Abstract (Introduction): The search for techniques and methods for managing sludge generated during wastewater treatment is necessary to ensure sustainable sanitation in the medium term in Latin America. An interesting approach involves converting sludge into a biosolid usable in agriculture through alkaline sanitization. (Objective): We evaluated this technique’s efficacy and economic and environmental viability for obtaining an agriculturally usable type A biosolid from municipal wastewater treatment plant (WWTP) sludge. (Methodology): To this end, the efficacy in reducing microbiological parameters was experimentally tested at the laboratory scale using quicklime, for anaerobic and aerobic WWTP sludge. The experimental results fed a benefit/cost analysis model and a life cycle assessment. (Results): It was confirmed that applying a 40 % lime dose allowed the obtention of a type A biosolid with non-detectable concentrations of pathogenic microorganisms, which remained in that condition for more than 30 days. Additionally, the benefit/cost and life cycle analyses concluded that this option would be more attractive than sludge disposal in a landfill, due to the corresponding savings in chemical compounds (fertilizers, agricultural lime). (Conclusions): Therefore, alkaline sanitization can be considered suitable for WWTP sludge management. Its application on a larger scale should be further investigated in the country and the Latin-American region, considering the risk associated to the presence of heavy metals too.

Resumen (Introducción): La búsqueda de técnicas y modelos de gestión del lodo generado durante el tratamiento de las aguas residuales es necesaria para garantizar un saneamiento sostenible a mediano plazo en América Latina. Una vía interesante consiste en convertir el lodo en un biosólido aprovechable en la agricultura por medio de la higienización alcalina. (Objetivo): Se evaluó la eficacia y la viabilidad económica y ambiental de esta técnica para la obtención de un biosólido tipo A aprovechable en la agricultura a partir de lodo de planta de tratamiento de aguas residuales (PTAR) ordinaria. (Metodología): Para ello se probó experimentalmente en escala de laboratorio la eficacia en el decaimiento de parámetros microbiológicos higienizados con cal viva, usando lodo anaeróbico y aeróbico de PTAR. Los resultados experimentales alimentaron un modelo de análisis de beneficio/costo y de ciclo de vida. (Resultados): Pudo corroborarse que la aplicación de dosis de cal de 40 % permitió obtener un biosólido tipo A con concentraciones de microorganismos patógenos no detectables, lo cual se mantuvo en esa condición por más de 30 días. Además, el análisis de beneficio/costo y de ciclo de vida permitieron concluir que esta opción sería más atractiva que la disposición del lodo en un relleno sanitario, debido al ahorro correspondiente en compuestos químicos (fertilizantes o cal agrícola) derivado de su aprovechamiento. (Conclusiones): Por lo tanto, la técnica de higienización alcalina puede considerarse como adecuada para la gestión del lodo de PTAR y su aplicación a mayor escala debe investigarse en mayor detalle en el país y la región latinoamericana, considerando también el riesgo de presencia de metales pesados en este subproducto.

Abstract In Costa Rica, there are significant challenges regarding wastewater treatment. This study evaluated the management of municipal wastewater in Costa Rica, with emphasis on the technological profile, the use of anaerobic systems, and the recovery of generated by-products. A mixed approach was used, combining secondary information from databases, expert consultations, and participatory workshops. It was found that most existing systems work with activated sludge and direct discharge to receiving bodies. Additionally, significant gaps were identified for the implementation of anaerobic systems for wastewater treatment. From a technical standpoint, the lack of training and confidence in designing and operating these systems was noted, along with the relevance of controlling the treatment of emerging contaminants. From an economic standpoint, the lack of financial sustainability of projects, low capacity for user payment, and lack of incentives or tiered tariff systems were identified. Within institutional gaps, the main issue was the need for clearer sectoral leadership and avoiding duplication of functions. All the above requires robust and clear regulations that allow for innovation in the systems to be implemented. Finally, it was found that, for the circular economy principle to become a reality, cultural change is required, and the paradigm that wastewater is only meant for disposal must be changed.

Resumen En Costa Rica, existen grandes desafíos en materia de tratamiento de aguas residuales. Este trabajo evaluó la gestión de aguas residuales ordinarias en Costa Rica, dando énfasis al perfil tecnológico, al uso de sistemas anaeróbicos y a la recuperación de los subproductos generados. Se consideró un abordaje mixto, combinando información secundaria de bases de datos, consultas a expertos y talleres participativos. Se logró evidenciar que la mayoría de los sistemas que existen trabaja con lodos activados y con vertido directo a cuerpo receptor. Además, se evidenciaron brechas importantes para la implementación de los sistemas de tratamiento de aguas residuales, en especial para los sistemas anaeróbicos. Desde el punto de vista técnico, se identificó la falta de capacitación y de confianza en diseñarlos y operarlos, aunado a la relevancia de controlar el tratamiento de contaminantes emergentes; desde el punto de vista económico, se apunta hacia la falta de sostenibilidad financiera de los proyectos y poca capacidad de pago de los usuarios, falta de incentivos o de sistemas tarifarios escalonados; dentro de las brechas institucionales, la principal es la necesidad de tener una rectoría más clara del sector y evitar la duplicidad de funciones. Se demostró que lo anterior requiere ir ligado de una normativa robusta y clara, que permita la innovación en los sistemas a implementar. Finalmente, se pudo detectar que, para que el principio de economía circular sea una realidad, se requiere trabajar en un cambio cultural y en romper el paradigma de que las aguas residuales solo sirven para desecharlas.

