Estudio de un proceso de minimización de lodos por ozonación

Una gran cantidad de lodo es producida a partir de procesos de tratamiento biológico aerobio de aguas residuales, lo cual se ha convertido en un serio problema. El tratamiento y la eliminación del exceso de lodo producido a partir de este proceso requieren de altos costos, que pueden representar hasta 65% del total de operación de la planta. Con el fin de reducir el exceso de producción de lodo, nuevos procesos de desintegración que implican métodos mecánicos, químicos, térmicos y biológicos, han sido desarrollados. El objetivo general de este estudio fue caracterizar y optimizar un proceso de minimización de lodo por ozonación en un reactor Batch con tres tipos de lodo: lodo modelo I-XH, lodo modelo II –XP y lodo modelo III Planta Toluca Norte- XI. El lodo modelo uno (mayor XH, microorganismos heterótrofos): cultivado en el laboratorio del CIRA, se instalaron dos reactores que funcionaron como batch secuencial, los cuales se alimentaron con agua sintética, funcionando con un tiempo de retención celular de 15 días y teniendo un volumen útil de 30 L. La purga de estos reactores se recolectó para las pruebas de ozonación. El lodo modelo dos (mayor XP, producto de decaimiento de microorganismos): lodo que fue aerobicamente digerido durante 3 meses. Lodo de la Planta Toluca Norte (presencia adicional de XI, materia orgánica inerte). Para las pruebas de ozonación de lodo se determinaron las dosis y concentración de O3 correspondiente a 1, 2, 3, 4 y 5 minutos de tratamiento; utilizando el Método Colorimétrico Índigo y el Método Yodométrico, el segundo método se utilizó para determinar la concentración de O3 en el gas que proviene del generador con un medidor en línea el cual permitió cuantificar O3 aplicado y capturado en dos trampas de KI al 2%. Para los tres tipos de lodo y para los diferentes tratamientos con y sin O3 (T0, T1, T2, T3, T4 y T5), se determinaron los siguientes parámetros físico-químicos como: temperatura, conductividad eléctrica, turbidez, y potencial de hidrógeno (pH); además se determinaron: SST, SSV, DQO total y DQO soluble. Se incluyeron análisis como diámetro de partícula, fosfatos y respirometría para los tratamientos con O3. La concentración de O3 incrementó de acuerdo al tiempo de tratamiento. Con la ozonación directa el lodo modelo II-XP presentó una concentración especifica de 0.04 a 0.22 g O3/g SSV y el lodo de la PTN-XI tuvo valores de 0.08 a 0.27 g O3/g SSV. El ozono causó lisis celular y la cantidad de sólidos disminuyó al aumentar la concentración de O3, en los tres tipos de lodo. La DQO soluble y la turbidez aumentaron de acuerdo a la concentración de O3 en los tres tipos de lodo ya que, la desintegración y la solubilización de los flóculos generan un gran número de micropartículas dispersas en el sobrenadante, además de sustancias orgánicas solubles. La DQO soluble alcanzó hasta 700% de su valor inicial en los tres tipos de lodo. El tamaño de partícula no se vio afectado por el proceso de ozonación. La actividad biológica para el LMI-XH fue mayor en los tratamientos T0 y T1, debido a que la cantidad de bacterias fue mayor y el alimento estimuló el crecimiento de estas; sin embargo para el T3 y T5 la actividad inicio horas más tarde porque el ozono eliminó una gran cantidad de bacterias y las que sobrevivieron a las dosis de O3 tuvieron actividad, se alimentaron y crecieron. Para el LMII-XP la actividad biológica inicial fue nula debido a que el lodo ya estaba digerido y a las dosis de O3; sin embargo, horas después se presentó actividad y crecimiento microbiano. La actividad biológica para el lodo de la PTN-XI inició horas después de la aplicación de ozono

Factors Determining the Behavior of E-commerce Users According to the Demographic Aspects of College Students

Purpose: E-commerce is a supply of needs typical of the information age. Based on contemporary technologies, it has represented an up-and-coming channel for multiplying the possibilities of supplying demands practically everywhere on the planet. So that it can be constantly improved, scientists and managers have been concerned with better understanding the behavior of online buyers. In this sense, this study aimed to identify the determining factors of e-commerce according to demographic aspects (purchase frequency, income, paid activity, age, and gender) of university students at an institution in the North of Brazil.   Theoretical framework: The study was theoretically based on the factors and variables determining consumer purchasing behavior. Factors as analytical dimensions formed a theoretical architecture, each composed of their respective variables and analysis categories.   Design/Methodology/Approach: The method used was a survey, whose population consisted of 51 students enrolled in the second semester of 2022, from which a sample of 47 respondents was extracted, given that the others dropped out of class. Data were collected with a questionnaire with closed questions, the validity of which was checked with a Cronbach's alpha test at 0.82, considered very compliant. The results were generated using the Mann-Whitney U test, given that the behavior of the variables was not regarded as normal by the Kolmogorov-Smirnov and Shapiro-Wilkens tests. The conclusion points to a kind of virtual democracy in which little differentiation can be seen in the factors determining purchases when taken from the point of view of the demographic variables studied.   Findings: The results showed no differences in the determining factors of e-commerce regarding paid activity, frequency of purchases, and age. A difference in behavior was detected between men and women regarding price and between those with higher incomes and those with lower incomes regarding practicality.   Research, Practical, and Social Implications: The practical implication of the study is that marketing strategies and new product launches offered in the virtual world can be mainly standardized because the demographic differences that impact the behavior of virtual consumers are statistically similar. From a theoretical point of view, the results indicate the need to study other demographic variables to confirm or refute these behavioral uniformities.   Originality/Value: The contribution of this study to the science and practice of electronic commerce is the finding that consumers present similar behaviors when considering the demographic aspects of university students, who represent a large portion of virtual buyers

