Luiz Olinto Monteggia

A full-scale UASB reactor for treatment of pig and cattle slaughterhouse wastewater with a high oil and grease content

This paper discusses the performance of an 800m3 full-scale UASB reactor in treating meat-packing plant and slaughterhouse effluents containing high concentrations of oil and grease (O&G) (413-645 mg/L), resulting in a COD/O&G ratio of 26-32%. Those macromolecules were considered responsible for the unbalance of the system resulting in a total washout of the biomass. The removal of O&G from the influent using a physicochemical system (coagulation-flocculation) improved the physical characteristics of the anaerobic sludge, controlling the biomass washout. Reactor performance was significantly improved when the COD/O&G ratio influent was maintained in the 10%. The COD and O&G removal rates obtained after implantation of the physicochemical system were 70-92% and 27-58%, respectively. The specific methanogenic activity (SMA) of the biomass shows towards a tendency stabilisation and adaptation to the substrate influent. Pretreatment of the influent allowed the maximum organic load to be increased (1.46 to 2.43 Kg COD/m3.d) and improved the quality of the effluent.

Pyrolysis of algal biomass obtained from high-rate algae ponds applied to wastewater treatment

This work presents the results of the pyrolysis of algal biomass obtained from high rate algae ponds treating sewage. The two high-rate algae ponds (HRAP) were built and operated at the Sao Joao Navegantes Wastewater Treatment Plant. The HRAP A was fed with raw sewage while the HRAP B was fed with effluent from an Upflow Anaerobic Sludge Blanket (UASB) reactor. The HRAP B provided higher productivity, presenting total solids concentration of 487.3mg/l and chlorophyll a of 7735mg/l. The algal productivity in the average depth was measured at 41,8 gm-2day-1 in pond A and at 47.1 gm-2day-1 in pond B. Algae obtained from the HRAP B were separated by the process of coagulation/flocculation and sedimentation. In the presence of alum, a separation efficiency in the range of 97% solids removal was obtained. After centrifugation the biomass was dried and comminuted. The biofuel production experiments were conducted via pyrolysis in a tubular quartz glass reactor which was inserted in a furnace for external heating. The tests were carried out in an inert nitrogen atmosphere at a flow rate of 60ml/min. The system was operated at 400°C, 500°C and 600°C in order to determine the influence of temperature on the obtained fractional yields. The studies showed that the pyrolysis product yield was influenced by temperature, with a maximum liquid phase (bio-oil and water) production rate of 44% at 500°C, 45% for char and around 11% for gas.

Avaliação da viabilidade de utilização de colifagos como indicadores de poluição fecal: suas relações com parâmetros físicos e químicos e indicadores bacterianos

Coliform bacteria, currently used as fecal indicator, does not ensure the absence of other pathogenic microorganisms in water, mainly enteric viruses. The objective of this study was to evaluate the viability of using coliphages as viral indicators in the effluent from Wastewater Treatment Plants (WWTP) due to the fact that Coliphages determination involves a simplified methodology. The seasonal pattern of coliphages was measured in the final effluent of a domestic WWTP, which occurred in higher values, mainly during dry seasons periods. This behavior was similar with the described by the authors in relation to enteric viruses in water. Significant relationship was not found among coliphages and coliforms, as well as with the physical and chemical parameters analyzed. The need for joint monitoring of viruses and bacteria is emphasized, in order to ensure the proper quality of treated water.