid and carbamazepine. First, steady-state photolysis has been carried out under simulated solar irradiation in the presence of TPTP+, and second, photophysical measurements (fluorescence and laser flash photolysis) have been performed in order to obtain reliable fast kinetic data. Thermodynamic considerations allow ruling out energy transfer processes, while the kinetic results are in good agreement with an electron transfer to the triplet excited state of TPTP+. Hence, the higher the intersystem crossing quantum yield the better. Although quenching of the singlet excited state is also observed, the contribution of this reactive species is only minor, due to its shorter lifetime. In general, the efficiency of a photocatalyst should be enhanced at higher pollutant concentrations, at which the intrinsic decay of the triplet excited state is minimized. (C) 2016 Elsevier B.V. All rights reserved., Financial support from Spanish Government (Grants SEV-2012-0267, CTQ2012-38754-C03-03 and CTQ2015-69832-C4-4-R) and Generalitat Valenciana (Prometeo Program) is gratefully acknowledged. R. Martinez-Haya thanks financial support from Spanish Government (Grant SEV-2012-0267). We also thank support from VLC/Campus.

[EN] The aim of this paper is to provide an overview on the different approaches that can be employed to drive a photo-Fenton process under mild conditions, using both heterogeneous and homogeneous iron sources. For this purpose, sections are devoted to the following strategies: a) addition of iron at low concentrations; b) using the matrix of the effluent in order to avoid deactivation of iron; c) addition of chemical auxiliaries to form photoactive complexes with iron, such as carboxylates, chelating agents and humic-like macromolecules; d) strategies leading to the application of heterogeneous photo-Fenton process, by using iron-based solid particles or by hosting iron on different supports and; e) using heterogeneous iron sources as a reservoir for constant dosing of homogeneous iron photocatalyst. In particular, the review will focus on the elimination of emerging pollutants (e.g. drugs, personal care products or pesticides at low concentrations) which are the effluents where applying neutral photo-Fenton seems especially meaningful, although relevant works with other families of pollutants are also considered, This work was performed with the financial of the Marie Sklodowska-Curie Research and Innovation Staff Exchange project funded by the European Commission H2020-MSCA-RISE-2014, within the framework of the research project Mat4treat. Authors also want to thank the financial support of Spanish Ministerio of Economía y Competitividad (TRICERATOPS project and FOTO-CAT excellence network).

[EN] In this work, analysis of excitation-emission-matrices (EEM) has been employed to gain further insight into the characterization of humic like substances (HLS) obtained from urban wastes (soluble bio-organic substances, SBOs). In particular, complexation of these substances with iron and changes along a photo-Fenton process have been studied. Recorded EEMs were decomposed by using parallel factor analysis (PARAFAC). Three fluorescent components were identified by PARAFAC modeling of the entire set of SBO solutions studied. The EEM peak locations (lambda(ex)/lambda(em)) of these components were 310-330 nm/400-420 nm (C1), 340-360 nm/450-500 nm (C2), and 285 nm/335-380 nm (C3). Slight variations of the maximum position of each component with the solution pH were observed. The interaction of SBO with Fe(III) was characterized by determining the stability constants of the components with Fe(III) at different pH values, which were in the order of magnitude of the ones reported for humic substances and reached their highest values at pH = 5. Photochemical experiments employing SBO and Fe(III), with and without H2O2, showed pH-dependent trends for the evolution of the modeled components, which exhibited a strong correlation with the efficiency reported for the photo-Fenton processes in the presence of SBO at different pH values., This work was supported by Generalitat Valenciana, Conselleria d'Ecuacio, Cultura i esport, Spain (GV/2015/074), Spanish Ministerio de Economia y Competitividad (CTQ2015-69832-C4-4-R) and by the Marie Sklodowska-Curie Research and Innovation Staff Exchange project funded by the European Commission H2020-MSCA-RISE-2014 (Project number: 645551). F. S. G. E. and L. C. are researchers from CONICET, Argentina.

