Natural magnetite as an effective and long-lasting catalyst for CWPO of azole pesticides in a continuous up-flow fixed-bed reactor.

The global occurrence of micropollutants in water bodies has raised concerns about potential negative effects on aquatic ecosystems and human health. EU regulations to mitigate such widespread pollution have already been implemented and are expected to become increasingly stringent in the next few years. Catalytic wet peroxide oxidation (CWPO) has proved to be a promising alternative for micropollutant removal from water, but most studies were performed in batch mode, often involving complex, expensive, and hardly recoverable catalysts, that are prone to deactivation. This work aims to demonstrate the feasibility of a fixed-bed reactor (FBR) packed with natural magnetite powder for the removal of a representative mixture of azole pesticides, recently listed in the EU Watch Lists. The performance of the system was evaluated by analyzing the impact of H2O2 dose (3.6-13.4 mg L-1), magnetite load (2-8 g), inlet flow rate (0.25-1 mL min-1), and initial micropollutant concentration (100-1000 µg L-1) over 300 h of continuous operation. Azole pesticide conversion values above 80% were achieved under selected operating conditions (WFe3O4 = 8 g, [H2O2]0 = 6.7 mg L-1, flow rate = 0.5 mL min-1, pH0 = 5, T = 25 °C). Notably, the catalytic system showed a high stability upon 500 h in operation, with limited iron leaching (< 0.1 mg L-1). As a proof of concept, the feasibility of the system was confirmed using a real wastewater treatment plant (WWTP) effluent spiked with the mixture of azole pesticides. These results represent a clear advance for the application of CWPO as a tertiary treatment in WWTPs and open the door for the scale-up of FBR packed with natural magnetite.

Propiedades psicométricas de la “Escala de percepción del riesgo para el uso de la tecnología” en niños y adolescentes / Psychometric properties of the “Risk perception scale for the use of technology” in children and adolescents

Los objetivos de esta investigación son: 1) crear un instrumento válido y fiable que permita evaluar la percepción del riesgo que tienen del uso de la tecnología (móvil, Internet y videojuegos) niños y adolescentes; y 2) analizar la frecuencia con la que se dan algunas conductas de riesgo en función de la percepción, el uso de la tecnología y la edad. 807 niños y adolescentes de la provincia de Córdoba (España) respondieron una batería ad hoc que recoge información sobre datos sociodemográficos; uso problemático del móvil, internet y videojuegos; y percepción de riesgo con la “Escala de percepción del riesgo del uso de la tecnología para niños y adolescentes” (EPRUT). Los resultados indican que a partir del análisis factorial, la EPRUT cuenta con tres dimensiones que hacen referencia al móvil, Internet y videojuegos. Se han observado diferencias en función de la edad y la percepción de riesgo. Evaluar la percepción del riesgo favorecerá la detección y el desarrollo de programas de prevención de uso de la tecnología en niños y adolescentes.(AU)

The aim of this work is 1) to create a valid, reliable instrument with which toevaluate the risk perception of children and adolescents regarding their use oftechnology (cell phones, Internet, and video games); and 2) to analyze thefrequency with which some risk behaviors occur in relation to perception,technology use and age. 807 children and adolescents from the province ofCordoba (Spain) answered an ad hoc questionnaire with several instruments:sociodemographic data; problematic use of cell phones, Internet, and video games;and risk perception with the Scale on Risk Perception of Technology Use forchildren and adolescents (SRPTU). The results obtained from the factor analysisreveal that the RPSTU has three dimensions, related to cell phones, Internet, andvideo games, respectively. Differences were observed in the relationship betweenage and risk perception, with older people having the highest risk perception.Assessing risk perception will favor the detection and development of preventionprograms for the use of technology in children and adolescents.(AU)

Photo-Fenton oxidation of cylindrospermopsin at neutral pH with LEDs.

