Critical review of technologies for the on-site treatment of hospital wastewater: From conventional to combined advanced processes

This review aims to assess different technologies for the on-site treatment of hospital wastewater (HWW) to remove pharmaceutical compounds (PhCs) as sustances of emerging concern at a bench, pilot, and full scales from 2014 to 2020. Moreover, a rough characterisation of hospital effluents is presented. The main detected PhCs are antibiotics and psychiatric drugs, with concentrations up to 1.1 mg/L. On the one hand, regarding the presented technologies, membrane bioreactors (MBRs) are a good alternative for treating HWW with PhCs removal values higher than 80% in removing analgesics, anti-inflammatories, cardiovascular drugs, and some antibiotics. Moreover, this system has been scaled up to the pilot plant scale. However, some target compounds are still present in the treated effluent, such as psychiatric and contrast media drugs and recalcitrant antibiotics (erythromycin and sulfamethoxazole). On the other hand, ozonation effectively removes antibiotics found in the HWW (>93%), and some studies are carried out at the pilot plant scale. Even though, some families, such as the X-ray contrast media, are recalcitrant to ozone. Other advanced oxidation processes (AOPs), such as Fenton-like or UV treatments, seem very effective for removing pharmaceuticals, Antibiotic Resistance Bacteria (ARBs) and Antibiotic Resistance Genes (ARGs). However, they are not implanted at pilot plant or full scale as they usually consider extra reactants such as ozone, iron, or UV-light, making the scale-up of the processes a challenging task to treat high-loading wastewater. Thus, several examples of biological wastewater treatment methods combined with AOPs have been proposed as the better strategy to treat HWW with high removal of PhCs (generally over 98%) and ARGs/ARBs (below the detection limit) and lower spending on reactants. However, it still requires further development and optimisation of the integrated processes.

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: C_phenol,0 = 0.33 M, C_phenol,0/C_H2O2,0 = 1:1 molar, W_R = 2.2 g, and space time (τ = W·Q_L^-1) = 0-147 g_cat·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 (S_DHBZ) of 100% with a yield (Y_DHBZ) 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 (S_DHBZ = 99.1% and Y_DHBZ = 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.

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.

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.

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.

Ethnic-Cultural Bullying Versus Personal Bullying: Specificity and Measurement of Discriminatory Aggression and Victimization Among Adolescents

The present study contrasts personal bullying with ethnic-cultural bullying. A representative pluricultural sample from a Spanish adolescent population of Secondary Education took part in the study (N = 27369). The sample filled in the EBIPQ to measure personal bullying. Additionally, they filled in an adaptation of this questionnaire to measure the ethnic-cultural bullying: the EBIPQ-ECD. The EBIPQ-ECD validation showed optimal psychometric properties and a bidimensional structure: ethnic-cultural victimization and ethnic-cultural aggression. The same roles of participation in personal bullying —aggressor, victim, bully/victim, non-involved— were observed in ethnic-cultural bullying, but they did not coincide with each other in a considerable part. Therefore, we concluded that ethnic-cultural bullying is a different phenomenon from personal bullying, with the possibility of certain dynamism existing between both. To prevent and mitigate ethnic-cultural bullying, educational inferences are proposed. We also recommend the use of the EBIPQ-ECD as a tool to evaluate and detect ethnic-cultural aggressions and victimization.

Electro activation of persulfate using iron sheet as low-cost electrode: the role of the operating conditions

This work assesses the role of the operational conditions upon the electro-activation of persulfate (PS) using sacrificed iron electrode as a continuous low-cost Fe²⁺ source. An aqueous phenol solution (100 mg L^-1) was selected as model effluent. The studied variables include current density (1-10 mA cm^-2), persulfate concentration (0.7-2.85 g L^-1), temperature (30-90°C) and the solution conductivity (2.7-20.7 mS cm^-1) using Na₂SO₄ and NaCl as supporting electrolyte. A mineralization degree of around 80% with Na₂SO₄ and 92% in presence of NaCl was achieved at 30°C using 2.15 g L^-1 PS at the lowest current density tested (1 mA cm^-2). Besides PS concentration, temperature was the main variable affecting the process. In the range of 30-70°C, it showed a positive effect, achieving TOC conversion above 95% (using Na₂SO₄ under the previous conditions) along with a significant increase in iron sludge, which adversely affects the economy of the process. A lumped and simplified kinetic model based on persulfate consumption and TOC mineralization is suggested. The activation energy obtained for the TOC decay was 29 kJ mol^-1. An estimated operating cost of US$ 3.00 per m³ was obtained, demonstrating the economic feasibility of this process.