Impact of extracellular vesicles of Staphylococcus aureus N305 on the immune response of the host

Impact of extracellular vesicles of Staphylococcus aureus N305 on the immune response of the host. STLOpenday

Programa de Extensão em capacidade estatal, segurança e defesa - PECAP

Anais do 35º Seminário de Extensão Universitária da Região Sul - Área temática: EducaçãoO Programa de Extensão em Capacidade Estatal, Segurança e Defesa (PECAP), vinculado ao Grupo de Estudos em Capacidade Estatal, Segurança e Defesa (GECAP), constitui-se como programa articulador de ações de extensão (projetos, cursos, eventos, prestação de serviços e produção acadêmica), conectadas à pesquisa e ao ensino. O programa propõe uma compreensão plural das dinâmicas de relacionamento entre Estado, sociedade e sistema internacional, por meio de uma abordagem interdisciplinar, própria das Relações Internacionais, e da democratização do debate público sobre essas temáticas. A missão principal é construir pontes entre a academia, a sociedade civil, o setor militar, e o governo/setor público de modo a contribuir para a compreensão conjunta de desafios e possibilidades, no Brasil e no mundo, da realização de políticas públicas nas áreas da Capacidade Estatal, Segurança e Defes

Produced Water: An overview of treatment technologies

Produced water is one of the single most significant waste streams in the oil and gas industry, and because it is a residue of complex chemical composition, it can\u27t be simply discarded in the environment, it should receive appropriate treatments before. This paper presents a mapping of the quantitative evolution, referring to the leading publications on the study of water produced with a focus on treatments. A bibliometric method was then adopted to build a structured database with the selected articles and then analyzed the number of publications, countries, areas of impact, authors, keywords, periodicals, and affiliations. The thematic has proved to be an essential line of research over the years. The analysis was considered in the period between 1969 and 2017. Several indicators were observed regarding the development of academic and technological research on water produced as well as its treatment processes. The study was performed in the Scopus database search engine to gather data, and 2434 documents were identified, with 851 articles investigated more specifically. This paper highlights the need for constant future studies about the produced water to minimize not only pollution but also reduce operating costs

Analysis of Project Management Practices Within the Textile and Clothing Industry

The common challenges faced by companies/industries are often related to the ‘iron triangle’ categories, namely: deadlines, budget, scope and quality. The Project Management knowledge area proposes a systematic approach to overcome these difficulties, with the purpose of acquiring new knowledge and skills, as well as by implementing methodologies, tools, processes and techniques. The textile and clothing industry, or fashion industry, is not immune to the same type of challenges. The products of the fashion chain are collections, which are developed according to market specifications, trends and market profiles. These specifications evolve very rapidly and, therefore, have their main objective in the development of new and/or innovative products. To deliver a new collection, the whole process of elaborating these products is executed based on a per project approach. Each collection is unique, having a well-defined beginning and end. The development of a fashion collection should consider the processes that, at the industrial level, will originate the final product, thus requiring a methodology that integrates the development of the project from the initial phase – conception of the product idea – until the final stage – start of production / launch to the market. By trying to identify project management approaches in the Portuguese textile and clothing industry, this study allowed us to conclude that, despite of these organizations considering as being developing or involved in projects, the approaches followed are not formal, structured and systematic. Furthermore, there is still no complete application of any of the known project management methodologie

Estudo de Caso sobre o Ensino-Aprendizagem de Química Mediado em Língua Brasileira de Sinais

Esta pesquisa teve como objetivo investigar as dificuldades do processo de ensino-aprendizagem no ensino de Química mediada na Língua Brasileira de Sinais (Libras) numa escola da rede pública estadual de ensino de Aracaju (SE). A metodologia fundamentou-se na pesquisa estudo de caso com base nas informações coletadas através de questionário semiestruturado aplicado a sete alunos surdos do Ensino Médio, três tradutores/intérpretes de Libras e um professor de Química. Os resultados mostraram que os alunos surdos entrevistados não possuem domínio da Língua Portuguesa escrita, isso gera um grande problema no processo de ensino aprendizagem de modo geral, pois se comunicam apenas pela sinalização necessitando da presença do tradutor intérprete de Libras. As intérpretes de Libras não possuem formação na área de atuação, nem tampouco formação específica com base nos sinais referentes às terminologias químicas, o que contribuiu de forma significativa para ampliar as dificuldades no processo de ensino aprendizagem. E o professor de Química desconhece a função do tradutor Intérprete de Libras nas aulas, não possui conhecimentos em Libras, implicando na falta de comunicação professor-alunos e professor-interpretes. Concluiu-se que é de suma importância minimizar e/ou eliminar as barreiras comunicacionais e pedagógicas no processo de ensino aprendizagem de Química para alunos surdos, mas para isso é necessária uma força tarefa em parceria interativa entre professor de Química e intérpretes de Libras e todos que compõem o espaço escolar, adotando uma metodologia que privilegie também os aspectos visuais