ABSTRACT Objective: To describe the clinical and demographic characteristics of patients hospitalized with diabetic foot complicated with infection in the medical clinic service of the Regional Hospital of Coronel Oviedo, Paraguay during the year 2021. Materials and methods: A cross-sectional descriptive observational study was carried out, with non-probabilistic sampling of consecutive cases of patients over 18 years of age diagnosed with diabetic foot admitted to the medical clinic service of the Regional Hospital of Paraguay during the year 2021, where the Variables were age, Wagner grade, first and second targeted antibiotic, and type of surgical procedure. Results: 76 patients were included, 57% were male. According to the Wagner classification, 36 patients (47%) had a Wagner grade IV and 20 patients (26%) had a Wagner grade III. Treatment was conservative in 53% (n=41). 30% (n=23) required phalangeal amputation and 6% (n=5) required infracondylar amputation. Conclusion: Most of them were male, in turn most of them were Wagner grades III and IV. Among patients who required surgery, phalangeal amputations were the most common procedure. Regarding therapeutic treatment, the use of beta-lactams and anaerobic medications predominated.

RESUMEN Objetivo: Describir las características clínicas y demográficas de los pacientes internados con pie diabético complicada con infección en el servicio de clínica médica del Hospital Regional de Coronel Oviedo, Paraguay durante el año 2021. Materiales y métodos: Se realizó un estudio observacional descriptivo de corte transversal, con muestreo no probabilístico de casos consecutivos de pacientes mayores de 18 años diagnosticados con pie diabético internados en el servicio de clínica médica del Hospital Regional de Paraguay durante el año 2021, donde las variables fueron la edad, grado de Wagner, primer y segundo antibiótico dirigido y tipo de procedimiento quirúrgico. Resultados: Fueron incluidos 76 pacientes, el 57% fue del sexo masculino. De acuerdo con la clasificación de Wagner 36 pacientes (47%) tenían un grado de Wagner IV y 20 pacientes (26%) un grado de Wagner III. El tratamiento fue conservador en el 53% (n=41). El 30% (n=23) requirió amputación de las falanges y el 6% (n=5) requirió amputación infracondílea. Conclusión: En su mayoría fueron del sexo masculino, a su vez en su mayoría fueron los grados III y IV de Wagner. Entre los pacientes que necesitaron cirugía, las amputaciones de falanges fueron el procedimiento más común. En cuanto al tratamiento terapéutico predominó el uso de betalactámicos y medicamentos anaeróbicos.

ABSTRACT: Increasing the cup score is crucial in coffee quality, which can be achieved by modifying the fermentation. The effect of double fermentation of coffee (Coffea arabica) on bean quality was evaluated. De-pulped Catucaí cherry trees were subjected to double fermentation, followed by washing and drying. The double fermentation was carried out under anaerobic and aerobic conditions, at room temperature (22.8 °C) and cold (13.2 °C) using four treatments and a control; during fermentation, pH, titratable acidity and °Brix were evaluated; and in the dried beans, yield, granulometric analysis and sensory quality were evaluated. The results showed a pH of 3.2 to 3.9, titratable acidity of 0.5% and 1.7% and °brix between 4 and 5.5; the average yield was 83.04%, grain retention on mesh 15 of 89.32% and a very good rating in sensory quality in all treatments (scores greater than 82 on the SCAA scale). The highest cup score was achieved by treatment with anaerobic fermentation at room temperature (84.25 points), whose characteristic notes were chocolate, orange, cinnamon and almond. The results show that all the coffees treated with double fermentation achieved higher scores than the control.

RESUMEN: Incrementar el puntaje en taza es crucial en la calidad del café, que puede lograrse modificando la fermentación. Se evaluó el efecto de la doble fermentación del café (Coffea arábiga) en la calidad del grano. Los cerezos variedad Catucaí despulpados fueron sometidos a doble fermentación, seguido de lavado y secado. La doble fermentación se realizó en condiciones anaeróbicas y aeróbicas, a temperatura ambiente (22,8 °C) y en frío (13,2 °C) utilizando cuatro tratamientos y un control; durante la fermentación se evaluó el pH, acidez titulable y °Brix; y en los granos secos rendimiento, análisis granulométrico y calidad sensorial. Los resultados mostraron un pH de 3,2 a 3,9, acidez titulable de 0,5% y 1,7% y °brix entre 4 a 5,5; el rendimiento promedio fue 83,04%, retención de grano sobre malla 15 de 89,32% y una calificación de muy buena en calidad sensorial en todos los tratamientos (puntajes superiores a 82 en escala SCAA). El mayor puntaje en taza alcanzó el tratamiento con fermentación anaeróbica a temperatura ambiente (84,25 puntos), cuyas notas características resaltantes fueron a chocolate, naranja, panela y almendra. Los resultados demuestran que todos los cafés tratados con doble fermentación alcanzaron puntajes mayores que el control.