How Much Do Adolescents Cybergossip? Scale Development and Validation in Spain and Colombia

Cybergossip is the act of two or more people making evaluative comments via digital devices about somebody who is not present. This cyberbehavior affects the social group in which it occurs and can either promote or hinder peer relationships. Scientific studies that assess the nature of this emerging and interactive behavior in the virtual world are limited. Some research on traditional gossip has identified it as an inherent and defining element of indirect relational aggression. This paper adopts and argues for a wider definition of gossip that includes positive comments and motivations. This work also suggests that cybergossip has to be measured independently from traditional gossip due to key differences when it occurs through ICT. This paper presents the Colombian and Spanish validation of the Cybergossip Questionnaire for Adolescents (CGQ-A), involving 3,747 high school students (M = 13.98 years old, SD = 1.69; 48.5% male), of which 1,931 were Colombian and 1,816 were Spanish. Test models derived from item response theory, confirmatory factor analysis, content validation, and multi-group analysis were run on the full sample and subsamples for each country and both genders. The obtained optimal fit and psychometric properties confirm the robustness and suitability of a one-dimensional structure for the cybergossip instrument. The multi-group analysis shows that the cybergossip construct is understood similarly in both countries and between girls and boys. The composite reliability ratifies convergent and divergent validity of the scale. Descriptive results show that Colombian adolescents gossip less than their Spanish counterparts and that boys and girls use cybergossip to the same extent. As a conclusion, this study confirmes the relationship between cybergossip and cyberbullying, but it also supports a focus on positive cybergossip in psychoeducational interventions to build positive virtual relationships and prevent risky cyberbehaviors.

Multidimensional Social Competence, Motivation, and Cyberbullying: A Cultural Approach With Colombian and Spanish Adolescents

International research on the risk and protective factors of cyberbullying focus on individual personality variables and the use of technological devices. However, it is necessary to examine in greater depth the interpersonal context as a factor that may influence cyberbullying and the possible differences between cultures. The objective of this article was to analyze the relationship of influence of two interpersonal variables, multidimensional social competence and social motivation, on cyberaggression and cybervictimization through a cultural study of Spain and Colombia, which will permit generalizing the influence of interpersonal variables on cyberbullying in different cultural settings. The sample consisted of 3,830 secondary school students (50.4% Colombian and 49.6% Spanish). Self-reporting measurement instruments validated with different European samples were used. Confirmatory factor analysis (CFA) and structural equation modeling (SEM) were performed. A model of mutual influence revealing the inverse relationship of normative adjustment and the direct relationship of popularity goals in cyberaggression was obtained. Cybervictimization was explained by the direct influence of prosocial behaviors and avoidance goals and the inverse influence of perceived social efficacy, development goals, and social and normative adjustment. As conclusion, this study demonstrates the homogeneity of the Colombian and Spanish models and the important role that the face-to-face context plays in cyberbullying involvement. This article highlights and supports the design of cyberbullying prevention programs, which requires the inclusion of multidimensional social competence and social goals.

Sulfonamides photoassisted oxidation treatments catalyzed by ilmenite

This work assesses the feasibility of several advanced oxidation processes (CWPO Catalytic Wet Peroxide Oxidation), Photocatalysis and their combination (CWPO-Photoassisted process) for sulfonamide antibiotic degradation. Raw ilmenite was used as catalyst in both processes, because of the presence of iron and titanium in its structure. Despite both treatments allowed reaching a total starting antibiotic depletion working at pH₀ = 3 and T₀ = 30 °C within 30 min reaction time, significant differences were observed in terms of mineralization. Thus, whereas photocatalytic process just reduced 35% of initial TOC after 120 min, a 85% of mineralization was reached in the presence of H₂O₂ (CWPO-Photoassisted process) which was related to the oxidation pathway. Only a 35% of mineralization was reached in case of CWPO. In this sense, the degradation route under CWPO-Photoassisted process displayed a mechanism based on the hydroxylation that led to lower molecular weight intermediates. On the contrary, under photocatalysis conditions, the appearance of higher molecular weight intermediates due to organic radical recombination indicates the prevailing of a condensation mechanism.

Nanoscale Fe/Ag particles activated persulfate: optimization using response surface methodology

This work studied the bimetallic nanoparticles Fe-Ag (nZVI-Ag) activated persulfate (PS) in aqueous solution using response surface methodology. The Box-Behnken design (BBD) was employed to optimize three parameters (nZVI-Ag dose, reaction temperature, and PS concentration) using 4-chlorophenol (4-CP) as the target pollutant. The synthesis of nZVI-Ag particles was carried out through a reduction of FeCl₂ with NaBH₄ followed by reductive deposition of Ag. The catalyst was characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM) and Brunauer-Emmett-Teller (BET) surface area. The BBD was considered a satisfactory model to optimize the process. Confirmatory tests were carried out using predicted and experimental values under the optimal conditions (50 mg L^-1 nZVI-Ag, 21 mM PS at 57 °C) and the complete removal of 4-CP achieved experimentally was successfully predicted by the model, whereas the mineralization degree predicted (90%) was slightly overestimated against the measured data (83%).

