Le psychologue à l’écoute des adolescents tagueurs

Tag et graf font partie des comportements d’appropriation de l’espace urbain des adolescents et ces pratiques de marquage du mur interrogent la société, depuis les politiques jusqu’aux institutions qui s’occupent des jeunes. Nous avons rencontré des collégiens et lycéens pour les questionner sur ces pratiques. Cette enquête nous a permis de mieux comprendre qui sont les adolescents tagueurs et les enjeux que représente le tag pour eux. L’analyse de leur discours s’est avérée particulièrement éclairante sur la coïncidence entre les caractéristiques de cette pratique sociale et les spécificités de l’adolescence. En outre, certaines des constatations issues de cette analyse suggèrent au psychologue clinicien de se mettre à l’écoute de ces adolescents qui s’écrivent dans la rue. Celui-ci peut en effet se saisir du contenu manifeste du marquage du mur pour aller plus loin et engager un travail avec les adolescents tagueurs, s’étayant sur ces marques murales, leurs significations explicites et plus intimes, pour faire émerger l’élaboration et la métaréflexion et participer à la subjectivation.The psychologist as listener for adolescent taggers               Tagging and graffiti are adolescent behaviours related to the appropriation of the urban environment and these wall marking practices disturb society, from the politicians to the institutions responsible for youth. We met school and college students to question them about these practices. This enquiry has given us a better understanding of who the adolescent taggers are and what the tag means to them. Analysing their comments was highly enlightening on the coincidence of this social behaviour and the specificities of adolescence. Furthermore, some of the observations resulting from this analysis suggest that the clinical psychologist should listen to adolescents who write in the streets. They can use the obvious content of what is written on the wall to go further and start to work with adolescent taggers on the basis of these mural markings and their explicit and most intimate significance to lead to elaboration and meta-reflection and participation in subjectivity.El psicólogo a la escucha de los adolescentes « tager »                      Tag y las  graffiti, hacen parte de los comportamientos de apropiación del espacio urbano por parte de los adolescentes. Estas prácticas de « marcado de las paredes » interrogan a muchas personas, desde los políticos a las instituciones que se ocupan de los jóvenes. Hemos encontrado a alumnos de instituto para interrogarles sobre estas prácticas de marcado de las paredes. Unas constataciones resultantes del análisis de los discursos de los sujetos nos permiten, como psicólogo clínico, estar a la escucha de estos adolescentes que se expresan en las calles. Analizando los cuestionarios y las entrevistas, el enfoque psicológico del marcado de las paredes nos abre nuevas perspectivas profesionales : es evidente que para el psicólogo, estos marcados, hechos en las paredes informan sobre los adolescentes y constituyen un punto de anclaje permitiendo entrar en relación con ellos. La psicología clínica invita a apoderarse de este contenido manifiesto para ir mas adelante con el joven tager : el psicólogo puede iniciar un trabajo con el adolescente tager basado en las pintadas murales, sus significados explícitos y mas íntimos para hacer surgir la elaboración y la meta reflexion y participar en la subjetivación

Modelling of submerged membrane bioreactor: Conceptual study about link between activated slugde biokinetics, aeration and fouling process

A mathematical model was developed to simulate filtration process and aeration influence on Submerged Membrane Bioreactor (SMBR) in aerobic conditions. The biological kinetics and the dynamic effect of the sludge attachment and detachment from the membrane, in relation to the filtration and a strong intermittent aeration, were included in the model. The model was established considering soluble microbial products (SMP) formation-degradation. The fouling components responsible of pore clogging, sludge cake growth, and temporal sludge film coverage were considered during calculation of the total membrane fouling resistance. The influence of SMP, trans-membrane pressure, and mixed liquor suspended solids on specific filtration resistance of the sludge cake was also included. With this model, the membrane fouling under different SMBR operational conditions can be simulated. The influence of a larger number of very important process variables on fouling development can be well quantified. The model was developed for evaluating the influence on fouling control of an intermittent aeration of bubbles synchronized or not with the filtration cycles, taking into account the effects of shear intensity on sludge cake removal

Development of a Submerged Membrane Bioreactor simulator: a useful tool for teaching its functioning

Among the technologies used to treat wastewater, the Submerged Membrane Bioreactor (SMBR) has excellent prospects because of the possibility it provides for water reuse. In this work, an SMBR computer simulator is developed. A mathematical model was implemented, which integrated the biological degradation process using activated sludges with the physical separation process using membranes. The simulator functioning was validated with experimental results and its use in teaching was evaluated through the development of a simulated laboratory running for three and a half hours. This gave access to trends and orders of magnitude that would take more than fifteen months to obtain with real experiments. It was successfully used and accepted by the students

Stoichiometry and kinetics of hospital wastewater treatment in a submerged membrane bioreactor

The present article deals with the calibration and validation of a biological model of SMBR for hospi-tal wastewater treatment using respirometry. In a first part, the stoichiometric and kinetic parame-ters are estimated and validated using the experimental oxygen uptake rate (OUR) profiles from the sodium acetate degradation process, according two kinetic theories: one considering that microor-ganisms use the carbon reserve and easily biodegradable substrates simultaneously for growth; and the other that microorganisms use the carbon reserve only when easily biodegradable substrate is depleted. In this study, the first theory proved to be the most adequate to predict the experimental OUR profile. In the second part, the hospital wastewater degradation process simulated using the theory determined as the more suitable. The stoichiometric parameters obtained for acetate were used for the hospital wastewater COD fractionation process, considering simultaneous growth and substrate storage. These COD fractions and the stoichiometric parameters obtained for acetate were employed for the simulation process of hospital wastewater degradation, where only kinetic param-eters were calibrated. Good correspondence was obtained between experimental data and the model outputs. The values obtained for kinetic parameters were different from those obtained for sodium acetate, evidencing the influence of the substrate nature. Through the calibration of stoichiometric and kinetic parameters using the proposed procedure, the activated sludge models proved their capacity and usefulness for the simulation of a hospital wastewater degradation proces

