Enhancing the production of volatile fatty acids by potassium permanganate from wasted sewage sludge: A batch test experiment

Recovering resources from wastewater treatment is vital for the transition from a linear to a circular economy model in the water sector. Volatile Fatty Acids (VFAs) are valuable products among the possible recovered resources. This study investigates the influence of potassium permanganate (KMnO4) addition during acidogenic fermentation of waste activated sludge for enhancing VFAs production. Specifically, different fermentation batch tests with and without KMnO4 addition were carried out using two distinctive sewage sludges as feedstocks. Results showed that KMnO4 addition increased the VFAs yield up to 144 and 196 mgCOD/g VSS for the two sludges. When KMnO4 was used as pre-treatment, 55 % of sCOD were VFAs. This latter result was mainly debited to the recalcitrant organics’ disruption promoted by the oxidative permanganate ability

Volatile fatty acids from sewage sludge by anaerobic membrane bioreactors: Lesson learned from two-year experiments with fouling analysis by the resistance in series model

Volatile fatty acid (VFA) production from sewage sludge has become one of the main biotechnologies implemented in view of the circular economy application in wastewater treatment plant (WWTP) management. In this study, domestic sewage sludge collected from three WWTPs over two-year experiments was subjected to acidogenic fermentation. The fermented liquid was recovered through an ultrafiltration membrane. The membrane fouling was analysed in detail by applying the resistance in series model, revealing the major role of the extra polymeric substances in the reversible fouling, accounting for 91.2 % of the total resistance. Finally, the major contribution of the carbon footprint assessment was due to the indirect emissions (1.30 kg CO2eq/m3). The study has the novelty of providing an in-depth understanding of MBR membrane fouling used for solid/liquid separation in a plant aimed at VFA recovery from sewage sludge acidogenic fermentation. Also, the carbon footprint assessment provides insights regarding the environmental impact of VFA recovery through ultrafiltration membrane

As contribuições da noção de ambivalência em Bauman para uma interpretação do esporte na escola

Dissertação (mestrado)—Universidade de Brasília, Faculdade de Educação Física, Programa de pós-graduação em Educação Física, Mestrado em Educação Física, 2012.O presente estudo teve por objetivo discutir o esporte na escola para além de uma dicotomia recorrente nos debates, entre o caráter formativo e o caráter alienador. Foi motivado pelas contribuições teóricas de Bauman, que oportunizaram uma compreensão mais abrangente do esporte. Nessa ótica, apontou-se como hipótese a possibilidade de explicar o esporte na escola como um fenômeno ambivalente; mas, não dicotômico. A partir do uso da técnica de grupos focais, os resultados obtidos evidenciaram que o esporte incorpora um dualismo, em razão da dificuldade de conceituá-lo, de precisar seus objetivos e da diversidade de utilização do termo “esporte” nos debates sobre o tema, especialmente, no contexto da prática da Educação Física na escola. ______________________________________________________________________________ ABSTRACTThis study aimed at discussing sports in school beyond the recurring dichotomy in discussions between the formative and alienating character. It was motivated by the theoretical contributions of Bauman, which allowed a more comprehensive understanding of the sport. From this perspective, it was pointed out as a hypothesis to explain the possibility of sports in school as an ambivalent phenomenon, but not dichotomous. From the use of the technique of focus groups, the results showed that sports embody a dualism because of the difficulty in classifying them, clarifying their goals and because of the diversity of use of the term "sport" in the debates on the subject, especially in the context of the practice of physical education at school

Reduction of sewage sludge and N2O emissions by an Oxic Settling Anaerobic (OSA) process: The case study of Corleone (Italy) wastewater treatment plant

Biosolid management is becoming one of the most crucial issues for wastewater treatment plant (WWTP) op-erators. The application of the Oxic Settling Anaerobic (OSA) process allows the minimisation of excess sludge production. This study compares conventional activated sludge (CAS) and OSA layouts in a full-scale WWTP (namely, Corleone -Italy). Extensive monitoring campaigns were conducted to assess treatment performances regarding carbon and nutrient removal, greenhouse gas (GHG) emissions, excess sludge production, and biomass activity (by means of respirometric analysis). Results showed that the effluent quality consistently met the Italian discharge limits. However, with the implementation of the OSA process, there was a decrease in ammonium removal efficiency, which could be attributed to reduced nitrifier activity related to reduced biomass production and extended anaerobic conditions affecting the nitrification process. On the other hand, the OSA configuration significantly increased phosphorus removal, indicating a high phosphorus content in the resulting waste sludge. A worsening of the sludge settling properties was observed with the OSA configuration likely due to decreased EPS concentrations. The sludge production in the OSA configuration decreased by 17.3 % compared to CAS. Nitrous-oxide measurements did not show a variation between CAS and OSA configurations, confirming that the OSA process can be a suitable solution for reducing WWTP's carbon footprint

Initial pH Conditions Shape the Microbial Community Structure of Sewage Sludge in Batch Fermentations for the Improvement of Volatile Fatty Acid Production

Conversion of wastewater treatment plants into biorefineries is a sustainable alternative for obtaining valuable compounds, thus reducing pollutants and costs and protecting the environment and human health. Under specific operating conditions, microbial fermentative products of sewage sludge are volatile fatty acids (VFA) that can be precursors of polyhydroxyalkanoate thermoplastic polyesters. The role of various operating parameters in VFA production has yet to be elucidated. This study aimed to correlate the levels of VFA yields with prokaryotic microbiota structures of sewage sludge in two sets of batch fermentations with an initial pH of 8 and 10. The sewage sludge used to inoculate the batch fermentations was collected from a Sicilian WWTP located in Marineo (Italy) as a case study. Gas chromatography analysis revealed that initial pH 10 stimulated chemical oxygen demands (sCOD) and VFA yields (2020 mg COD/L) in comparison with initial pH 8. Characterization of the sewage sludge prokaryotic community structures-analyzed by next-generation sequencing of 16S rRNA gene amplicons-demonstrated that the improved yield of VFA paralleled the increased abundance of fermenting bacteria belonging to Proteobacteria, Bacteroidetes, Chloroflexi, and Firmicutes phyla and, conversely, the reduced abundance of VFA-degrading strains, such as archaeal methanogens

Circumferential dissection of deep fascia as ancillary technique in circumcision: is it possible to correct phimosis increasing penis size?

Background: Phimosis is the inability to retract the preputium downward over the glans penis. Despite the various techniques of preputial plasty described in literature, the most performed surgical treatment is still the conventional circumcision.Methods: In this paper we retrospectively reviewed data of a homogeneous population of 36 consecutive adult patients who underwent phimosis correction by circumcsion with dissection of the Deep Fascia. Patients were followed up by one independent plastic surgeon that measured penis length and circumference in nonerected state preoperatively and at 6 month time postoperatively.Results: The Wilcoxon Signed Rank Test showed a significant (p < 0.0001) difference between the two groups both in terms of length and circumference.Conclusions: In conclusion, the ancillary technique we described leads to an increase of penis size, is safe and easy to perform and does not increase significantly operative time nor complication rate to the conventional procedure

The Potential Immunonutritional Role of Parmigiano Reggiano Cheese in Children with Food Allergy

Parmigiano Reggiano (PR) is a ripened cheese with high nutritional value. Throughout ripening the bacteria contained in PR promote an extensive hydrolysis of cow’s milk proteins resulting in peptides that exhibit positive immunoregulatory activities. Additional modulatory activities on immune system are induced by butyrate, a short chain fatty acid widely expressed in PR. These findings suggest a possible immunonutritional role for PR able to stimulate oral tolerance in children with food allergy (FA)