BACKGROUND The presence of pesticides in surface and ground waters can trigger serious environmental problems, particularly in those areas where agriculture is the major economic activity. In this respect, photochemical advanced oxidation processes may be employed to decontaminate such matrices. RESULTS Semiconductor photocatalysis was employed to treat a mixture of four commercial pesticides (oxydemethon-methyl, methidathion, carbaryl and dimethoate at 25 mg L−1 each). Laboratory scale experiments under UV-A irradiation were performed to evaluate the relative activity of six commercially available titania samples at 0.5 g L−1 concentration, with Evonik P25 (a 75:25 mixture of anatase:rutile) being the most effective one in terms of pesticides degradation. Experiments were then performed in a pilot plant reactor under natural sunlight leading to quantitative removal of pesticides in less than 300 min; this was accompanied by a substantial reduction of acute toxicity to Vibrio fischeri (i.e. from an initial value of 50% to 15%), as well as moderate mineralization, i.e. 40% COD and 25% DOC removal. CONCLUSIONS The use of sunlight, a renewable energy source, alongside a commercially available, inexpensive and active titania photocatalyst may offer a sustainable treatment option to detoxify this type of wastewater. © 2014 Society of Chemical Industry

The effect of soluble bio-based organic substances (SBO) isolated from urban wastes on photochemical wastewater treatments was investigated using a mixture of six emerging pollutants (EPs), namely acetaminophen, caffeine, acetamiprid, clofibric acid, carbamazepine and amoxicillin. Solar simulated experiments showed that although SBO were able to enhance the indirect photolysis of the EPs, they could not compensate for the light screening effect produced by these colored materials. In contrast, SBO were able to enhance photo-Fenton at slightly acidic conditions (pH = 5.2), most probably increasing iron availability. In the later case, the order of reactivity (amoxicillinPcarbamazepine Pclofibric acid > caffeine > acetaminophen > acetamiprid) was similar to that of the rate constants determined for all six EPs with OH. Finally, experiments performed at pilot plant scale with real sunlight at pH = 5.2 and SBO showed that 5 of the EPs were removed in only 25 min and only acetamiprid was more resistant to the process. The overall results show not only how we can use waste to clean out wastes, but also contribute to the studies which show how wastes can become a source of revenue through the industrial exploitation of their chemical value., The authors want to thank the financial support of the European Union (PIRSES-GA-2010-269128, EnvironBOS) and Spanish Ministerio de Economia y Competitividad (CTQ2012-38754-C03-02). L. Carlos wishes to acknowledge CONICET (Argentina) and D.O. Martire to CIC (Provincia de Buenos Aires, Argentina). Part of this work was carried also with the Italian Ministero delle Politiche Agricole funds within the Agrienergia project. The authors are grateful to the following private and/or public Italian institutions: (a) Acea Pinerolese Spa in Pinerolo (TO) for supplying the SBO sourcing biowastes; (b) Studio Chiono ed Associati in Rivarolo Canavese (TO) for making available pilot equipment and services for the production of SBO.

Emerging pollutants, such as drugs, are considered a potential hazard to the environment, and therefore advanced oxidation processes are being considered candidate tools for their elimination. Here, different oxidation processes have been investigated for the degradation of the non-steroidal antiinflammatories diclofenac and meclofenamic acid, derived from the model compound 2,6-dichlorodiphenylamine. They include oxidation under photo-Fenton conditions and treatment with organic photocatalysts such as rose Bengal (RB) and triphenylpyrylium (TPP+) salts. The role of the transient species involved in these processes (hydroxyl radical, singlet oxygen and radical cations, respectively) has been investigated by means of photophysical experiments. Based on the obtained results, participation of hydroxyl radical in photo-Fenton degradation appears feasible whereas singlet oxygen has been demonstrated to be unreactive for the degradation of the selected drugs. Finally the photocatalytic activity of triphenylpyrilium salts has been ascribed to electron transfer from the drugs to the triplet excited state of TPP+; ground state complexes have also been observed in this case, although their contribution to the photodegradation process is only marginal. (C) 2013 Elsevier B.V. All rights reserved., Financial support from the Spanish Government (Projects CTQ2009-13699 and CTQ2009-13459-C05-03) and Technical University of Valencia (Programa de Apoyo a la Investigacion y Desarrollo 2775 and Predoctoral FPI fellowship for P. Miro) are gratefully acknowledged.