ABSTRACT Introduction: The fish processing industry generates large volumes of wastewater, which are generally treated in lagoons, generating bad odors and emitting polluting gases into the atmosphere. According to their organic matter content, these can be treated in anaerobic reactors with a microalgae coupling for the bioremediation of the effluent, due to their high N, P and CO2 removal capacity. Objective: To determine the potential of fish processing wastewater from the fishing industry in Sancti Spíritus for biogas and microalgae production. Materials and Methods: The physicochemical characteristics of the wastewater are taken as a starting point and mass balances are performed using indexes from the literature to determine the volumes of biogas and the amount of biomass harvested from the microalgae Chlorella vulgaris. Results and Discussion: The analyzed waters represent a potential for obtaining biogas and for the development of microalgae cultures as a promising alternative to improve process performance, which allows obtaining energy and high value-added products. Conclusions: The wastewater from the Pescaspir fishing company produces 21.8 m3 of biogas per day and 0.58 kg/d of dry microalgal biomass, so the proposed treatment system allows the generation of renewable energy, the production of biomass, obtaining a purified effluent and reducing the environmental impact on natural aquatic systems, in addition to other possible technological applications.

RESUMEN Introducción: La industria de procesamiento del pescado genera grandes volúmenes de aguas residuales, que generalmente son tratadas en lagunas, generando malos olores y emitiendo gases contaminantes a la atmósfera. De acuerdo a su contenido de materia orgánica estas pueden ser tratadas en reactores anaerobios con un acople de microalgas para la biorremediación del efluente, debido a su alta capacidad de remoción de N, P y CO2. Objetivo: Determinar el potencial de las aguas residuales del procesamiento de pescado de la industria pesquera en Sancti Spíritus para la producción de biogás y microalgas. Materiales y Métodos: Se toma como punto de partida las características fisicoquímicas de las aguas residuales y se realizan balances de masa empleando índices de la literatura, para determinar los volúmenes de biogás y la cantidad de biomasa cosechada de la microalga Chlorella vulgaris. Resultados y Discusión: Las aguas analizadas, representan un potencial para la obtención de biogás y para el desarrollo de cultivos de microalgas como alternativa prometedora para mejorar el rendimiento de los procesos, lo que permite obtener energía y productos de alto valor añadido. Conclusiones: Las aguas residuales de la empresa pesquera Pescaspir, permiten obtener 21,8 m3 de biogás al día y 0,58 kg/d de biomasa microalgal seca, por lo que el sistema de tratamiento propuesto permite la generación de energía renovable, la producción de biomasa, la obtención de un efluente depurado y la reducción del impacto ambiental que causan en los sistemas acuáticos naturales, además de otras posibles aplicaciones tecnológicas.

ABSTRACT Introduction: In Cuba, there is a tendency to decentralize productions with the creation of livestock modules where different livestock species coexist, such as swine, cattle and poultry. In this context, anaerobic digestion (AD) is an alternative for the decarbonization of the agricultural sector, since it generates energy during waste treatment. Objective: To evaluate the AD of swine manure (SM) and poultry manure (PM) with cattle manure (CM) in terms of biochemical methane potential (BMP), and kinetic parameters in mono and co-digestion. Materials and Methods: The trial was conducted in 2 L reactors at 27 °C (average). The BMP of SM, PM and CM was determined in mono-digestion, and then with addition of 15, 30 and 45 % of CM, to the PM40:SM60 mixture. To describe the kinetic behavior of the process, experimental data were fitted to three first and second order models. Results and Discussion: The experimental BMP with CM addition was higher than expected, with increase between 26-31 %, demonstrating the synergy of the mixtures; since the C/N ratio and the methanogenic archaeal community were improved. The models were adjusted to the experimental data with adjusted coefficients of determination higher than 90 %. Conclusions: The addition of CM increased the experimental methane yield over the expected one. The Hill model shows a maximum yield of 369 LCH4/kgVS for mixtures with 15 and 30 % CM. The best variant was with 15 %, and it is necessary to transport manure from 20 cows to the biodigester.

RESUMEN Introducción: En Cuba, existe tendencia a descentralizar producciones con la creación de módulos pecuarios donde coexisten diferentes especies de ganado, como porcino, vacuno y avícola. En este contexto, la digestión anaerobia (DA) resulta una alternativa para la descarbonización del sector agropecuario, ya que genera energía durante el tratamiento de residuales. Objetivo: Evaluar la DA de estiércol porcino (EP) y gallinaza (EG) con estiércol vacuno (EV) en términos del potencial bioquímico de metano (PBM), y parámetros cinéticos en mono y codigestión. Materiales y Métodos: El ensayo se realizó en reactores de 2 L a 27 ºC (promedio). Se determinó el PBM del EP, EG y EV en monodigestión, y luego con adición de 15, 30 y 45 % de EV, a la mezcla EG40:EP60. Para describir el comportamiento cinético del proceso, se ajustaron los datos experimentales a tres modelos de primero y segundo orden. Resultados y Discusión: El PBM experimental con adición de EV fue superior al esperado, con incremento entre 26-31 %, demostrando la sinergia de las mezclas; ya que se mejoró la relación C/N y la comunidad de arqueas metanogénicas. Los modelos se ajustaron a los datos experimentales con coeficientes de determinación ajustado superiores al 90 %. Conclusiones: La adición de EV aumentó el rendimiento de metano experimental respecto al esperado. El modelo de Hill muestra un rendimiento máximo de 369 LCH4/kgSV para las mezclas con 15 y 30 % de EV. La mejor variante fue con 15 %, y se necesita transportar estiércol de 20 vacas al biodigestor.