Enseñanza y Aprendizaje de las Matemáticas: La necesidad de un análisis multidisciplinar

Resumen: El logro y aprendizaje exitoso en matemáticas sigue siendo un desafío a nivel mundial, y se realizan grandes esfuerzos para avanzar en propuestas de mejora, generalmente involucran al profesorado, en términos de su formación, perfeccionamiento o práctica de aula. Los esfuerzos también se orientan hacia el examen del rol de diversas variables o factores que pueden predecir o relacionarse con un mejor nivel de aprovechamiento de esta materia escolar. Todo ello revela el carácter complejo y multifactorial de la enseñanza y aprendizaje de las matemáticas, que obliga a los diversos agentes educativos e investigadores a avanzar y profundizar aún más en su estudio. Con la finalidad de contribuir al examen crítico y empírico de algunas variables contextuales o socio cognitivas asociadas al aprendizaje de las matemáticas o la resolución de problemas, como también al examen de algunas propuestas de innovación en el área y la evaluación de su impacto en algunas competencias o habilidades matemáticas, se presenta un conjunto de trabajos derivados de la investigación de grupos de investigación de amplia y destacada trayectoria en el área. El presente número monográfico de la revista Psychology, Society and Education, reúne un total de diez artículos cuyo objetivo principal es contribuir con evidencia y alternativas de análisis a un área del aprendizaje escolar asociada generalmente con altos niveles de fracaso y emociones negativas. Teaching and Learning of Mathematics: The Need for a Multidisciplinary AnalysisAbstract: Success in learning mathematics remains a global challenge, and great efforts are being made to advance proposals for improvement, generally involving teachers in terms of their training, improvement or classroom practice. Efforts are also oriented toward examining the role of various variables or factors that can predict or relate to a better level of achievement of this school subject. All this reveals the complex and multifactorial nature of the teaching and learning of mathematics, which obliges the various educational agents and researchers to go further and deepen their study. In order to contribute to the critical and empirical examination of some contextual or socio-cognitive variables associated with learning mathematics or problem solving, as well as to the examination of some innovation proposals in the area and the evaluation of their impact on some competences Or mathematical skills, a set of papers derived from the research of research groups of wide and outstanding trajectory in the area is presented. The present issue of the journal Psychology, Society and Education, brings together a total of ten articles whose main objective is to contribute evidence and analysis alternatives to an area of school learning generally associated with high levels of failure and negative emotions.

Validation of the European Cyberbullying Intervention Project Questionnaire for Colombian Adolescents

Cyberbullying is the act of using unjustified aggression to harm or harass via digital devices. Currently regarded as a widespread problem, the phenomenon has attracted growing research interest in different measures of cyberbullying and the similarities and differences across countries and cultures. This article presents the Colombian validation of the European Cyberbullying Intervention Project Questionnaire (ECIPQ) involving 3,830 high school students (M = 13.9 years old, standard deviation = 1.61; 48.9 percent male), of which 1,931 were Colombian and 1,899 Spanish. Confirmatory factor analysis (CFA), content validation, and multigroup analysis were performed with each of the sample subgroups. The optimal fits and psychometric properties obtained confirm the robustness and suitability of the assessment instrument to jointly measure cyber-aggression and cyber-victimization. The results corroborated the theoretical construct and the two-dimensional and universal nature of cyberbullying. The multigroup analysis showed that cyberbullying dynamics are similar in both countries. The comparative analyses of prevalence revealed that Colombian students are less involved in cyberbullying. The results indicate the suitability of the instrument and the advantages of using such a tool to evaluate and guide psychoeducational interventions aimed at preventing cyberbullying in countries where few studies have been performed.

Synthesis of high surface area carbon adsorbents prepared from pine sawdust-Onopordum acanthium L. for nonsteroidal anti-inflammatory drugs adsorption

Chemically activated carbon materials prepared from pine sawdust-Onopordum acanthium L. were studied for the removal of diclofenac and naproxen from aqueous solution. Several carbons, using different proportions of precursors were obtained (carbon C1 to carbon C5) and the chemical modification by liquid acid and basic treatments of C1 were carried out. The textural properties of the carbons, evaluated by N2 adsorption-desorption isotherms, revealed that the treatments with nitric acid and potassium hydroxide dramatically reduced the specific surface area and the pore volume of the carbon samples. The surface chemistry characterization, made by thermal programmed decomposition studies, determination of isoelectric point and Boehm's titration, showed the major presence of lactone and phenol groups on the activated carbons surface, being higher the content when the acidic strength of the carbon increased. Diclofenac and naproxen kinetic data onto C1 carbon followed pseudo-second order model. The adsorption equilibrium isotherms of C1 and the modified carbons were well described by both Sips and GAB isotherm equations. The highest adsorption capacity was found for naproxen onto C1 activated carbon, 325 mg g(-1), since the liquid acid and basic functionalization of the carbon led to a severe decreasing in the adsorption removal of the target compounds.

Impact of the ConRed program on different cyberbulling roles

This article presents results from an evaluation of the ConRed cyberbullying intervention program. The program's impacts were separately determined for the different roles within cyberbullying that students can take, i.e., cyber-victims, cyber-bullies, cyber-bully/victims, and bystanders. The ConRed program is a theory-driven program designed to prevent cyberbullying and improve cyberbullying coping skills. It involves students, teachers, and families. During a 3-month period, external experts conducted eight training sessions with students, two with teachers and one with families. ConRed was evaluated through a quasi-experimental design, in which students from three secondary schools were separated into experimental and control groups. The sample comprised 875 students, aged between 11 and 19 years. More students (n = 586) were allocated to the experimental groups at the specific insistence of the management of all schools; the remainder (n = 289) formed the control. Repeated measures MANOVA showed that cyber victims, cyber aggressors and cyberbully/victims reduced their involvement in cyberbullying. Moreover, cyber-victims and bystanders adjusted their perceptions about their control of personal information on the Internet, and cyber aggressors and bystanders reduced their Internet dependence. The ConRed program had stronger effects on male participants, especially in heightening their affective empathy.