Cylindrospermopsin (CYN) is a potent cyanobacterial toxin found in freshwaters worldwide. In this work, the feasibility of the photo-Fenton process under neutral pH using light emitting diodes as irradiation source for the removal of this hazardous cyanotoxin from freshwater was investigated. The impact of the kind of iron chelating agent (ethylenediamine-N, N'-disuccinic acid vs. ethylenedinitrilotetraacetic acid) as well as the effect of the main operating conditions viz. H2O2 dose, Fe(III) load, initial CYN concentration, and Fe(III):EDDS molar ratio on the performance of the process was systematically evaluated. EDDS was selected as the most appropriate iron chelating agent considering the kinetics of the process and the environmental impact (Vibrio fischeri and Artemia salina). Under optimized conditions ([H2O2] = 30 mg L-1; [Fe(III)] = 5 mg L-1; Fe(III):ligand = 1:0.5 (molar ratio)), complete removal of CYN was achieved in 15-min reaction time. Furthermore, the catalytic system showed to be effective in real water matrices (river and reservoir waters) spiked with CYN. Although the presence of inorganic ions (mainly HCO3-/CO32-) and dissolved organic carbon decreased the oxidation rate of CYN due to scavenging reactions and iron coordination, respectively, complete elimination of the cyanotoxin was achieved in all cases. The fate of EDDS along the process was also evaluated to demonstrate that the catalytic system investigated, apart from its effectiveness, warrants the complete absence of residues after reaction. Therefore, the proposed system constitutes a promising method for cyanotoxin treatment either as a drinking water treatment step in conventional plants or as a potential remediation strategy in the natural environment.

Insights into the degradation of microplastics by Fenton oxidation: From surface modification to mineralization.

This work aims at evaluating the fate of microplastics (MPs) along Fenton oxidation. For such goal, realistic MPs (150-250 µm) of five representative polymer types (PET, PE, PVC, PP and EPS) were obtained from commercial plastic products by cryogenic milling. Experiments (7.5 h) were performed under relatively severe operating conditions: T = 80 °C; pH0 = 3; [H2O2]0 = 1000 mgL-1 (15 doses, 1 every 0.5 h); [Fe3+]0 = 10 mgL-1 (5 doses, 1 every 1.5 h). Slight MPs weight losses (∼10%) were achieved after Fenton oxidation regardless the MP nature. Nevertheless, oxidation yield clearly increased with decreasing the particle size given their higher exposed surface area (up to 20% weight loss with 20-50 µm EPS MPs). Clearly, MPs suffered important changes in their surface due to the introduction of oxygenated groups, which made them more acidic and hydrophilic. Furthermore, MPs progressively reduced their size. In fact, they can be completely oxidized to CO2, as demonstrated in the oxidation of PS nanoplastics (140 nm), where 70% mineralization was achieved. The nature of the plastic particles had a relevant impact on its overall oxidation, being more prone to be oxidized those polymers which contain aromatic rings in their structures (EPS and PET) compared to those formed by alkane chains (PE, PP and PVC). In the latter, the presence of substituents also reduced their oxidation potential. Remarkably, possible leachates released along reaction were more quickly oxidized than the MPs/NPs, so it can be assumed that these dissolved compounds would be completely removed once the solid particles are eliminated. Notably, the leachates obtained upon MPs oxidation were more biodegradable than the released from the fresh solids. All this knowledge is crucial for the understanding of MPs oxidation by the Fenton process and opens the door for the design and optimization of this technology either for water treatment or for analytical purposes (MPs isolation).

Structured Reactors Based on 3D Fe/SiC Catalysts: Understanding the Effects of Mixing.