Leachate from a composting plant was characterized and applied as a biofertilizer in lettuce crops. Characteristics of untreated (UE) and anaerobically treated (TE) leachate samples were compared. The pH of TE (8.2) increased in relation to the UE (5.2) due to an increase in ammonia nitrogen in TE (1197 mg L-1) compared to UE (859 mg L-1). Anaerobic treatment was efficient in the removal of organic matter from the leachate, evaluated by the decrease of dissolved organic carbon, biochemical oxygen demand, total organic carbon and total solids. K presented the highest concentration (1743 mg L-1) in TE, followed by Mg (135 mg L-1). Cd, Pb and Cr were present at low concentrations in the samples, 0.047, 0.206 and 0.081 mg L-1, respectively. Salmonella, thermotolerant coliforms and viable helminth eggs were not present in TE, which was applied as a biofertilizer in a lettuce crop and compared to mineral fertilization based on fresh matter and dry matter production. Lettuce production using TE was statistically equivalent to mineral fertilization. Toxic metals were not detected in the lettuce shoots. It was concluded that the anaerobically treated leachate from the composting company has the potential to be used as a biofertilizer. crops (UE (TE 8.2 82 8 2 (8.2 5.2 52 5 (5.2 1197 (119 L1 L 1 L-1 859 (85 L1. . demand solids 1743 (174 135 (13 Cd 0047 0 047 0.047 0206 206 0.20 0081 081 0.08 L1, 1, respectively Salmonella shoots 8. (8. 5. (5. 119 (11 L- 85 (8 174 (17 13 (1 004 04 0.04 020 20 0.2 008 08 0.0 (5 11 ( 17 00 02 0.

ABSTRACT The present work aimed to evaluate the production of sulfide through the application of different hydraulic retention times (HRT) and different sulfate loading rates in an up-flow anaerobic sludge blanket (UASB) reactor utilizing acetate-butyrate as electron donors and the coupling of the reactor to a crystallizer to remove metals. The sulfidogenic sludge for the UASB was generated from hydrothermal vent sediments and this was operated at room temperature (18-22 ºC). The sulfate reduction process was linked to the precipitation of Cu2+, Zn2+ and Al3+ in a crystallizer coupled to the UASB reactor (two-stage system) to avoid the toxicity of the metals to the sludge. The concentration of dissolved sulfide increased with the HRT up to 312.9 mg HS-/L at 3 d of HRT. As the sulfate loading rate was increasing, the maximum sulfide concentration obtained was of 376.8 mg HS-/L at 500 mg SO4 -2/L/d (1500 mg/L), whereas the concentration of Cu2+, Zn2+ and Al3+ was up to 150, 100, and 100 mg/L, respectively. The removal efficiencies of Cu2+, Zn2+, and Al3+ were higher than 98% when they were fed separately. When a mixture of metals was added, the removal efficiency was close to 80%. Recovery of metals was lower than 57% in all cases. The sulfide production was supported with acetate-butyrate, being the former commonly accumulated because of the oxidation of higher organic compounds; in this case, its utilization sustained sulfate reduction. This process could be controlled by parameters such as HRT and sulfate loading rate to improve the performance of the bioreactor in the treatment of the effluents contaminated with metals in a two-stage system.

RESUMEN El objetivo del presente trabajo fue evaluar la producción de sulfuro mediante la aplicación de diferentes tiempos de retención hidráulica (TRH) y diferentes cargas de sulfato en un reactor de lecho de lodos de flujo ascendente (UASB, por su sigla en inglés) y estudiar su posible aplicación en la precipitación de Cu2+, Zn2+ y Al3+ en un cristalizador acoplado al reactor UASB (proceso de dos etapas). La concentración de sulfuro disuelto aumentó hasta 312.9 mg HS-/L al aumentar el TRH a 3 d. Al aumentar la carga de sulfato, la concentración máxima de sulfuro que se obtuvo fue de 376.8 mg HS-/L a una carga de 500 mg SO4 -2/L/d (1500 mg/L), mientras que la concentración de Cu2+, Zn2+ y Al3+ fue de hasta 150, 100 y 100 mg/L, respectivamente. Las eficiencias de remoción de Cu2+, Zn2+ y Al3+ fueron mayores a 98 % cuando se alimentaron de forma separada. Cuando se alimentó una mezcla de estos elementos, las eficiencias de remoción fueron cercanas al 80 %. La recuperación de todos los metales fue de 57 % en los tres casos. La producción de sulfuro puede ser controlada por parámetros como el TRH y la carga de sulfato para mejorar el desempeño del reactor en el tratamiento de efluentes contaminados con metales.