Explanatory model of emotional-cognitive variables in school mathematics performance: a longitudinal study in primary school

This study tested a structural model of cognitive-emotional explanatory variables to explain performance in mathematics. The predictor variables assessed were related to students' level of development of early mathematical competencies (EMCs), specifically, relational and numerical competencies, predisposition toward mathematics, and the level of logical intelligence in a population of primary school Chilean students (n = 634). This longitudinal study also included the academic performance of the students during a period of 4 years as a variable. The sampled students were initially assessed by means of an Early Numeracy Test, and, subsequently, they were administered a Likert-type scale to measure their predisposition toward mathematics (EPMAT) and a basic test of logical intelligence. The results of these tests were used to analyse the interaction of all the aforementioned variables by means of a structural equations model. This combined interaction model was able to predict 64.3% of the variability of observed performance. Preschool students' performance in EMCs was a strong predictor for achievement in mathematics for students between 8 and 11 years of age. Therefore, this paper highlights the importance of EMCs and the modulating role of predisposition toward mathematics. Also, this paper discusses the educational role of these findings, as well as possible ways to improve negative predispositions toward mathematical tasks in the school domain.

Bullying: The impact of teacher management and trait emotional intelligence

BACKGROUND

The bullying phenomenon has serious consequences for those that are involved. In order to find more effective ways to eradicate it from the schools, more research is needed. In this context, teacher management and emotional intelligence (EI) are shown to be relevant keys to consider.

AIM

The aim of this study was to analyse the ways in which teacher management and trait EI affect involvement in bullying aggression and victimization.

SAMPLE

A total of 2,806 Spanish schoolchildren (51.8% girls; Age M = 15.44; SD = 1.79) participated in this transversal study.

METHODS

Self-report questionnaires were administrated; four of the dimensions of the Schoolwide Climate Scale: Bullying victimization; bullying aggression; positive teacher management; and negative teacher management. They also completed the Spanish version of the TMMS-24 EI questionnaire. After encoding the data, six structural equation models were created to study the direct and joint effects of teacher management and trait EI on bullying aggression and victimization. The models were run for both the whole sample and split samples based on the education cycles and sex.

RESULTS

Results showed that both positive and negative teacher management were closely linked to involvement in bullying aggression and victimization. EI was also found to be directly related to bullying involvement. Furthermore, results revealed that teacher management was directly related to trait EI. Education cycle differences were found, but no sex-specific differences were apparent in the sample.

CONCLUSIONS

Conclusions of the study highlight the important role that teacher management plays with regard to bullying involvement and trait EI, and include a discussion of the need to include teacher management in bullying prevention programmes at schools.

Perceived emotional intelligence as a moderator variable between cybervictimization and its emotional impact

The negative effects of traditional bullying and, recently, cyberbullying on victims are well-documented, and abundant empirical evidence for it exists. Cybervictimization affects areas such as academic performance, social integration and self-esteem, and causes emotions ranging from anger and sadness to more complex problems such as depression. However, not all victims are equally affected, and the differences seem to be due to certain situational and personal characteristics. The objective of this study is to analyze the relationship between perceived emotional intelligence (PEI) and the emotional impact of cybervictimization. We hypothesize that EI, which has previously been found to play a role in traditional bullying and cyberbullying, may also affect the emotional impact of cyberbullying. The participants in our study were 636 university students from two universities in the south of Spain. Three self-report questionnaires were used: the “European Cyberbullying Intervention Project Questionnaire,” the “Cyberbullying Emotional Impact Scale”; and “Trait Meta-Mood Scale-24.” Structural Equation Models were used to test the relationships between the analyzed variables. The results support the idea that PEI, by way of a moderator effect, affects the relationship between cybervictimization and emotional impact. Taken together, cybervictimization and PEI explain much of the variance observed in the emotional impact in general and in the negative dimensions of that impact in particular. Attention and Repair were found to be inversely related to Annoyance and Dejection, and positively related to Invigoration. Clarity has the opposite pattern; a positive relationship with Annoyance and Dejection and an inverse relationship with Invigoration. Various hypothetical explanations of these patterns are discussed.

Comparison of Fenton and Fenton-like oxidation for the treatment of cosmetic wastewater

The treatment of cosmetic wastewaters by Fenton (Fe²⁺/H₂O₂) and Fenton-like (Fe³⁺/H₂O₂) oxidation has been studied. From batch and continuous experiments it has been proved that both versions of the Fenton process lead to quite similar results in terms of chemical oxygen demand (COD) and total organic carbon reduction although the COD shows a slightly higher rate in the early stages of reaction. COD reductions of around 55% after 2 h reaction time and 75-80% with 4 h residence time were reached in batch and continuous experiments, respectively, conducted at pH around 3, ambient temperature (20 °C), with 200 mg/L of Fe dose and an initial H₂O₂/COD weight ratio corresponding to the theoretical stoichiometric value. Achieving the locally allowable limit of COD for industrial wastewater discharge into the municipal sewer system takes no more than 30 min reaction time under those conditions by both Fenton systems. However, the Fenton-like process, where iron is fed as Fe(3+), would be preferable for industrial applications since the ferric sludge resulting upon final neutralization of the effluent can be recycled to the process. A second-order kinetic equation with respect to COD fitted fairly well the experimental results at different temperatures, thus providing a simple practical tool for design purposes.