The application of structured reactors provides a number of advantages in chemical processes. In this paper, two different three-dimensional (3D) Fe/SiC catalysts with a square cell geometry have been manufactured by Robocasting: monoliths (D = 14 and H = 15 mm) and meshes (D = 24 and H = 2 mm) and studied in the catalytic phenol oxidation by hydrogen peroxide (H2O2) for the sustainable production of dihydroxybenzenes (DHBZ). The fluid dynamics, catalytic performance, reaction rates, external mass transport limitation, and catalyst stability have been compared in three different reactors, monolithic fixed-bed reactor, multimesh fixed-bed reactor, and monolithic stirrer reactor, at selected operating conditions. The results show that the mechanical stirring of the 3D Fe/SiC monoliths avoids the external mass transfer limitation caused by the presence of oxygen bubbles in the channels (produced from the HO x · species in autoscavenging radical reactions). In addition, the backmixing has a positive effect on the efficient consumption of H2O2 but an adverse effect on the phenol selectivity to DHBZ since they are overoxidized to tar products at longer contact times. On the other hand, the wall porosity, and not the backmixing, affects the susceptibility of the 3D Fe/SiC catalyst to the Fe leaching, as occurs in the mesh structures. In conclusion, the monoliths operating under plug-flow and external mass transfer limitation in the monolithic fixed-bed reactor (MFB) provide an outstanding phenol selectivity to DHBZ and catalyst stability.

3D-Printed Fe/γ-Al2O3 Monoliths from MOF-Based Boehmite Inks for the Catalytic Hydroxylation of Phenol.

The synthesis of dihydroxybenzenes (DHBZ), essential chemical reagents in numerous industrial processes, with a high degree of selectivity and yield from the hydroxylation of phenol is progressively attracting great interest in the catalysis field. Furthermore, the additive manufacturing of catalysts to produce 3D printed monoliths would provide additional benefits to enhance the DHBZ synthesis performance. Herein, 3D cellular Fe/γ-Al2O3 monoliths with a total porosity of 88% and low density (0.43 g·cm-3) are printed by Robocasting from pseudoplastic Fe-metal-organic frameworks (Fe-MOF)-based aqueous boehmite inks to develop catalytic monoliths containing a Fe network of dispersed clusters (≤5 µm), nanoclusters (<50 nm), and nanoparticles (∼20 nm) into the porous ceramic skeleton. The hydroxylation of phenol in the presence of hydrogen peroxide is carried out at different reaction temperatures (65-85 °C) in a flow reactor filled with eight stacked 3D Fe/γ-Al2O3 monoliths and with the following operating conditions: Cphenol,0 = 0.33 M, Cphenol,0/CH2O2,0 = 1:1 molar, WR = 2.2 g, and space time (τ = W·QL-1) = 0-147 gcat·h·L-1. The scaffolds present a good mechanical resistance (∼1 MPa) to be employed in a catalytic reactor and do not show any cracks or damage after the chemical reaction. DHBZ selectivity (SDHBZ) of 100% with a yield (YDHBZ) of 32% due to the presence of the Fe network in the monoliths is reported at 85 °C, which represents an improved synthesis performance as compared to that obtained by using the conventional Enichem process and the well-known titanium silicalite-1 catalysts (SDHBZ = 99.1% and YDHBZ = 29.6% at 80 °C). This printing strategy allows manufacturing novel 3D structured catalysts for the synthesis of critical chemical compounds with higher reaction efficiencies.

Adsorption of micropollutants onto realistic microplastics: Role of microplastic nature, size, age, and NOM fouling.