ABSTRACT Fruit and vegetable waste (FVW) are sugar-rich substrates that can result in hydrogen through dark fermentation. The success of dark fermentation depends on changing operation parameters, which vary based on the characteristics of the substrate. This study aimed to determine how FVW from a central horticultural wholesaler should be fermented to produce the maximum amount of hydrogen. The following goals were listed as determining the pre-treatment method (chemical, thermic, and acid) for brewery sludge and evaluating the fermentation of the liquid fraction of FVW in an anaerobic structured bed reactor (AnSTBR). The AnSTBR operation started with sucrose as substrate at a hydraulic retention time (HRT) of 6 h. Then, the sucrose was gradually replaced by FVW at the HRT of 6 h. The FVW was fed as the sole carbon source (5 g COD/L) at HRTs of 6, 12, and 3 h for at least 20 days on each condition. The heat treatment resulted in the highest cumulative hydrogen production and hydrogen production rate (HPR) (90 mL H2 and 6.6 mL H2/h). In the AnSTBR operation, the highest values of HPR were observed at 6 h (2094 L H2/m3 reactor.d). The attempt to decrease the HRT to 3 h caused a reduction in the HPR to 216 L H2/m3 reactor.d. It is highly encouraging the increase of the organic loading rate and the use of co-fermentation, aiming to reduce the size of the reactor and water expended on dilution by increasing substrate concentration in future studies. (FVW sugarrich sugar rich parameters pretreatment pre chemical, chemical (chemical thermic acid AnSTBR. . (AnSTBR) (HRT Then 5 ( COD/L CODL COD 12 2 condition (HPR 90 (9 H 66 6. H2/h. H2h Hh H2/h H2/h) 2094 (209 H2m3 Hm m3 m H2/m reactord reactor.d d reactor.d) 21 cofermentation, cofermentation co fermentation, co-fermentation studies (AnSTBR 1 9 209 (20 H2m (2

ABSTRACT Resíduos de frutas e vegetais (RFV) são substratos ricos em açúcar que podem ser usados para produzir hidrogênio por meio da fermentação escura. O sucesso dessa fermentação depende dos parâmetros de operação, que variam com base nas características do substrato. Este estudo teve como objetivo determinar como os RFV de uma central de abastecimento de hortifrutigrangeiros devem ser fermentados para produzir a quantidade máxima de hidrogênio. Os seguintes objetivos foram listados: determinar o método de pré-tratamento (químico, térmico e ácido) para lodo de cervejaria e avaliar a fermentação da fração líquida dos RFV em reator anaeróbio de leito estruturado (AnSTBR). A operação do AnSTBR começou com sacarose como substrato operado com tempo de detenção hidráulica (TDH) de 6 horas. Em seguida, a sacarose foi gradualmente substituída por RFV usando TDH de 6 horas. O RFV foi usado como a única fonte de carbono (5 g DQO/L) com TDHs de 6, 12 e 3 horas por pelo menos 20 dias em cada condição. O tratamento térmico resultou na maior produção cumulativa de hidrogênio e taxa de produção de hidrogênio (TPH) (90 mL H2 e 6,6 mL H2/h). Na operação do AnSTBR, os maiores valores de TPH foram observados em 6 horas (2.094 L H2/m3 reator.d). A tentativa de reduzir o TDH para 3 horas causou uma redução no TPH para 216 L H2/m3 reator.d. É altamente recomendado o aumento da taxa de carga orgânica volumétrica e o uso de co-fermentação, visando reduzir o tamanho do reator e a água gasta na diluição, aumentando a concentração do substrato em estudos futuros. (RFV escura listados prétratamento pré químico, químico (químico ácido AnSTBR. . (AnSTBR) (TDH seguida 5 ( DQO/L DQOL DQO 1 2 condição (TPH 90 (9 H 66 H2/h. H2h Hh H2/h h H2/h) 2.094 2094 094 (2.09 H2m3 Hm m3 m H2/m reatord reator.d d reator.d) 21 cofermentação, cofermentação co fermentação, co-fermentação diluição futuros (AnSTBR 9 2.09 209 09 (2.0 H2m 2.0 0 (2. 2. (2

ABSTRACT This study assesses the influent and effluent characteristics and the removal efficiency of 56 wastewater treatment plants (WWTPs) operating in Brazil’s southern region, in the Rio Grande do Sul state. The analysis encompasses the main secondary wastewater treatment processes used in the country, such as septic tank and anaerobic filter, activated sludge with sequencing batch reactor and with extended aeration, upflow anaerobic sludge blanket reactor followed by trickling filter, anaerobic and facultative ponds, and the combination of anaerobic, facultative, and maturation ponds. The parameters evaluated were biochemical oxygen demand (BOD), chemical oxygen demand (COD), ammoniacal nitrogen (NNH3), total phosphorus (TP), total suspended solids (TSS), and Escherichia coli. The influent concentrations of BOD, COD, and TSS were considerably lower than other values reported in studies in Brazil, indicating that the analyzed WWTPs operate with a diluted influent, with respective average ranges of 38–189, 203–416, and 75–242 mg∙L−1. The effluent concentrations were also lower than the reference values, although the differences were not as pronounced as in the influent. No significant distinctions were observed between the removal efficiencies obtained and other results in the literature, except for TSS, which had a weaker performance. Concerning the technologies, lower performance was observed for BOD, COD, and TSS removal in the septic tank and higher removal rates of TP for the activated sludge systems. This study represents the first comprehensive dataset on the performance of WWTPs in Brazil’s southern region, contributing to the understanding of wastewater management practices in the country by indicating potential points for improvement. 5 (WWTPs Brazils Brazil s region state filter aeration ponds BOD , (BOD) COD (COD) NNH3, NNH3 NNH (NNH3) TP, (TP) (TSS) coli 38189 38 189 38–189 203416 203 416 203–416 75242 75 242 75–24 mgL1 mgL mg L 1 mg∙L−1 literature technologies systems improvement (BOD (COD (NNH3 (TP (TSS 3818 3 18 38–18 20341 20 41 203–41 7524 7 24 75–2 mg∙L− (NNH 381 38–1 2034 2 4 203–4 752 75– mg∙L 38– 203–