Upper bounds on superpartner masses from upper bounds on the Higgs boson mass

The LHC is putting bounds on the Higgs boson mass. In this Letter we use those bounds to constrain the minimal supersymmetric standard model (MSSM) parameter space using the fact that, in supersymmetry, the Higgs mass is a function of the masses of sparticles, and therefore an upper bound on the Higgs mass translates into an upper bound for the masses for superpartners. We show that, although current bounds do not constrain the MSSM parameter space from above, once the Higgs mass bound improves big regions of this parameter space will be excluded, putting upper bounds on supersymmetry (SUSY) masses. On the other hand, for the case of split-SUSY we show that, for moderate or large tanβ, the present bounds on the Higgs mass imply that the common mass for scalars cannot be greater than 10(11)  GeV. We show how these bounds will evolve as LHC continues to improve the limits on the Higgs mass.

Enhanced Pd pillared clays by Rh inclusion for the catalytic hydrodechlorination of chlorophenols in water

Bimetallic Pd-Rh catalysts supported on pillared clays have been prepared and tested for aqueous-phase hydrodechlorination (HDC) using 4-chlorophenol (4-CP) as target compound. These bimetallic catalysts combine the higher activity of Rh with the better stability of Pd found in previous works with monometallic catalysts. Different combinations of Pd and Rh amounting to 1 wt% total metal load were tested and the catalyst with 0.75 wt% Pd and 0.25 wt% Rh yielded the best results. Ecotoxicity and biodegradability (measured as BOD(5)/COD ratio) of the effluents were checked. A significant decrease of ecotoxicity was observed while biodegradability was dramatically improved from 0.02 for the initial 4-CP solution up to values higher than 0.6.

Selectivity of hydrogen peroxide decomposition towards hydroxyl radicals in catalytic wet peroxide oxidation (CWPO) over Fe/AC catalysts

Two Fe/AC catalysts prepared with different iron precursors (iron nitrate and iron pentacarbonyl) and the same AC support have been tested in H(2)O(2) decomposition in presence and absence of methanol, a known strong scavenger of hydroxyl radicals, to investigate the selectivity towards .OH formation in this reaction and their behavior in the CWPO of phenol. The catalyst prepared with iron nitrate, with the most oxidized surface and the highest Fe surface content, seems to favor a higher selectivity towards .OH formation in CWPO allowing for complete phenol conversion and a significant TOC removal, with the highest mineralization degree at 50 degrees C and atmospheric pressure. Fe/AC catalysts were more efficient in the CWPO of phenol than in methanol presence due to a better use of the oxidant since adsorbed phenol on catalyst surface minimizes inefficient H(2)O(2) decomposition to H(2)O and O(2)(g). The influence of the initial H(2)O(2) concentration on phenol oxidation with this catalyst was also studied. A theoretical stoichiometric amount of H(2)O(2) for complete oxidation of phenol was chosen as the best starting concentration since auto-scavenging reactions can be minimized and it is sufficient for oxidizing phenol and the aromatic intermediates.

Oxidation of cosmetic wastewaters with H(2)O(2) using a Fe/gamma-Al(2)O(3) catalyst

A catalyst based on Fe supported on gamma-Al(2)O(3) has been prepared and tested for catalytic wet peroxide oxidation (CWPO) of cosmetic wastewaters. The influence of the main operating conditions (space-time, temperature, and H(2)O(2) dose) have been investigated. Working with this self-made Fe/gamma-Al(2)O(3) catalyst at 85 degrees C, with a space-time of 9.4 kg(cat) h/kg(COD) and a dose of H(2)O(2), corresponding to 0.5 times the theoretical stoichiometric H(2)O(2)/COD ratio, a substantial COD reduction (around 80%) has been reached with a complete consumption of H(2)O(2). The locally allowable limit of COD for industrial wastewaters discharge to the municipal sewer system can be achieved at lower temperature and space-time. The catalyst showed a high stability in 100 h time on stream tests, where COD and TOC reductions around 82 and 60%, respectively, were maintained working at 85 degrees C and 9.4 kg(cat) h/kg(COD) space-time. Fe leaching from the catalyst upon that time on stream was lower than 3% of the initial load.

CWPO of 4-CP and industrial wastewater with Al-Fe pillared clays

Catalysts based on pillared clays with Al-Fe have been synthesised from a commercial bentonite and tested for catalytic wet peroxide oxidation (CWPO) of aqueous 4-Chlorophenol (4-CP) solution and industrial wastewater from cosmetics manufacture. The effect of the synthesis procedure, the iron load and reaction temperature on the catalytic activity was studied using 4-CP as target compound. A lower temperature in the preparation of the pillaring solution, as well as a higher Fe load, gave rise to a higher catalytic activity, but also a higher leaching of the active phase. The best catalyst, in terms of catalytic activity, was also tested for treating cosmetic wastewater by CWPO. Experiments were carried out at 90 degrees C and atmospheric pressure and the influence of Fe load, catalyst concentration and H(2)O(2)/COD ratio (between 0.5 and 2 times the stoichiometric ratio) were analysed. Higher values of these parameters favour COD reduction. The Fe leaching in all cases was lower than 1.2 mg/L, indicating that these catalysts have a high stability under these experimental conditions.