[EN] The purpose of this study was to find out whether the use of a combination of nanofiltration (NF) and solar photo-Fenton is more efficient than photo-Fenton alone as a tertiary treatment. Five different pharmaceuticals (carbamazepine, flumequine, ibuprofen, ofloxacin, and sulfamethoxazole) dissolved (100 mu g L-1) in natural water were preconcentrated by NF and treated by solar photo-Fenton. Photo-Fenton was operated at pH 5 with 5 mg L-1 of Fe2+. The NF system consists of two membranes operating simultaneously with a total surface area of 5.2 m(2). The photo-Fenton experiments were carried out in a 3 m(2) CPC solar pilot plant with a 35 L total volume. Hydrogen peroxide consumption and the pharmaceutical removal rate were used as the key evaluation parameters. It was demonstrated that at higher initial concentrations of microcontaminants, hydrogen peroxide is used more efficiently and NF pretreatment also reduced the photo-Fenton treatment time. Combined NF and photo-Fenton treatment was therefore found to be a promising approach for wastewater containing extremely low concentrations of microcontaminants. (C) 2012 Elsevier B.V. All rights reserved., Pentair Water Process Technology BV/X-Flow BV (Enschede, The Netherlands) are kindly acknowledged for providing the nanofiltration unit. The authors wish to thank the Spanish Ministry of Science and Innovation for financial support under the EDARSOL Project (Reference: CTQ2009-13459-C05-01).

A mixture of eight phenolic compounds, namely 2,4-dinitrophenol, tannic, ellagic, gallic, protocatechuic, vanillic, syringic and sinapic acids, have been treated by means of a photo-Fenton process under simulated and real sunlight. An experimental design methodology, based in Doehlert matrixes, was employed to check the effect of the concentration of Fe(II) and H2O2, as well as pH. Response surfaces show that photo-Fenton can be extended to pH values clearly above 2.8, probably due to complexation of iron with the phenolic substances. Experiments performed under solar irradiation at pH = 3.9 showed that complete removal of the monitored pollutants was achieved in less than 3 min; mineralisation was also efficient, although some organics remained in the solution. Toxicity was monitored according to Pseudokirchneriella subcapitata and Daphnia magna bioassays; Recombinant Yeast Assay (RYA) was employed to assess estrogenic and dioxin-like activities. 2,4-Dinitrophenol was demonstrated to be the major concern and, in general, photo-Fenton resulted in a detoxification of the solution. Finally, excitation emission matrix (EEM) fluorimetry was employed to obtain complementary information on the behaviour of organic matter. Most peaks associated with the parent pollutants disappeared after short irradiation periods and, at 12 min of irradiation chromophores were destroyed, what can be associated with the removal of complex molecules. (C) 2015 Elsevier B.V. All rights reserved., The authors want to thank the financial support of the Spanish Ministerio de Education y Ciencia (CTQ2012-38754-C03-02) and Generalitat Valenciana (GV/2015/074). Sara Garcia-Ballesteros would like to thank Spanish Ministerio de Economia y Competitividad for her fellowship (BES-2013-066201).

