Resumen Contexto: La electrocoagulación (EC) se ha convertido en un proceso viable que permite reutilizar las aguas residuales industriales, mediante un reactor eléctrico. Esta técnica aplica los fundamentos de la coagulación y floculación permitiendo la reutilización de estas aguas. Objetivo: Este estudio pretende evaluar la eficiencia de la técnica de EC para el tratamiento de aguas residuales mixtas provenientes de la industria de lácteos y cárnicos (ARLC). Metodología: El agua residual utilizada para esta investigación fue obtenida del efluente de la planta de productos lácteos y cárnicos de la Universidad Popular del Cesar (UPC). Se investigó el efecto de dos variables de diseño de un electrocoagulador tipo Bach rectangular, sobre las características fisicoquímicas de las ARLC durante el proceso de EC: número de electrodos y tiempo de tratamiento. Las características del agua residual utilizadas como indicadores de la eficiencia de tratamiento del electrocoagulador fueron DQOtotal, DQOsoluble, conductividad eléctrica, pH y turbiedad. La variable de diseño del electrocoagulador referente a número de electrodos consistió en tres montajes de 3, 6 y 13 electrodos de hierro conectados en paralelo, energizados con una fuente de corriente directa (DC) de 360 W, a un voltaje constante de 12 V. La variable de tiempo de tratamiento fue máxima de 60 minutos con evaluación de los indicadores de las aguas residuales cada 15 minutos. Resultados: Durante los experimentos de EC, la configuración de 13 electrodos en paralelo fue la mejor para el tratamiento de las ARLC, lo que permitió la remoción de DQOtotal, DQOsoluble, y turbiedad, con eficiencia máxima de reducción de 96 %, 95 % y 94 %, respectivamente. Contrariamente, la EC aumentó los valores de conductividad eléctrica, corriente y pH, de los cuales se obtuvieron valores medios finales de 2785 µS cm-1, 11,6 A y 12,63, respectivamente. Conclusiones: El sistema de electrocoagulación tipo Bach rectangular demostró ser eficiente durante su operación con 13 electrodos y 60 minutos de retención durante el tratamiento de las ARLC. Financiamiento: Universidad Popular del Cesar (UPC), Grupo de Investigación Estudios Sanitarios y Ambientales (ESA).

Abstract Context: Electrocoagulation (EC) has become a viable process that allows minimizing the contaminant loadings in the industrial wastewater, through electrodes arranged on an electrical reactor. This technique applies the coagulation-flocculation fundaments, allowing water reuse on an industrial scale. Objective: This study seeks to assess the efficiency of the EC technique for the treatment of mixed wastewater originated in the dairy and meat industry (DMWW). Materials and Methods: The wastewater used in the study was obtained from meat and dairy products plant effluents of the Popular University of Cesar (UPC). The effect of two design variables of the rectangular Bach-type electrocoagulation system was assessed on the physicochemical characteristics of the DMWW during the EC process: the number of electrodes and treatment time. The wastewater characteristics used as indicators of the treatment efficiency from electro-coagulator were CODtotal, CODsoluble, electric conductivity, pH, and Turbidity. The design variable of the electrocoagulation system related to the number of electrodes consisted of three configurations, 3, 6, and 13 iron electrodes connected in parallel. The electrodes were energized with a source of direct current (DC) to 360 Watts and a constant voltage of 12 V. The treatment time variable was a maximum of 60 minutes with evaluation of the wastewater indicators every 15 minutes. Results: During the EC experiments, the design configuration of 13 parallel electrodes and 60 minutes was the best for the DMWW treatment. This electrocoagulation design configuration system allowed the reductions of CODtotal, CODsoluble, and turbidity with maximum reduction efficiency of 96%, 95%, and 94%, respectively. On the other hand, EC increased the electrical conductivity, current, and pH values, obtaining final mean values of 2785 µS cm-1, 11,6 A y 12,63, respectively. Conclusions: The rectangular Bach-type electrocoagulation system proved to be efficient during its operation with 13 electrodes and 60 minutes of retention for the DDWW treatment. Funding: Popular University of Cesar (UPC) / Research group of Sanitary and Environmental studies - E.S.A.

Abstract The need to promote the management of solid waste generated in the municipality of Pelotas-RS allowed a partnership of the municipal sanitation agency with educational institutions of the municipality, through the Adopt a School Project (AUE), aiming to advance the selective collection of recyclable waste in the different neighborhoods of the city. Given the time of operation of the AUE, the study seeks to carry out an evaluation and diagnosis on the situation of the AUE concerning the management of solid waste recyclable in 62 educational institutions of the public and private network. A quantitative exploratory-descriptive survey was conducted, using a structured questionnaire. The results showed a significant increase in the number of participating schools, showing that municipal elementary schools stood out in working on the issue of solid waste through the Chi-Squared test (P < 0,05). In addition to inadequate waste segregation, lack of infrastructure, and gaps in environmental education practices in schools. Considering that, despite the limitations, the project contributes to the improvement of the management of solid recyclable waste in educational institutions and assists in municipal selective collection, in addition to strengthening public policies in the area of environment and education, assisting in the process of citizen training and the construction of environmental sustainability.

Resumo A necessidade de promover a gestão dos resíduos sólidos no município de Pelotas-RS permitiu uma parceria do órgão de Saneamento com instituições de ensino do município, através do Projeto Adote Uma Escola (AUE), visando avançar na coleta seletiva de resíduos recicláveis nos diferentes bairros da cidade. Haja vista o tempo de atuação do AUE, o objetivo foi realizar uma avaliação sobre a situação do AUE em relação ao gerenciamento dos resíduos sólidos recicláveis em 62 instituições de ensino da rede pública e privada. Foi realizada uma pesquisa quantitativa exploratório-descritiva, através de questionário estruturado. Os resultados revelaram crescimento significativo (teste Qui-Quadrado com P < 0,05) do número de escolas, evidenciando que as escolas de ensino fundamental se destacaram em trabalhar a temática dos resíduos sólidos. Além da segregação inadequada dos resíduos, carências na infraestrutura e a existência de lacunas na realização de práticas de educação ambiental nas escolas. Considera-se que, apesar das limitações, o projeto contribui para a melhoria do gerenciamento dos resíduos sólidos recicláveis nas instituições e auxilia na coleta seletiva, além de fortalecer as políticas públicas de meio ambiente e educação, auxiliando no processo de formação de cidadãos e na construção da sustentabilidade ambiental.