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Four goats were inoculated with an inactivated peste des petits ruminants virus ( PPRV) vaccine. Three unvaccinated goats were kept as controls. After 36 days, the four goats were revaccinated. The immune response was monitored by virus neutralization test showing that two doses of the vaccine were able to stimulate strong immune response in all the vaccinated animals. The vaccinated goat and the controls were challenged with virulent PPRV intranasally. After PPRV challenge, the three control goats showed fever, viremia and virus excretion through mucosal surfaces, whereas the vaccinated goats were fully protected against PPRV infection and replication. [ABSTRACT FROM AUTHOR]

Discusses the implementation, study and calibration of a modified Activated Sludge Model n. 2d (ASM2d) for the simulation of the sequencing batch reactor process. Division of the nitrification stage in a two-step process; Implementation of the model through a technique allowing complied C++ modules to be linked to an ordinary Simulink block diagram.

Research activities carried out at ENEA during the last few years allowed the development of a Sequencing Batch Reactor (SBR) that is able to remove biologically organic waste, nitrogen and phosphorus and that was shown to be particularly suited to obtaining low effluent nutrient concentrations even starting from concentrated wastes. Researchon optimisation of time cycles and on process modelling, allowed an advanced comprehension of reactor behaviour and the development of a process able to obtain more than 98% removal of nitrogen, phosphorus and COD, and therefore almost capable of matching effluent standards with a sole biological process. On the basis of laboratory results and process modelling, a full scale SBR plant has been designed and realised. This plant, in ten months of operation, is achieving even better results compared to the laboratory ones. (C) 1999 IAWQ Published by Elsevier Science. All rights reserved. [ABSTRACT FROM AUTHOR]

Activated sludge from a new activated sludge modification for biological phosphorus and nitrogen removal was studied. Population dynamicsand the phenomenon of anoxic phosphate uptake with simultaneous denitrification were investigated. The ability of the process to remove nutrients and to suppress filamentous bulking was studied. The course of phosphate concentrations along the tested system showed an anoxic phosphate uptake with simultaneous denitrification, The mechanism of anoxic phosphate uptake was confirmed using kinetic batch tests. ) 1998 IAWQ. Published by Elsevier Science Ltd. [ABSTRACT FROM AUTHOR]

An intrinsic characteristic of the Italian industrial production system is the presence of several industrial districts with a prevalent manufacturing typology, in which several small and medium enterprisesdealing with the same or similar products are concentrated in a small territory. An important textile district is localized in Como area,north of Italy. In many cases, industrial districts are served by large treatment plants that receive the majority of the pollution loading from several small and medium enterprises that do not have internal treatment facilities. The treatment fee is determined by regional regulations; commonly, the single wastewater stream connected to the sewer is billed by the sewer manager to the source industry on the basis of the flow rate and of a complex formula that takes into account a series of parameters. This method is unable to properly evaluate the relationship between treatment fee and actual treatment costs, since conventional physical-chemical and biochemical parameters are not necessarily linked to wastewater treatability. New advanced respirometric methodologies could be used as wastewater characterization techniques, since they are particularly suited to represent the effect of agiven wastewater on the final wastewater treatment plant. Hence, they could be better correlated to treatment costs. The instrument developed is composed of two parallel moving bed continuous flow completely mixed reactors of the working volume of about 5 l each, equipped with oxygen sensors connected to a computer that acts as a controller and as a data acquisition and processing unit. Some examples of experimental results obtained with synthetic waste and with real sewage arepresented. [ABSTRACT FROM AUTHOR]

The phenomenon of anoxic phosphate uptake with simultaneous denitrification was studied. For this purpose kinetic batch tests have been carried out by using the activated sludge samples from three modifications of nutrient removal activated sludge systems: two based on an anaerobic-anoxic-oxic (A2/O) system and a third on an anaerobic-oxic (A/O) system. The results showed significant differences in anoxic phosphate uptake rate between activated sludge which was alternatively exposed to anoxic conditions and activated sludge from the A/O arrangement. These differences were also accompanied by different denitrification rates. Simultaneously with batch experiments the microscopic observation of activated sludge samples was carried out. Neisser and Gram stained samples showed clear differences in shape, size and distribution of polyphosphate accumulating bacteria between A2/O and A/O processes. Moreover, experiments performed using genetic probes confirmed the differences in microbiological composition of activated sludge samples from different nutrient removal system arrangements. [ABSTRACT FROM AUTHOR]

The development and the sensitivity analysis of a dynamic SBR simulation model for biological nitrogen removal, based on the Activated Sludge Model N. 1, are Presented. Am experimental study for the calibration and validation of the model was carried out using a bench scale SBR. Piggery wastewater was used as feed. The operating daily cycle of the SBR reactor included three sub-cycles of 7.5 hours each, each one alternating anoxic and anaerobic condition, while settling phase was carried out at the end of the three sub-cycles. A first enhancement of model N. 1 was performed splitting nitrification into two sub-processes of nitritation and nitratation. A second enhancement of the model as obtained with the introduction of a switch function of nitratation kinetics. gth and phase distribution An algorithm for optimization of the cycle length and phase distribution in order to minimize effluent concentration was developed. A design procedure of SBR systems is also described. [ABSTRACT FROM AUTHOR]