The applicability of photo-Fenton to degrade a mixture of emerging pollutants (EPs) namely amoxycillin, acetaminophen, acetemiprid, caffeine, clofibric acid and carbamazepine has been studied at different scenarios. At high concentrations, acidic photo-Fenton was able to achieve a fast removal of the EPs. Although, complete mineralization was not reached, the toxicity of the solution was decreased according to the respiration of activated sludge and luminescence of Vibrio fischeri assays, although according to this last assay a transitory enhancement of the toxicity was found, attributable to the formation of toxic byproducts such as phenols, chlorophenols and chlorinated pyrydines. Experiments carried out with 5 mg/l of each EP showed that at neutral media the process was two orders of magnitude less efficient than at acidic pH, although it was still able to remove the EPs. The aqueous matrix has a remarkable effect on the process as the presence of humic acids increased the reaction rate and inorganic salts played an inhibitory role. Finally, experiments performed with 10 lg/l of each EP showed that under those experimental conditions nearly complete removal of the EPs was reached with neutral photo-Fenton after 120 min of irradiation; in this case, humic substances played a disfavorable role., We want to thank the financial support of Spanish Ministerio de Ciencia e Innovacion (CTQ 2009-13459-0O5-03) and (CTQ 2009-3459-C05-01).

Photodegradation of dimethoate, alachlor, and pyrimethanil using a thiapyrilium salt (TPTP+) as photocatalyst was performed under simulated sunlight. The photocatalyst removes preferentially pyrimethanil (45% after 60 min of irradiation), followed by dimethoate (20%) and alachlor (13%). In the three cases, an important to moderate decrease of the fluorescence intensity upon addition of the pollutants was observed. The active participation of the singlet excited state in the photodegradation of the pollutants was demonstrated; the corresponding dynamic quenching rate constants were found to be 1.9 x 10(10) M-1 s(-1) (pyrimethanil), 6.7 x 10(9) M-1 s(-1) (dimethoate) and 9.1 x 10(9) M-1 s(-1) Moreover, a decrease in the signal corresponding to the triplet excited state was observed immediately after the laser pulse; again a good correlation was observed between the missing fraction of triplets and the photodegradation rates under solar light. Detection of TPT+, the reduced species derived from the photocatalyst, as well as Rehm-Weller calculations on the free energy changes, strongly support an electron transfer mechanism occurring from the singlet excited state. (C) 2012 Published by Elsevier B.V., Financial support from the Spanish Government (CTQ200913699, CTQ2009-13459-C05-03/PPQ and RIRAAF RETICS), and the Generalitat Valenciana (Prometeo Program and ACOM/2011/173) is gratefully acknowledged.

Water taken from the outlet of a wastewater treatment plant from the South East of Spain has been treated by means of TiO2-based solar photocatalysis. Preliminary analysis showed the presence of significant amounts of nine emerging pollutants (order of magnitude of ng/l): trimethoprim, ofloxacin, enrofloxacin, clarithromycin, acetaminophen, diclofenac, caffeine, thiabendazole and carbamazepine; and trace amounts of another two were detected, namely acetamiprid and erythromycin. Irradiation of the effluent in the presence of TiO2 resulted in a significant removal of all the emerging pollutants, as most of them were detected only at trace amounts after the treatment. In addition to this, percentages of faecal bacteria elimination were close to 100%. Finally, experiments carried out using caffeine as model compound showed that a mild photo-Fenton process might be employed at neutral media in the presence of humic acids, although the performance was worse than photo-Fenton at acidic pH or TiO2.

The reaction kinetics and mechanisms of three neonicotinoid insecticides, imidacloprid (IMD), thiacloprid (THIA) and acetamiprid (ACT), with singlet oxygen and Rose Bengal excited triplet state is reported. The rate constants (5.5 ± 0.5) × 106, (3.9 ± 1) × 107, and (1.3 ± 1) × 106 M−1 s−1 were determined for the chemical reaction of singlet oxygen, and the values (4.8 ± 1) × 107, (1.5 ± 1) × 108, and (3.6 ± 1) × 107 M−1 s−1 for the reactions with Rose Bengal triplet state for IMD, THIA, and ACT, respectively. The most important primary degradation product identified was 6-chloronicotinic acid. The results support a reaction mechanism involving a charge transfer reaction between the insecticides and singlet oxygen or Rose Bengal triplet state. The toxicity of the solutions towards Vibrio fischeri seems not to decrease during the early stages of the reactions. Depletion of the insecticides by singlet oxygen and naturally occurring excited states might be important abiotic pathways involved in natural waters.

