Start-up of two moving bed membrane bioreactors treating saline wastewater contaminated by hydrocarbons.

This work aims to assess the acclimation of microorganisms to a gradual increase of salinity and hydrocarbons, during the start-up of two moving bed membrane bioreactors (MB-MBRs) fed with saline oily wastewater. In both systems an ultrafiltration membrane was used and two types of carriers were employed: polyurethane sponge cubes (MB-MBRI) and polyethylene cylindrical carriers (MB-MBRII). A decreasing dilution factor of slops has been adopted in order to allow biomass acclimation. The simultaneous effect of salinity and hydrocarbons played an inhibitory role in biomass growth and this resulted in a decrease of the biological removal efficiencies. A reduction of bound extracellular polymeric substances and a simultaneous release of soluble microbial products (SMPs) were observed, particularly in the MB-MBRII system, probably due to the occurrence of a greater suspended biomass stress as response to the recalcitrance of substrate. On the one hand, a clear attachment of biomass occurred only in MB-MBRI and this affected the fouling deposition on the membrane surface. The processes of detachment and entrapment of biomass, from and into the carriers, significantly influenced the superficial cake deposition and its reversibility. On the other hand, in MB-MBRII, the higher production of SMPs implied a predominance of the pore blocking.

Bayesian inference analysis of the uncertainty linked to the evaluation of potential flood damage in urban areas.

Flood damage in urbanized watersheds may be assessed by combining the flood depth-damage curves and the outputs of urban flood models. The complexity of the physical processes that must be simulated and the limited amount of data available for model calibration may lead to high uncertainty in the model results and consequently in damage estimation. Moreover depth-damage functions are usually affected by significant uncertainty related to the collected data and to the simplified structure of the regression law that is used. The present paper carries out the analysis of the uncertainty connected to the flood damage estimate obtained combining the use of hydraulic models and depth-damage curves. A Bayesian inference analysis was proposed along with a probabilistic approach for the parameters estimating. The analysis demonstrated that the Bayesian approach is very effective considering that the available databases are usually short.

Uncertainty evaluation of design rainfall for urban flood risk analysis.

A reliable and long dataset describing urban flood locations, volumes and depths would be an ideal prerequisite for assessing flood frequency distributions. However, data are often piecemeal and long-term hydraulic modelling is often adopted to estimate floods from historical rainfall series. Long-term modelling approaches are time- and resource-consuming, and synthetically designed rainfalls are often used to estimate flood frequencies. The present paper aims to assess the uncertainty of such an approach and for suggesting improvements in the definition of synthetic rainfall data for flooding frequency analysis. According to this aim, a multivariate statistical analysis based on a copula method was applied to rainfall features (total depth, duration and maximum intensity) to generate synthetic rainfalls that are more consistent with historical events. The procedure was applied to a real case study, and the results were compared with those obtained by simulating other typical synthetic rainfall events linked to intensity-duration-frequency (IDF) curves. The copula-based multi-variate analysis is more robust and adapts well to experimental flood locations even if it is more complex and time-consuming. This study demonstrates that statistical correlations amongst rainfall frequency, duration, volume and peak intensity can partially explain the weak reliability of flood-frequency analyses based on synthetic rainfall events.

Uncertainty in urban flood damage assessment due to urban drainage modelling and depth-damage curve estimation.