This work aims at evaluating the role of nature, size, age, and natural organic matter (NOM) fouling of realistic microplastics (MPs) on the adsorption of two persistent micropollutants (diclofenac (DCF) and metronidazole (MNZ)). For such goal, four representative polymer types (polystyrene (PS), polyethylene terephthalate (PET), polypropylene (PP) and high-density polyethylene (HDPE)) were tested. MPs were obtained by cryogenic milling of different commercial materials (disposable bottles, containers, and trays), and fully characterized (optical microscopic and SEM images, FTIR, elemental analysis, water contact angle and pHslurry). The micropollutants hydrophobicity determined to a high extent their removal yield from water. Regardless of the MP's nature, the adsorption capacity for DCF was considerably higher than the achieved for MNZ, which can be related to its stronger hydrophobic properties and aromatic character. In fact, aromatic MPs (PS and PET) showed the highest adsorption capacity values with DCF (~100 µg g-1). The MP size also played a key role on its adsorption capacity, which was found to increase with decreasing the particle size (20-1000 µm). MPs aging (simulated by Fenton oxidation) led also to substantial changes on their sorption behavior. Oxidized MPs exhibited acidic surface properties which led to a strong decrease on the adsorption of the hydrophobic micropollutant (DCF) but to an increase with the hydrophilic one (MNZ). NOM fouling (WWTP effluent, river water, humic acid solution) led to a dramatic decrease on the MPs sorption capacity due to sorption sites blocking. Finally, the increase of pH or salinity of the aqueous medium increased the micropollutants desorption.

Intimate Partner Aggression Committed by Prison Inmates with Psychopathic Profile.

Psychopathy and intimate partner aggression (IPA) are two concepts that usually appear concomitantly. Male violence toward women is often considered a psychopathic trait that sometimes involves the woman's homicide by her partner and, at other times, attempted homicide. This phenomenon has been studied by conducting interviews following Hare's model with 92 men incarcerated under a compliance regime in a Spanish prison (Córdoba). The results detected six explanatory factors of IPA as a result of attempted homicide or homicide: criminal past and delinquency, impulsivity, the need to stand out from others, lack of empathy, manipulation of others, and instability in partner relationships. The first two factors predict a occurrence of high scores on Hare's Psychopathy Checklist. The results are discussed, and future lines of research are presented, especially focused on the concept of dehumanization and revenge.

The photocatalytic reduction of NO3- to N2 with ilmenite (FeTiO3): Effects of groundwater matrix.

This work analyzes the role of natural groundwater, as well as the effect of HCO3-, Ca2+, Mg2+, K+, SO42- and Cl- concentrations, upon the photocatalytic nitrate reduction using ilmenite as catalyst and oxalic acid as hole scavenger. The nitrate removal and the selectivity towards N2 are significantly limited compared to previous experiments using ultrapure water matrix. Calcium (Ca2+), bicarbonate (HCO3-) as well as pH are claimed as the major controlling factors related to the process yield. Thus, Ca2+ promotes the formation of insoluble oxalate microcrystals, reducing the amount of hole scavenger available. The presence of HCO3- leads to a steeply increase in the pH value, favoring the adsorption onto the ilmenite surface of ions OH-instead of NO3-, NO2- and C2O42. The aforementioned issues are overcome by working with C2O42-/NO3- ratio well above the stoichiometric one, that also maintains the pH value in an acid range. A completed depletion of the starting NO3-, the no detection of either NO2- or NH4+ in the aqueous phase, and a selectivity towards N2 above 95% were achieved using two times the stoichiometric dose.

A comparative study among catalytic wet air oxidation, Fenton, and Photo-Fenton technologies for the on-site treatment of hospital wastewater.

The feasibility of catalytic wet air oxidation, intensified homogeneous Fenton and heterogeneous Photo-Fenton systems for the treatment of real hospital wastewater has been investigated. Wastewater samples were collected from a hospital sewer, during a weekly monitoring program, and fully characterized. Up to seventy-nine pharmaceuticals, including mostly parent compounds and some of their transformation products, were analyzed. Catalytic wet air oxidation allowed the complete removal of several pharmaceutical groups, but it did not allow to eliminate analgesics/anti-inflammatories and antibiotics, whose average removal was around 85%. Intensified Fenton oxidation was the most efficient process for all the drugs removal with an almost complete reduction of the initial pharmaceutical load (99.8%). The heterogeneous Photo-Fenton system reached a 94.5% reduction of the initial pharmaceutical load. The environmental risk of the treated samples by the hazard quotient (HQ) method was also evaluated. Fenton oxidation was the most effective system with a final ∑HQ of 5.4. Catalytic wet air oxidation and Photo-Fenton systems achieved total ∑HQ values of 895 and 88, respectively. This fact was related to the presence of refractory antibiotics in the treated catalytic wet air oxidation samples. On the opposite, the Photo-Fenton system provided the elimination of most pharmaceutical pollutants that pose a high environmental risk such as antibiotics. Simplified cost estimation was finally performed as a preliminary approach of the economy of the three oxidation processes for the hospital wastewater treatment.