The effect of eleven inorganic ions (Cl − , NO 3 − , SO 4 2− ; PO 4 3− , Na + ; NH 4 + , Ca 2+ , Mg 2+ , Zn 2+ , Cu 2+ and Al 3+ ) on the photo-Fenton elimination of pesticides has been investigated. Phosphate and chloride have been demonstrated to have an inhibitory role; on the other hand, the reaction was accelerated in the presence of Cu 2+ , most probably due to a copper-driven Fenton-like process. The solar photo-Fenton treatment of a mixture of four commercial pesticides was studied at pilot plant scale in the presence of chlorides. Samples with coincident dissolved organic carbon (DOC) showed similar chemical composition, which resulted in a comparable biocompatibility, however longer irradiation periods were needed to reach the desired mineralization when Cl − was present. It was demonstrated that the chemical process was able to improve significantly the biocompatibility of the effluent, as shown by the inhibition of respiration of activated sludge, BOD/COD ratio and Zahn–Wellens test.

The reactivity of hydroxyl radicals (HO ) towards three neonicotonoid insecticides, namely imidacloprid, thiacloprid and acetamiprid was investigated. These radicals were generated by photolysis of H(2)O(2) solutions. Flash photolysis experiments were used to determine the rate constants of 5.5 x 10(10) M(-1)s(-1), 6 x 10(10) M(-1)s(-1), and 7.5 x 10(10) M(-1)s(-1), for the reactions of HO with acetamiprid, imidacloprid, and thiacloprid, respectively. Continuous irradiation experiments in the absence and presence of H(2)O(2) allowed the identification and toxicity evaluation of the primary photo- and oxidation products of the insecticides. In all cases, the less toxic 6-chloronicotinic acid was found to be the major product at higher degrees of oxidation. The results reported here indicate that the half life of the insecticides due to their reaction with HO radicals in natural aquatic reservoirs may vary between 5 h and 19 days, and therefore the hydroxyl radical-mediated oxidation may be a significant abiotic elimination route. However, elimination of the insecticide under such conditions might not improve the quality of the contaminated water, as the primary products of degradation still show considerable toxicity to Vibrio fischeri assays.

Degradation of two pesticides, methidathion and carbaryl, has been studied using organic photocatalysts, namely triphenylpyrylium (TPP+), triphenylthiapyrylium (TPTP+) and acridine yellow G (AYG). Experiments carried out using a solar simulator showed that methidathion was more easily photo-oxidised than carbaryl, in all cases. TPP+ and TPTP+ exhibited a better performance than AYG. Detoxification of solutions was related with the primary abatement of the pesticides, as indicated by respirometry studies. Major reaction intermediates were identified by GC–MS, indicating early removal of the carbamate or phosphorated moiety. Photophysical experiments (fluorescence and laser flash photolysis) proved the involvement of an electron-transfer mechanism, most probably from a ground state complex formed between substrate and catalyst.

Experiments based on Vibrio fischeri , activated sludge and Pseudomonas putida have been employed to check variation in the biocompatibility of an aqueous solution of a commercial pesticide, along solar photo-oxidative process (TiO 2 and Fenton reagent). Activated sludge-based experiments have demonstrated a complete detoxification of the solution, although important toxicity is still detected according to the more sensitive V. fischeri assays. In parallel, the biodegradability of organic matter is strongly enhanced, with BOD 5 /COD ratio above 0.8. Bioassays run with P. putida have given similar trends, remarking the convenience of using P. putida culture as a reliable and reproducible method for assessing both toxicity and biodegradability, as a substitute to other more time consuming methods.