Pd-Al pillared clays as catalysts for the hydrodechlorination of 4-chlorophenol in aqueous phase

Catalysts based on pillared clays with Pd-Al were synthesized from a commercial bentonite and tested for catalytic hydrodechlorination (HDC) using 4-chlorophenol (4-CPhOH) as target compound and formic acid as hydrogen source. Stable Pd-Al pillared clays, with a strong fixation of the active phase to the solid support were obtained since no Pd was detected in the reaction media. The incorporation of Pd to the pillared clay structure yielded catalysts with high activity in the reaction studied reaching a complete removal of the 4-CPhOH under mild conditions of temperature (50-70 degrees C). Phenol was not the only reaction product formed, since a more hydrogenated product such as cyclohexanone was detected in the effluent, which indicates additional hydrogenation of phenol. The influence of the method of introduction of Pd in the pillared clay (ion-exchange or impregnation) and Pd concentration in the catalytic activity were studied as well as other important operating variables such as reaction temperature, catalyst concentration, 4-CPhOH initial concentration and formic acid to 4-CPhOH molar ratio. The catalysts prepared suffered deactivation after three consecutive runs, probably due to carboneous deposits formation since no appreciable Pd leaching was observed.

Cometabolic biodegradation of 4-chlorophenol by sequencing batch reactors at different temperatures

The simultaneous removal of 4-chlorophenol (4-CP) and phenol in lab-scale sequencing batch reactors at different temperatures has been studied. Phenol feed concentration was fixed at 525 mg/L and 4-CP concentration was increased from 105 to 2100 mg/L at a constant hydraulic residence time (HRT) of 10.5 d. Complete phenol and 4-CP biodegradation was achieved during the aerobic stage working with 4-CP concentrations up to 1470 mg/L in the feed. Both 4-CP and phenol specific initial removal rates were strongly affected by 4-CP feed concentration and temperature. Only at the highest temperature tested (35 degrees C) it was possible to increase the maximum assimilative 4-CP concentration by the biological sludge up to 2100 mg/L, and a significant reduction of the ecotoxicity of the effluents was observed. 4-chlorocatechol (4-CC) was identified as the major intermediate in the aerobic cometabolic 4-CP degradation, being the ecotoxicity of that species substantially lower than that of 4-CP.

Semicontinuous Fenton oxidation of phenol in aqueous solution. A kinetic study

This work investigates the Fenton oxidation of phenol in a semicontinuous reactor where the overall amount of H(2)O(2) is distributed as a continuous feed upon the reaction time. The experiments were carried out at 25 degrees C and atmospheric pressure, with 100mg/L initial phenol concentration and iron dosages from 1 to 100 mg/L. H(2)O(2) aqueous solution was continuously fed during 4h reaction time up to an overall dose varying within the range of 500-5000 mg/L. The results in terms of evolution of phenol, H(2)O(2) and intermediates, as well as TOC abatement were compared with those obtained in conventional batch operation. It was found that the oxidation rates for phenol and intermediates were lower when adding the H(2)O(2) continuously. However, a higher abatement of TOC was reached at the end of the 4-h reaction time, in spite of a similar overall H(2)O(2) consumption. This is the result of a more efficient OH generation throughout the semicontinuous process, favouring the reaction with the organic species and reducing the occurrence of competitive scavenging reactions involving Fe(2+), H(2)O(2) and OH. Two kinetic models were proposed, one for describing the evolution of phenol, aromatics and H(2)O(2) and the other for TOC. The influence of the operating conditions on the kinetic constants was also studied, looking for the optimal conditions in terms of both, environmental and economic points of view.

Hydrodechlorination of 4-chlorophenol in water with formic acid using a Pd/activated carbon catalyst

This work reports on the feasibility of hydrodechlorination as a treatment technique for chlorophenols-bearing wastewaters using formic acid as a hydrogen source. 4-Chlorophenol (4-CPhOH) has been used as target compound and the experiments were carried out in batch and continuous mode with a commercial activated carbon-supported Pd (0.5 wt.%) catalyst. The variables studied in the batch runs were HCOOH/4-CPhOH molar ratio (10-1000), temperature (25-75 degrees C) and catalyst concentration (250-1000 mg/L). The continuous experiments were performed in a fixed bed reactor where aqueous solutions of formic acid and 4-CPhOH with molar ratios between 50 and 100 were continuously fed to the reactor, at different space-time values in the range of 10.7-42.8 kg(cat)h/mol. Reaction temperatures from 35 to 100 degrees C were tested and the pressure was fixed at 2.5bar. Conversion values above 99% for 4-CPhOH were obtained in batch experiments, but using a HCOOH/4-CPhOH molar ratio as high as 500. Moreover, most of the phenol produced was adsorbed on the catalyst. Continuous runs were performed to evaluate the efficiency of the catalyst under lower HCOOH/4-CPhOH ratios and to explore the possibility of converting phenol to more hydrogenated products. The results indicated that the HCOOH/4-CPhOH molar ratios needed were an order of magnitude lower than those required in batch runs to achieve conversions of 4-CPhOH close to 95%. Besides, phenol was not the only reaction product formed, since a more hydrogenated product such as cyclohexanone was detected in the effluent, which indicates additional hydrogenation of phenol in contrast to the behaviour observed in batch experiments. A loss of activity was observed in the continuous runs after 20-30 h on stream.