Validation of the Sexting Behavior and Motives Questionnaire(SBM-Q).

BACKGROUND: Sexting has garnered interest from the public and the scientific community given its ever-increasing presence in adolescents' lives. However, analysis varies depending on the baseline study used. This calls for a standardised sexting instrument that addresses scientific evidence-based recommendations. The primary aim of this study was to develop and validate the structure of a questionnaire that includes the various sexting behaviours and motives. METHOD: The sample comprised 1,362 students (51.1% female; 12-18 years old). Participants were randomly split into two halves, controlling for the gender variable (n=681), and exploratory and confirmatory factor analyses were performed. RESULTS: Validity of the Sexting Behaviours and Motives Questionnaire (SBM-Q) was confirmed, along with the suitability of the factor structure, internal consistency, and divergent validity. This was also reported by gender. Six dimensions were identified: sending, reasons for sending, receiving, forwarding, victim of forwarding, and reasons for forwarding. CONCLUSIONS: The SBM-Q presents good psychometric properties, providing a detailed and consolidated overview of the behaviours that adolescents might engage in when sexting as well as the context in which it occurs.

Parental Supervision: Predictive Variables of Positive Involvement in Cyberbullying Prevention.

From an increasingly early age, parents face the challenge of educating their sons and daughters to act in the world of offline and online relationships. If for professional educators it is not proving easy, the involvement and guidance of parents in their children's use of the internet seems to be a complex and unexplored challenge. This work aims to analyse the variables that influence digital education and determine a predictive model of positive parental involvement. This study was done with a representative sample consisting of five hundred and ninety-six families (596), representing the parents of children from schools with similar socio-cultural indexes. To do this, and using self-report instruments convertible into independent scales, four predictor variables were analysed: (1) parental knowledge of cyberbullying; (2) perception of parental competence in this regard; (3) parental perception of online risks; and (4) the attribution of parental responsibility in digital education. A structural equations model (SEM) examined the predictive value of these variables with respect to positive parental involvement. The structural equations model confirmed direct and mediated relationships between the independent and mediating variables on the dependent variable: parental supervision. The results indicate that positive parental involvement can be predicted from higher scores in parental knowledge of cyberbullying, perception of parental competence, risk adjustment, and attribution of parental responsibility.

Overview of toxic cyanobacteria and cyanotoxins in Ibero-American freshwaters: Challenges for risk management and opportunities for removal by advanced technologies.

The increasing occurrence of cyanobacterial blooms worldwide represents an important threat for both the environment and public health. In this context, the development of risk analysis and management tools as well as sustainable and cost-effective treatment processes is essential. The research project TALGENTOX, funded by the Ibero-American Science and Technology Program for Development (CYTED-2019), aims to address this ambitious challenge in countries with different environmental and social conditions within the Ibero-American context. It is based on a multidisciplinary approach that combines ecology, water management and technology fields, and includes research groups from Chile, Colombia, Mexico, Peru and Spain. In this review, the occurrence of toxic cyanobacteria and cyanotoxins in freshwaters from these countries are summarized. The presence of cyanotoxins has been confirmed in all countries but the information is still scarce and further monitoring is required. In this regard, remote sensing or metagenomics are good alternatives at reasonable cost. The risk management of freshwaters from those countries considering the most frequent uses (consumption and recreation) has been also evaluated. Only Spain and Peru include cyanotoxins in its drinking water legislation (only MC-LR) and thus, there is a need for regulatory improvements. The development of preventive strategies like diminishing nutrient loads to aquatic systems is also required. In the same line, corrective measures are urgently needed especially in drinking waters. Advanced Oxidation Processes (AOPs) have the potential to play a major role in this scenario as they are effective for the elimination of most cyanotoxins classes. The research on the field of AOPs is herein summarized considering the cost-effectiveness, environmental character and technical applicability of such technologies. Fenton-based processes and photocatalysis using solar irradiation or LED light represent very promising alternatives given their high cost-efficiency. Further research should focus on developing stable long-term operation systems, addressing their scale-up.