Modelación y optimización de biorreactores con membranas para el tratamiento de aguas residuales

El uso de los biorreactores con membranas (BRM) ha ganado un espacio importante en el tratamiento de aguas residuales urbanas e industriales en los últimos años, debido fundamentalmente a las ventajas que ofrecen sobre los procesos convencionales tales como: mayor calidad del agua, menor impacto ambiental y un mejor control de los procesos. En el presente trabajo se realiza un análisis de la evolución de la modelación de estos sistemas tan complejos, en el que se muestra el gran avance que se ha podido alcanzar en los últimos años en la modelación tanto del sistema biológico como del sistema de filtración. Se destaca, la importancia de la Dinámica Computacional de Fluidos en el estudio del funcionamiento de estos sistemas, específicamente, en el estudio del proceso de colmatación de la membrana. Se explica, además, la tendencia actual al empleo de modelos que integran los procesos de degradación biológic a con la hidrodinámica y los de filtración con membranas, con lo que se logra una descripción más fenomenológica del funcionamiento de los BRM. Por último, se resalta la importancia de los modelos integrados en la optimización de su funcionamiento mediante su implementación a través de herramientas computacionales, lo que permite realizar estudios con un considerable ahorro de recursos y de tiemp

Role of respirometric analysis in the modelling of hospital wastewater treatment by submerged membrane bioreactor

Membrane Bioreactors (MBR) are efficient processes for wastewater treatment since they are compact and deliver a constant quality of treated water even with variable influent composition [1]. More recently they are considered for treating persistent pollutants so-called “emerging contaminants” (pharmaceuticals, pesticides, etc.) that create additional problems due to the effects on the environment and/or their interferences within biological processes [2]. Several studies have demonstrated the capacity of Submerged Membrane Bioreactors (SMBRs) to remove a great variety of pharmaceutical compounds [3]. On the other hand, the efforts for modelling of wastewater treatment systems have always targeted either the biological processes (treatment quality target) as well as the various aspects of engineering (cost and operation). The determination of the biokinetic parameters of these models has been carried out by using systems that treat municipal wastewaters. Considering the simulation of SMBR [4], the purpose of these work is to provide these parameters to adapt an SMBR model fot the treatment of hospital wastewater . In a first part, the behavior and activity of the biomass of sludge from two “sources” were studied simultaneously: the first one from a MBR pilot treating hospital wastewater and the other one from a municipal MBR plant (3000 equivalent inhabitants). The biomass oxygen uptake rate measured while the degradation of an equal volume of hospital wastewater added to each system, showed that there was an adaptation of the first one to the pharmaceutical pollutants while the second one showed a reduction of the oxygen uptake rate, which may be a result either of the inhibition of the degradation process or of the death of part of the microorganisms. Respirometry was used to determine the heterotrophic yields,( ratio of the mass of heterotrophic biomass produced by the mass of easily biodegradable substrate consumed) since it is known to be impacted by the nature of the substrate as well as the population of microorganism carrying out the degradation [5]. The obtained results allowed two remarks: First, the influence of the nature of the sludge on the heterotrophic yield coefficient has been confirmed. In our case YH is close to 0.72 mgCOD/mgCOD for activated sludge used in the hospital wastewater treatment and 0.67 mgCOD/mgCOD for activated sludge used in the urban wastewater treatment. But this comparison is not rigorous and this is the topic of the second point: indeed respirograms of hospital sludge showed a queue that may be related to consumption of nutriment reserves from bacteria [5, 6]. By the way the heterotrophic yields are then over estimated, but the bacterial consortium resistance behavior face to pollution may be interpreted with this nutriments reserve and lowering of the growth yield. These new coefficients and a modified version of the ASM model considering the nutriment reserves were implemented in the SMBR model

Understanding the influence of operating parameters throughin silicooptimization of energy consumption of submerged membrane bioreactor for urban wastewater treatment

Membrane bioreactor technology has become relatively widespread as an advanced treatment for both industrial and municipal wastewaters. The main problem of these installations is that they do not operate at the maximum of their potential, mainly because of membrane fouling. Experimental research with this kind of installation requires resources and is time consuming. The use of a computer simulator, as in the present work, allows the fouling behaviour in a bench-scale submerged membrane bioreactor to be investigated over a wide range of operating parameters: average specific aeration intensity (0.041–0.277 L m−2 s−1), filtration flux (0.032–0.160 m3 m−2 d−1) and filtration and coarse bubble aeration cycles (filtration and aeration times: 60–1080 s, with/without ratio: 0.33/10). A quadratic optimization method applied to the energy consumption (EC) was first carried out: minimum values of 0.27 and 0.32 kW h m−3 were obtained for EC in the sequential and non-sequential operating modes, respectively. Using the optimal operating conditions and the most influent parameters found in the first part, the second part details their influence on both membrane fouling and EC for each operating mode. The mean filtration flux and the mean aeration intensity have opposite effects on fouling and EC, which implies that a more global, economic optimization, including chemical cleaning, is needed. The detailed study of filtration and coarse bubble aeration cycles showed that they had little influence for a with/without ratio superior to 1. Using the quadratic optimization method with in silico experiments gave reliable first approximation results

Utopies corporelles : corps défaillant VS corps augmenté

International audienc

De la violence pubertaire aux blessures auto-infligées

Poster numérique. Colloque " Aux sources de la violence. " FFPP Pari

Pornographie sur Internet et fantasmes pubertaires : le « conteur de Hentaï »

International audienc