Evolution of ecotoxicity upon Fenton's oxidation of phenol in water

This work deals with the evolution of intermediates and ecotoxicity upon Fenton's oxidation of phenol in aqueous solution. The EC50 values of the intermediates identified in the oxidation pathway of phenol have been measured. Some of these compounds, mainly hydroquinone and p-benzoquinone, showed toxicity levels much higher than phenol itself. Depending on the operating conditions, these intermediates could be completely transformed into organic acids, mainly oxalic and formic. Ecotoxicity values substantially lower than those expected from the chemical composition were measured in the reaction samples. This is explained by a reduction of the concentration of aromatic intermediates when the pH was adjusted at 6-8 (according to what is required by the standard bioassay ISO 11348-3). Formation of complexes between hydroquinone and p-benzoquinone at increasing pH can remove from solution those highly toxic intermediates whose very low EC50 values give rise to a high ecotoxicity even at fairly low concentrations. This together with the enhanced decomposition of residual H202 at increasing pH represent important beneficial effects of the neutralization step following Fenton treatment which allow a complementary cleaning of the effluent.

Phenol oxidation by a sequential CWPO-CWAO treatment with a Fe/AC catalyst

Catalytic wet peroxide oxidation (CWPO) of phenol with a homemade Fe/activated carbon (Fe/AC) catalyst has been studied in a stainless steel fixed-bed reactor at different operating conditions (T=23-100 degrees C, P(T)=1-8atm, W=0-2.5g, and tau=20-320g(CAT)h/g(Phenol)). The results show that, thanks to the incorporation of Fe on the activated carbon, phenol conversion improved dramatically, reaching a 90% at 65 degrees C, 2atm, and 40g(CAT)h/g(Phenol). However, TOC conversion values remain fairly low, (around 5% at 40g(CAT)h/g(Phenol)), and no improvement was obtained with the inclusion of Fe. The presence of Fe seems to promote the nondesirable coupling reactions that take place in CWPO of phenol due to the condensation of the ring intermediates (the primary phenol oxidation products). These condensation products are quite refractory to CWPO at the conditions employed. Taking advantage of the high phenol conversions in CWPO and the high phenol mineralization in CWAO, along with the good stability of the Fe/AC catalyst, a CWPO-CWAO sequential treatment has been successfully performed by using a fixed-bed and trickle-bed reactor in series. A CWPO treatment at ambient conditions followed by a CWAO treatment at mild conditions (100 degrees C and 8atm) is presented as high efficiency process for the decontamination of phenolic wastewaters.

Application of Fenton oxidation to cosmetic wastewaters treatment

The removal of organic matter (TOC and COD) from a cosmetic wastewater by Fenton oxidation treatment has been evaluated. The operating conditions (temperature as well as ferrous ion and hydrogen peroxide dosage) have been optimized. Working at an initial pH equal to 3.0, a Fe(2+) concentration of 200 mg/L and a H(2)O(2) concentration to COD initial weight ratio corresponding to the theoretical stoichiometric value (2.12), a TOC conversion higher than 45% at 25 degrees C and 60% at 50 degrees C was achieved. Application of the Fenton oxidation process allows to reach the COD regional limit for industrial wastewaters discharges to the municipal sewer system. A simple kinetic analysis based on TOC was carried out. A second-order equation describes well the overall kinetics of the process within a wide TOC conversion range covering up to the 80-90% of the maximum achievable conversion.

Detoxification of kraft pulp ECF bleaching effluents by catalytic hydrotreatment

Two different effluents from the D(1) and E(1) stages of the ECF bleaching of Eucalyptus globulus kraft pulp were treated by catalytic hydrogenation in a trickle bed reactor using commercial and homemade Pd/AC catalysts. The reactor was fed with the bleaching effluent and a H(2)/N(2) gas stream. The variables studied were space-time (1.4-5g(cat)min/mL), gas to liquid flow ratio (286-1000vol.), gas feed concentration (H(2):N(2), 1:1-1:7.3vol.), temperature (25-100 degrees C) and pressure (1-11bar). Hydrotreatment performance was evaluated in terms of ecotoxicity, adsorbable organic halogen (AOX), chemical oxygen demand (COD), biological oxygen demand (BOD(5)) and colour removal. In all the runs, the ecotoxicity of the effluents decreased as a result of the treatment, achieving reductions that ranged from 70% to 98%. Simultaneously to the reduction of toxicity, the hydrotreatment led to a decrease of the colour of the effluents, being the decrease significantly higher in the case of E(1) effluent. The AOX content was reduced by 85% and 23% for E(1) and D(1) effluents, respectively. In the case of D(1) effluent the removal of ecotoxicity was significantly higher than that of AOX, which indicates that much of the toxicity of the effluent must be associated to non-chlorinated organics. In spite of the important reduction of ecotoxicity, the biodegradability of the effluents only increased slightly. The homemade catalysts, prepared from activated carbons with a high external or non-microporous surface area and mesopore volume and a convenient surface chemistry showed a higher efficiency than the commercial one.