Diclofenac photodegradation with the Perovskites BaFeyTi1-yO3 as catalysts.

Perovskite oxides BaFeyTi1-yO3, with y = 0, 0.6, 0.8 and 1, were prepared by ceramic (CM) and complex polymerization methods (CPM) and utilized in UV-LED (365 nm) photocatalytic degradation assays of 25 mg L-1 diclofenac (DIC) model solutions. BaTiO3-CM was also used in the photocatalytic degradation test of a real mineral water for human consumption spiked with 2 mg L-1 DIC. The XRD patterns of the synthesized perovskites showed cubic structure for those prepared by CPM, with distortions of the cubic lattice to hexagonal or tetragonal when prepared by CM, except for BaTiO3. All the perovskites showed good catalytic activity, higher than photolysis, except BaFeO3-CM that presented similar results. BaTiO3-CM and CPM and BaFeO3-CPM were also utilized in UV-LED photocatalytic DIC degradation assays with peroxydisulfate addition. BaFeO3-CPM and BaTiO3-CPM showed better ability to persulfate activation, but the highest mineralization degree was obtained with BaTiO3-CM. This last perovskite was also able to perform DIC degradation in a real matrix. The studied oxides show potentiality for photocatalytic degradation of organic compounds, with or without persulfate addition. A degradation mechanism is proposed.

Validation of the Sexting Behavior and Motives Questionnaire(SBM-Q) / Validación del Cuestionario de Comportamientos y Motivos de Sexting (SBM-Q)

Background: Sexting has garnered interest from the public and thescientifi c community given its ever-increasing presence in adolescents’lives. However, analysis varies depending on the baseline study used.This calls for a standardised sexting instrument that addresses scientifi cevidence-based recommendations. The primary aim of this study was todevelop and validate the structure of a questionnaire that includes thevarious sexting behaviours and motives. Method: The sample comprised1,362 students (51.1% female; 12-18 years old). Participants were randomlysplit into two halves, controlling for the gender variable (n=681), andexploratory and confi rmatory factor analyses were performed. Results:Validity of the Sexting Behaviours and Motives Questionnaire (SBM-Q)was confi rmed, along with the suitability of the factor structure,internal consistency, and divergent validity. This was also reported bygender. Six dimensions were identifi ed: sending, reasons for sending,receiving, forwarding, victim of forwarding, and reasons for forwarding.Conclusions: The SBM-Q presents good psychometric properties,providing a detailed and consolidated overview of the behaviours thatadolescents might engage in when sexting as well as the context in whichit occurs. (AU)

Antecedentes: el sexting ha recibido cada vez mayor atenciónpública y científi ca, dada su creciente presencia en la vida de losadolescentes. Sin embargo, su análisis varía en función del estudio dereferencia. Esto requiere un instrumento de sexting estandarizado queaborde las recomendaciones de la evidencia científi ca. Este estudio tienecomo principal objetivo desarrollar y validar la estructura de un cuestionarioque incluya los diversos comportamientos y motivos de sexting. Método: lamuestra estuvo constituida por 1.362 estudiantes (51,1% chicas; 12-18 años).Se dividió aleatoriamente en dos mitades, controlando la variable género(n=681), y se realizaron análisis factoriales exploratorio y confi rmatorio.Resultados: se confi rmó la validez del Sexting Behaviours and MotivesQuestionnaire (SBM-Q), la adecuación de su estructura factorial, consistenciainterna y validez divergente. También según el género. Concretamente, seidentifi caron seis dimensiones: envío, motivos de envío, recepción, reenvío,víctima de reenvío y motivos de reenvío. Conclusiones: el SBM-Q presentabuenas propiedades psicométricas y permite obtener una visión detallada yconsolidada de los comportamientos que los adolescentes pueden adoptarcuando realizan sexting, así como del contexto en el que sucede. (AU)

Boosting the catalytic activity of natural magnetite for wet peroxide oxidation.