RESUMO O presente estudo caracteriza o afluente, o efluente e a eficiência de remoção de 56 estações de tratamento de esgoto (ETEs) em operação no Rio Grande do Sul, Brasil. A análise abrange os principais processos de tratamento de esgoto utilizados no país: fossa séptica e filtro anaeróbio, lodo ativado com reator sequencial em batelada e com aeração estendida, reator UASB e filtro biológico, lagoas anaeróbias e facultativas, e a combinação de lagoas anaeróbias, facultativas e de maturação. Os parâmetros avaliados foram demanda bioquímica de oxigênio (DBO), demanda química de oxigênio (DQO), nitrogênio amoniacal (NNH3), fósforo, sólidos suspensos totais (SST) e Escherichia coli. As concentrações afluentes de DBO, DQO e SST (intervalos médios respectivos de 38–189, 203–416 e 75–242 mg∙L−1) foram inferiores às reportadas em outros estudos no Brasil, indicando que as ETEs analisadas operam com um afluente mais diluído. O efluente também apresentou concentrações abaixo dos valores de referência, embora essas diferenças não tenham sido tão acentuadas quanto no afluente. Em geral, não foram observadas discrepâncias significativas entre as eficiências de remoção obtidas e outras estimativas da literatura, exceto para SST, com valores inferiores de remoção. Fossas sépticas obtiveram menor eficiência na remoção de DBO, DQO e SST, enquanto sistemas de lodo ativado foram melhores na remoção de fósforo. Este estudo representa o primeiro conjunto de dados abrangente sobre o desempenho de ETEs na região Sul do Brasil, identificando áreas potenciais para aprimoramento e contribuindo para uma melhor gestão desses sistemas. 5 (ETEs Brasil país anaeróbio estendida biológico maturação DBO , (DBO) DQO, (DQO) NNH3, NNH3 NNH (NNH3) fósforo (SST coli intervalos 38189 38 189 38–189 203416 203 416 203–41 75242 75 242 75–24 mg∙L−1 mgL1 mgL mg L 1 diluído referência geral literatura (DBO (DQO (NNH3 3818 3 18 38–18 20341 20 41 203–4 7524 7 24 75–2 mg∙L− (NNH 381 38–1 2034 2 4 203– 752 75– mg∙L 38–

Abstract Biogas production through co-digestion of two or more waste products has garnered increasing attention from researchers seeking to optimize this process. Biogas and methane production increase with the addition of glycerol to agro-industrial wastes during anaerobic biodigestion. However, the utilization of a two-phase process focused on hydrogen production has not been widely explored. This work aims to evaluate two-phase anaerobic biodigestion of cassava wastewater by adding residual glycerol and swine wastewater to enhance hydrogen and methane production. A pilot-scale biodigester was used during the acidogenic phase at 38.5°C, containing 4% glycerol. The effluent was submitted to methanogenic treatment, and the influence of temperature (36.0 to 39.0°C) and sodium bicarbonate concentration (2.0 to 6.0 g L-1) were evaluated. The results indicated that the optimum conditions during the methanogenic phase were 39.0°C with a sodium bicarbonate concentration of 5.0 g L-1. The two-phase biodigestion produced 30.8 mL of (H2) RCOD-1 and 104.5 mL of (CH4) RCOD-1. Thus, the substrates and inoculum used were adequate for the anaerobic biodigestion process, increasing the energetic efficiency of the process due to hydrogen production. codigestion co digestion agroindustrial agro industrial However twophase explored pilotscale pilot scale 385C C 38 5 38.5°C 4 treatment 36.0 360 36 0 (36. 390C 39 2.0 20 2 (2. 60 6 6. L1 L 1 L-1 evaluated 50 5. L1. 1. 308 30 8 30. H2 H (H2 RCOD1 RCOD RCOD- 1045 104 104. CH4 CH (CH4 RCOD1. Thus 3 36. (36 2. (2 L- (H 10 (CH (3 (