Chemical pathway and kinetics of phenol oxidation by Fenton's reagent

Phenol oxidation by Fenton's reagent (H2O2 + Fe2+) in aqueous solution has been studied in depth for the purpose of learning more about the reactions involved and the extent of the oxidation process, under various operating conditions. An initial phenol concentration of 100 mg/L was used as representative of a phenolic industrial wastewater. Working temperatures of 25 and 50 degrees C were tested, and the initial pH was set at 3. The H2O2 and the Fe2+ doses were varied in the range of 500-5000 and 1-100 mg/L, respectively, corresponding to 1-10 times the stoichiometric ratio. A series of intermediates were identified, corresponding mainly to ring compounds and short-chain organic acids. Most significant among the former were catechol, hydroquinone, and p-benzoquinone; the main organic acids were maleic, acetic, oxalic, and formic, with substantially lower amounts of muconic, fumaric, and malonic acids. Under milder operating conditions (H2O2 and Fe2+ at lower concentrations), a great difference was found between the measured total organic carbon (TOC) and the amount of carbon in all analyzed species in the reaction medium. This difference decreased as the doses of H2O2 and Fe2+ increased, indicating that the unidentified compounds must correspond to oxidation intermediates between phenol and the organic acids. To establish a complete oxidation pathway, experiments were carried out using each of the identified intermediates as starting compounds. Dihydroxybenzenes were identified in the earlier oxidation stages. Muconic acid was detected in catechol but not in the hydroquinone and p-benzoquinone oxidation runs; the last two compounds were oxidized to maleic acid. Oxalic and acetic acid appeared to be fairly refractory to this oxidation treatment. A detailed knowledge of the time evolution of the oxidation intermediates is of environmental interest particularly in the case of hydroquinone and p-benzoquinone because their toxicities are several orders of magnitudes higher than that of phenol itself. The time evolution of the intermediates and TOC was fitted to a simple second-order kinetic equation, and the values of the kinetic constants were determined. This provides a simplified approach useful for design purposes.

Evolution of toxicity upon wet catalytic oxidation of phenol

This work reports on the evolution of the toxicity of phenol-containing simulated wastewater upon catalytic wet oxidation with a commercial copper-based catalyst (Engelhard Cu-0203T). The results of the study show that this catalyst enhances detoxification, in addition to its effect on the oxidation rate. The EC50 values of the intermediates identified throughout the oxidation route of phenol have been determined and used to predict the evolution of toxicity upon oxidation. The predicted values have been compared with the ones measured directly from the aqueous solution during the oxidation process. To learn about the evolution of toxicity through out the routes of phenol oxidation, experiments have been performed with simulated wastewaters containing separately phenol, catechol, and hydroquinone as original pollutants. The significant increase of toxicity observed during the early stages of phenol oxidation is not directly related to the development of the brown color that derives mainly from catechol oxidation. This increase of toxicity is caused by the formation of hydroquinone and p-benzoquinone as intermediates, the former showing the highest toxicity. Furthermore, synergistic effects, giving rise to a significant increase of toxicity, have been observed. These effects derive from the interactions among copper leached from the catalyst and catechol, hydroquinone, and p-benzoquinone and demand that close attention be paid to this potential problem in catalytic wet oxidation.

New supersymmetric source of neutrino masses and mixings

Conventionally, neutrino masses in a supersymmetric theory arise from nonrenormalizable lepton-number (L)-violating operators in the superpotential. The alternative possibility of having such operators in the Kähler potential as the dominant source of neutrino masses has very interesting implications and differences with respect to the standard scenario: first, the scale of L violation can be lowered dramatically; second, the renormalization of these operators has remarkable properties: in many cases it improves drastically the stability of neutrino textures against radiative corrections, while in others it makes it possible to generate radiatively large mixing angles in a natural way.

Xanthan gum: production, recovery, and properties

Xanthan gum is a microbial polysaccharide of great commercial significance. This review focuses on various aspects of xanthan production, including the producing organism Xanthomonas campestris, the kinetics of growth and production, the downstream recovery of the polysaccharide, and the solution properties of xanthan.

Sophorolipid production by Candida bombicola: Medium composition and culture methods

Candida bombicola is able to produce sophorolipid molecules with surfactant properties when grown in a medium composed of two different carbon sources (usually sugar and oil) and a nitrogen source (frequently yeast extract). In this work, the composition of the medium and the culture method employed have been studied. The influences of glucose concentration, properties of oil and yeast extract concentration have been taken into account. Accordingly, a production medium composition is proposed (100 g/l glucose, 100 g/l sunflower oil and 1 g/l yeast extract). The most frequent culture methods reported in literature, i.e. batch, medium pulse mode and resting-cell methods, have been tested. The resting-cell method was found to produce the highest final concentration of sophorolipid, obtaining a good yield of carbon sources in a relatively short time. Under the best operational conditions and using the resting-cell method, 120 g/l sophorolipid was obtained in 8 d, with a carbon source yield of 0.60. Product distribution has also been investigated and the sophorolipid molecular structure of opened or cycled molecules has been determined under different operational conditions. Low yeast extract concentration and long fermentation time enhance the production of cycled structures by all the production methods studied.