This work explores the modification of naturally occurring magnetite by controlled oxidation (200-400 °C, air atmosphere) and reduction (300-600 °C, H2 atmosphere) treatments with the aim of boosting its activity in CWPO. The resulting materials were fully characterized by XRD, XPS, TGA, TPR, SEM, and magnetization measurements, allowing to confirm the development of core-shell type structures. The magnetite core of the solid remained unchanged upon the treatment whereas the Fe(II)/Fe(III) ratio of the shell was modified (e.g. 0.42, 0.11 and 0.63 values were calculated for pristine Fe3O4, Fe3O4-O400, and Fe3O4-R400, respectively). The performance of the catalysts was tested in the CWPO of sulfamethoxazole (SMX) (5 mg L-1) under ambient conditions and circumneutral pH (pH0 = 5), using the stoichiometric dose of H2O2 (25 mg L-1) and a catalyst load of 1 g L-1. The key role of the ferrous species on the mineral shell was evidenced. Whereas the oxidation of magnetite led to significantly slower degradation rates of the pollutant, its reduction gave rise to a dramatic increase, achieving the complete removal of SMX in 1.5 h reaction time with the optimum catalyst (Fe3O4-R400) compared to the 3.5 h required with the pristine mineral. A reaction mechanism was proposed for SMX degradation, and a kinetic equation based on the Eley-Rideal model was accordingly developed. This model successfully fitted the experimental results. The stability of Fe3O4-R400 was evaluated upon five sequential runs. Finally, the versatility of the catalytic system was proved in real environmentally relevant water matrices.

Sexting Among Adolescents: The Emotional Impact and Influence of the Need for Popularity.

Sexting refers to the exchange of sexual content material via technological devices. The definitions of this phenomenon vary greatly, mainly, depending on the types of sexting: primary and secondary. Besides the above, there is no common perspective on whether sexting is a risk behavior that entails some type of impact by itself or not and, in such a case, whether this impact varies according to gender. In addition, the need to be popular has shown to be a factor that could increase the probability of being involved in sexting. The present study analyzes the potential emotional impact of sexting as well as the effect of the need for popularity on this phenomenon and if it varies according to gender. The sample comprised 2,356 high school students (46.8% female, 53.2% male; age range 11-18 years old, M = 13.72; SD = 1.31) belonging to 12 compulsory secondary education (ESO) schools from the south of Spain. To assess sexting implication, four questions were presented to participants (sending, receiving, forwarding, and receiving sexts via intermediary). Scales, self-report, about emotional impact (depressed, annoyed, and active) and need for popularity were also applied. The results obtained show that, although sexting has a clear emotional impact on adolescents, it does not appear to generate a negative impact among those involved, at least in the short term. Concretely, this phenomenon seems to trigger emotions related to activation in boys and girls (I feel lively, energetic, satisfied, ready, determined, active). Additionally, with respect to the need for popularity, its relevance, specially, in relation to active emotional impact has been confirmed by the analyses. Statistical models found for boys and girls were similar. In addition, some differences in emotional impact by gender were found, girls feeling more depressed and annoyed in secondary sexting, and boys more active regarding both types of sexting.

Coupled heat-activated persulfate - Electrolysis for the abatement of organic matter and total nitrogen from landfill leachate.