RESUMO A produção de biogás por meio da codigestão de dois ou mais resíduos tem atraído atenção crescente de pesquisadores que buscam otimizar esse processo. A adição de glicerol aos resíduos agroindustriais durante a biodigestão anaeróbica tem demonstrado aumentar a produção de biogás e metano. No entanto, a utilização de um processo em duas fases focado na produção de hidrogênio ainda não foi amplamente explorada. Este trabalho visa avaliar a biodigestão anaeróbica em duas fases de águas residuais de mandioca, adicionando glicerol residual e águas residuais suínas para aumentar a produção de hidrogênio e metano. Um biodigestor em escala piloto foi utilizado durante a fase acidogênica a 38,5°C, contendo 4% de glicerol. O efluente foi submetido a tratamento metanogênico, e a influência da temperatura (36,0 a 39,0°C) e da concentração de bicarbonato de sódio (2,0 a 6,0 g L⁻¹) foi avaliada. Os resultados indicaram que as condições ótimas durante a fase metanogênica foram 39,0°C com uma concentração de bicarbonato de sódio de 5,0 g L⁻¹. A biodigestão em duas fases produziu 30,8 mL de H₂ por RCOD⁻¹ e 104,5 mL de CH₄ por RCOD⁻¹. Assim, os substratos e o inóculo utilizados foram adequados para o processo de biodigestão anaeróbica, aumentando a eficiência energética do processo devido à produção de hidrogênio. metano entanto explorada mandioca 385C C 38 5 38,5°C 4 metanogênico 36,0 360 36 0 (36, 390C 39 2,0 20 2 (2, 60 6 6, L⁻¹ L¹ L ¹ avaliada 50 5, 308 30 8 30, H RCOD¹ RCOD RCOD⁻ 1045 104 104, CH Assim 3 36, (36 2, (2 L⁻ 10 (3 ( 1

Abstract The growing sector of dairy industry in Bulgaria leads to large waste stream formation with high pollution variation, which require specific treatment application. In the present research different fractions and wash waters from the production of kashkaval and white brined cheese, milk curd, strained yoghurt manufactured in three medium-type Bulgarian milk processing plants were studied. The basic indicators for wastewater quality: total solids (TS), total suspended solids (TSS), active reaction, fat, oil and grease (FOG), 5-day biological oxygen demand (BOD5), chemical oxygen demand (COD), total nitrogen (TN) and total phosphorus (TP) were analysed by standard procedures. The obtained results indicate that kashkaval whey from the sheep’s milk processing was the most contaminated effluent, reaching COD more than 68,000 mg O2/dm3 and BOD5 - up to 37,000 mg O2/dm3. Such high concentrated wastewaters can be treated only by anaerobic methods. Secondary cheese whey (SCW) has less impurities than cheese whey, but its soluble milk fractions are difficult to biodegrade, resulting in BOD5:COD ratio lower than 0.40. Application of membrane technologies in milk co-product processing remove totally FOG from the SCW, where BOD5 and COD values are around 950 and 2.500 mg O2/dm3, respectively. However, the TN concentration in it is not enough to apply directly aerobic utilization. This method is the most appropriate for washing waters, which occupy both the largest volume and the cleanest fractions of all milk effluents. Future combinations of different dairy wastewaters will show the best utilization protocol for each of the milk processing plant. variation application curd mediumtype medium type studied quality TS, TS , (TS) TSS, TSS (TSS) reaction fat FOG, (FOG) 5day day 5 BOD5, BOD (BOD5) COD, (COD) (TN TP (TP procedures sheeps sheep s effluent 68000 68 000 68,00 O2dm3 Odm O2 dm3 O dm O2/dm 37000 37 37,00 methods SCW (SCW biodegrade BOD5COD BODCOD 040 0 40 0.40 coproduct co product 95 2500 2 500 2.50 respectively However effluents plant (TS (TSS (FOG (BOD5 (COD 6800 6 00 68,0 O2dm 3700 3 37,0 04 4 0.4 9 250 50 2.5 (BOD 680 68, 370 37, 0. 25 2.

RESUMO O gerenciamento de resíduos sólidos municipais representa um desafio significativo para o futuro da sociedade. As tecnologias de compostagem e digestão anaeróbica processam resíduos orgânicos, fornecendo material e recuperação de energia, respectivamente. Este estudo avaliou os locais mais adequados para a instalação de estações de tratamento da fração orgânica dos resíduos sólidos urbanos em duas cidades brasileiras, João Pessoa (PB) e Florianópolis (SC), considerando critérios ambientais, sociais e geográficos. Além disso, foram discutidas as principais legislações sobre o gerenciamento de resíduos orgânicos nessas cidades, destacando os avanços em relação às normas nacionais. Em Florianópolis, as áreas adequadas representam 0,5% da área total, totalizando 3,10 km2. Em João Pessoa, a área final adequada abrange 16,76 km2, ou 8% do território. Os aspectos ambientais e as áreas residenciais foram identificados como os critérios restritivos mais relevantes para a seleção de locais adequados. Em termos de políticas públicas existentes, Florianópolis destaca-se em termos de gestão de resíduos orgânicos, com regras mais claras e eficazes, enquanto João Pessoa ainda precisa de uma política mais consistente e integrada. sociedade energia respectivamente brasileiras PB (PB SC, SC , (SC) geográficos disso nacionais 05 0 5 0,5 total 310 3 10 3,1 km2 km 1676 16 76 16,7 8 território existentes destacase destaca se eficazes integrada (SC 0, 31 1 3, 167 7 16,