A new approach to assess biocompatibility of an effluent, based on combination of different bioassays and chemical analyses, has been tested using a mixture of four commercial pesticides treated by a solar photo-Fenton as target effluent. A very fast elimination of the pesticides occurred (all of them were below detection limit at t30W = 36 min), but mineralisation was a more time-consuming process, due to the formation of organic intermediates and to the presence of solvents, as shown by GC–MS analysis. Measurements based on activated sludge indicated that detoxification was coincident with the removal of the active ingredients, while more sensitive Vibrio fischeri bacterium showed significant toxicity until the end of the experiment, although the effluent might be compatible with biological processes. Biodegradability of the solutions was enhanced by the photochemical process, to reach BOD5/COD ratios above 0.8. Longer time bioassays, such as the Zahn–Wellens' test, support the applicability of coupling photochemical with activated sludge-based biological processes to deal with these effluents.

Biodegradability of a partially photo-oxidized pesticide mixture is demonstrated and the effect of photo-Fenton treatment time on growth and substrate consumption of the bacteria Pseudomonas putida CECT 324 is shown. Four commercial pesticides, laition, metasystox, sevnol and ultracid, usually employed in citric orchards in eastern Spain, were chosen for these experiments. The active ingredients are, respectively, dimethoate, oxydemeton-methyl, carbaryl and methidathion. Judging by biomass measurements, dissolved organic carbon measurements and biodegradation efficiency, it may be concluded that 90mint(30W)110min is the critical point for the photo-Fenton treatment. P. putida is sensitive to photo-produced intermediates giving rise to different kinetic behaviour: longer lag phases, slower growth rates and lower carbon uptake rates. Nonetheless, the percentage of carbon consumption was over 80%, pointing out the biodegradability of the mixture. Biodegradation efficiencies (E(f)) of the photo-reaction intermediates were around 60%, in small 50-ml cultures and in a 12-l bubble column bioreactor. But with the main difference that E(f) in the former took 120h and the same biodegradation was reached in less than 30h in the latter. Therefore, for qualitative results, experiments in flasks might be recommendable, but not for quantitative results for designing purposes.

Triphenylthiapyrylium cation (TPTP + ) has been studied as solar photocatalyst and compared with other organic dyes (triphenylpyrylium, acridine yellow, methylene blue, rosolic acid and alcian blue) using ferulic acid as model pollutant. The best results were obtained with TPTP + (ca. 85% elimination), although important photodegradation was also achieved with acridine yellow and triphenylpyrylium. Concentrations of TPTP + in the range 10–30 mg/l had only a moderate effect on the reaction rate; on the other hand, the concentration of ferulic acid had a remarkable influence on the pseudo-first order rate constant, for which higher values were measured in diluted solutions of the substrate. The results from photophysical studies based on fluorescence quenching and laser flash photolysis were compatible with an electron transfer mechanism. Although the process is thermodynamically feasible from the first singlet excited state, triplet involvement cannot be ruled out at the present stage. The studies were extended to detoxification of Sevnol, a commercial pesticide, based on carbaryl as active ingredient. Total removal of carbaryl was accomplished, although mineralization was only 30%. However, activated sludge respirometry showed that elimination of carbaryl resulted in a complete detoxification of the solution and a significant enhancement of the biodegradability.

Two commercial anionic surfactants, namely sodium dodecylsulfate (SDS) and tetraethylammonium dodecylbenzenesulfonate (DBS), have been submitted to different oxidizing treatments: ozone, ozone at basic pH, sonication, ozone/sonication, ozone/hydrogen peroxide, UV, and UV/ozone. The best results were achieved with O3 /UV and O3 at basic pH where hydroxyl radical is generated; under these conditions, nearly complete elimination of the surfactant was achieved after 10 min of treatment (compared with 50% elimination of DBS and 20% of SDS in ozonation at acidic pH, where molecular O3 is the actual oxidizing agent). The total organic carbon decrease was only moderate and never exceeded 50%. On the other hand, surface tension increased to reach values close to that of distilled water (72 mN/m) in only 15 min of treatment, indicating that ozone is very useful to destroy the species having active surface properties.