This work analyzes the viability of a coupled heat-activated persulfate (PS) and electro-oxidation treatment toabatetheorganic matter and nitrogen from ahigh polluted landfill leachate (5500 mg L-1 TOC; 5849 mg L-1 TN, pH: 8.4). These characteristics makes PS as a suitable oxidant to deal with the recalcitrant organic matter. Under the optimal conditions (70 °C and 60% of the stoichiometric amount of PS), around 60% of the initial organic load was mineralized. On the contrary, the nitrogen removal was below 20%. A subsequent electrolytic stage using Ti/IrO2-TaO2 anode at 175 mA cm-2 and 0.42 M NaCl during 60 min, led to overall organic matter and nitrogen removal above 85% and 90%, respectively, with energy requirement of 38 kWh per kg of nitrogen removed. In this sense, the combined process achieves a significant reduction in terms of energy consumption, up to one fifth in relation to sole electrolysis. These results confirm the feasibility of this combined process to treat landfill leachate.

Degradation of widespread cyanotoxins with high impact in drinking water (microcystins, cylindrospermopsin, anatoxin-a and saxitoxin) by CWPO.

The occurrence of harmful cyanobacterial blooms has unabated increased over the last few decades, posing a significant risk for public health. In this work, we investigate the feasibility of catalytic wet peroxide oxidation (CWPO) promoted by modified natural magnetite (Fe3O4-R400/H2O2), as an inexpensive, simple-operation and environmentally-friendly process for the removal of the cyanotoxins that show the major impact on drinking water: microcystins (MC-LR and MC-RR), cylindrospermopsin (CYN), anatoxin-a (ATX) and saxitoxin (STX). The performance of the system was evaluated under ambient conditions and circumneutral pH (pH0 = 5) using relevant cyanotoxin concentrations (100-500 µg L-1). The nature of the cyanotoxins determined their reactivity towards CWPO, which decreased in the following order: MC-RR > CYN > MC-LR ≫ ATX > STX. In this sense, microcystins and CYN were completely removed in short reaction times (1-1.5 h) with a low catalyst concentration (0.2 g L-1) and the stoichiometric amount of H2O2 (2-2.6 mg L-1), while only 60-80% conversion was achieved with ATX and STX in 5 h. In these cases, an intensification of the operating conditions (1 g L-1 catalyst and up to 30 mg H2O2 L-1) was required to remove both toxins in 1 h. The impact of the main components of freshwaters i.e. natural organic matter (NOM) and several inorganic ions (HCO3-, HPO42-, SO42-) on the performance of the process was also investigated. Although the former led to a partial inhibition of the reaction due to HO· scavenging and catalyst coating, the latter did not show any remarkably effect, and the versatility of the process was finally confirmed in a real surface water. To further demonstrate the effectiveness of the catalytic system, the toxicity of both the initial cyanotoxins and the resulting CWPO effluents was measured with the brine shrimp Artemia salina. Remarkably, all CWPO effluents were non-toxic at the end of the treatment.

Coupled fenton-denitrification process for the removal of organic matter and total nitrogen from coke plant wastewater.

This work assesses the feasibility of applying a Coupled Fenton-Denitrification (CFD) process for the treatment of wastewater from a coking plant. This highly toxic effluent is characterized by comparable carbon and nitrogen contents and it is usually released into the treatment system at well above room temperature. Recalcitrant organic matter can be easily removed in a first step using Fenton treatment. Working at 50 °C, pH0: 3, and a wastewater obtained from a coking plant, the stoichiometric amount of H2O2 relative to COD and a H2O2/Fe2+ weight ratio of 50, around 60% of carbon load was mineralized whereas H2O2 was completely depleted. However, no changes were observed in the total nitrogen content. A subsequent denitrification stage led to an additional 80% TOC (overall above 90%) and 75% Total Nitrogen removal. This was done in a batch bioreactor at room temperature over 72 h, using a 40-day pre-acclimated denitrifying biomass. These results point to the possibility of designing a combined chemical oxidation and biological treatment to deal with complex effluents containing refractory organic matter including high concentrations of nitrogen species.