Abstract The management of municipal solid waste represents a significant challenge for the future of society. The technologies of composting and anaerobic digestion process organic waste, providing material, and energy recovery, respectively. This study evaluated the most suitable locations for installing treatment plants for the organic fraction of municipal solid waste in two Brazilian cities, João Pessoa and Florianópolis, considering environmental, social, and geographical criteria. Furthermore, the main legislation on organic waste management in these cities was discussed, highlighting advances in relation to national regulations. In Florianópolis, the suitable areas represent 0.5% of the total area, totaling 3.10 km2. In João Pessoa, the final suitable area covers 16.76 km2 or 8% of the territory. Environmental aspects and residential areas were identified as the most relevant restrictive criteria for selecting suitable sites. In terms of existing public policies, Florianópolis stands out in terms of organic waste management, with clearer and more effective rules, while João Pessoa still needs a more consistent and integrated policy. society material recovery respectively environmental social Furthermore discussed regulations 05 0 5 0.5 310 3 10 3.1 km 1676 16 76 16.7 8 territory sites policies rules policy 0. 31 1 3. 167 7 16.

At sewage treatment plants, sludge management remains a bottleneck, requiring efficient and cost-effective solutions for treating this solid byproduct. It is known that the presence of plants can accelerate the sludge drying process, as a result, vertically flowed constructed wetlands (VFCWs) have been evaluated as alternatives to traditional drying beds. Though, for better applicability of this technology, this study premised on evaluating greenhouse gas (GHG) emissions in VFCWs constructed for anaerobic sludge treatment. To compare GHG emissions across different seasonal conditions, three configurations were tested: four units planted with Tifton-85 grass (Cynodon spp.), four units planted with elephant grass (Cenchrus purpureus), four control units without vegetation presence, with four sludge loading rates in each configuration: 75, 100, 150, and 200 kg TS (total solids) m-2 year-1. Higher sludge loading rates led to increased methane emissions, with emissions escalating during the rainy season. Methane emissions decreased towards the end of the resting period. The presence of vegetation reduced methane emissions mainly during the resting period due to increased aeration of the units. The conditions that would provide lower GHG emissions would be with loads of up to 100 kg m-2 year-1, in units planted with Tifton grass. bottleneck costeffective cost effective byproduct process result (VFCWs beds Though technology (GHG tested Tifton85 85 Tifton-8 Cynodon spp., spp spp. , spp.) Cenchrus purpureus, purpureus purpureus) configuration 75 150 20 total solids m2 m 2 m- year1. year1 year 1. 1 year-1 season 10 year1, 1, Tifton8 8 Tifton- 7 15 year-

Abstract Tetanus is an infectious disease caused by a ubiqui tous bacterium Clostridium tetani, that synthesizes and releasesa potent neurotoxin under anaerobic conditions, which is responsible for the clinical manifestations. As it is found in soil contaminated with animal and human excreta, it is difficult to eradicate but it may be prevented by immunization. Immunization rate has decreased in the last years, especially during the COVID-19 pandemic. We report two cases of tetanus, attended during 2022. A 39-year-old man whose entry route was a gunshot wound and he was discharged from the intensive care unit (ICU) and a second case of an 83-year-old woman with unknown entry point, who died during her ICU stay. The cases reported highlight that it is a life-threatening disease, its diagnosis is mainly clinical and it should be in the algorithm of differential diagnoses. We emphasize about the prompt treatment administration or consulta tion to a specialized healthcare center. The importance of this presentation is to show the severity of the dis ease, whose assessment is mainly clinical and should not escape the algorithm of differential diagnoses, em phasizing that treatment should be instituted early or when in doubt consult a specialized center. In addition to this, it is important to check theimmunization rate in our country, especially during thepandemic, becauseit is a vaccine-pre ventable disease.

Resumen El tétanos es causado por el Clostridium tetani, una bacteria ubicua que frente a condiciones de anaerobio sis puede sintetizar y liberar sus toxinas, responsables del cuadro clínico. Dado que es una bacteria que se encuentra en el suelo y en el tracto gastrointestinal de muchas especies, se trata de una enfermedad no erra dicable pero si controlable a través de la inmunización para la prevención. Las tasas de inmunización han disminuido en los últimos años, evento que se ha acentuado durante la COVID-19. Se presentan a continuación dos casos clínicos in gresados durante el año 2022. El primero es un hombre de 39 años cuya puerta de entrada fue una herida de arma de fuego conevolución favorable y el segundo caso se trata de una mujer de 83 años sin puerta de entrada clara quien falleció durante su internación en terapia intensiva. La importancia de esta presentación es mos trar la gravedad de la enfermedad, cuyavaloración es principalmente clínica y no debe escapar al algoritmo de diagnósticos diferenciales, acentuando que se debe instaurar el tratamiento de forma precoz o frente a la duda consultar con un centro especializado. Asímismo, es importante revisar las tasas de inmuni zación en nuestro país y los cambios que se presentaron durante la pandemia, teniendo en cuenta, como se ha expuesto previamente, se trata de una enfermedad in munoprevenible.