Due to the increased occurrence of flooding events in urban areas, many procedures for flood damage quantification have been defined in recent decades. The lack of large databases in most cases is overcome by combining the output of urban drainage models and damage curves linking flooding to expected damage. The application of advanced hydraulic models as diagnostic, design and decision-making support tools has become a standard practice in hydraulic research and application. Flooding damage functions are usually evaluated by a priori estimation of potential damage (based on the value of exposed goods) or by interpolating real damage data (recorded during historical flooding events). Hydraulic models have undergone continuous advancements, pushed forward by increasing computer capacity. The details of the flooding propagation process on the surface and the details of the interconnections between underground and surface drainage systems have been studied extensively in recent years, resulting in progressively more reliable models. The same level of was advancement has not been reached with regard to damage curves, for which improvements are highly connected to data availability; this remains the main bottleneck in the expected flooding damage estimation. Such functions are usually affected by significant uncertainty intrinsically related to the collected data and to the simplified structure of the adopted functional relationships. The present paper aimed to evaluate this uncertainty by comparing the intrinsic uncertainty connected to the construction of the damage-depth function to the hydraulic model uncertainty. In this way, the paper sought to evaluate the role of hydraulic model detail level in the wider context of flood damage estimation. This paper demonstrated that the use of detailed hydraulic models might not be justified because of the higher computational cost and the significant uncertainty in damage estimation curves. This uncertainty occurs mainly because a large part of the total uncertainty is dependent on depth-damage curves. Improving the estimation of these curves may provide better results in term of uncertainty reduction than the adoption of detailed hydraulic models.

Evaluation of the apparent losses caused by water meter under-registration in intermittent water supply.

Apparent losses are usually caused by water theft, billing errors, or revenue meter under-registration. While the first two causes are directly related to water utility management and may be reduced by improving company procedures, water meter inaccuracies are considered to be the most significant and hardest to quantify. Water meter errors are amplified in networks subjected to water scarcity, where users adopt private storage tanks to cope with the intermittent water supply. The aim of this paper is to analyse the role of two variables influencing the apparent losses: water meter age and the private storage tank effect on meter performance. The study was carried out in Palermo (Italy). The impact of water meter ageing was evaluated in laboratory by testing 180 revenue meters, ranging from 0 to 45 years in age. The effects of the private water tanks were determined via field monitoring of real users and a mathematical model. This study demonstrates that the impact on apparent losses from the meter starting flow rapidly increases with meter age. Private water tanks, usually fed by a float valve, overstate meter under-registration, producing additional apparent losses between 15% and 40% for the users analysed in this study.

Integrated urban water modelling with uncertainty analysis.

In the last twenty years, the scientific world has paid particular care towards the problems that involve the environment. Accordingly, several researches were developed to describe phenomena that take place during both wet and dry periods and to increase the knowledge in this field. In particular, attention was addressed towards the problems linked with receiving water body pollution because of the impact of rain water in the urban environment. In order to obtain a good description of the problem, it is important to analyse both quantity and quality aspects connected with all the transformation phases that characterise the urban water cycle. Today, according to this point, integrated modelling approach is spreading, aiming to find solutions to improve the quality characteristics of the receiving water body. Because several models are connected together for analysing the fate of pollutants from the sources on the urban catchment to the final recipient, classical problems connected with the selection and calibration of parameters are amplified by the complexity of the modelling approach increasing the uncertainty and reducing the reliability connected with a model's application. For this reason, a parsimonious integrated modelling approach has been developed and its uncertainty has been evaluated adopting the well known GLUE framework. For the purpose of the study, the uncertainty analysis has been applied to a "semi-hypothetic" case study obtained connecting Fossolo catchment (Bologna-Italy) to the Oreto river near Palermo (Italy).

Feeding troubles following delayed primary repair of esophageal atresia.

Severe feeding troubles were recorded in five babies with long-gap esophageal atresia who underwent, between 1985 and 1990, a delayed primary anastomosis after spontaneous growth of their esophageal stumps. A comparison with 20 cases of direct esophageal anastomosis, operated on in the same period, was carried out by means of recorded esophagrams, pH monitoring and questionnaires charting the growth pattern and feeding habits of the patients. Bottle feeding, and, later on, the introduction of semi-solid foods was significantly retarded in the group of children with delayed primary anastomosis (labeled as group B) as well as height and weight parameters. Failure to complete feeds, dysphagia, vomiting, coughing, choking and recurrent respiratory symptoms were also significantly more common in this group than in the primary anastomosis group (labeled as group A) even in the absence of stricture. Variable degrees of disordered esophageal motility were present in all patients but pooling of the contrast medium, retrograde flow and delayed clearing of the esophagus were more frequent in group B. No patient was shown to have associated hiatal hernia. A 24 hour pH recording showed severe gastroesophageal reflux in 4 out of 13 cases of group A and in 3 out of 5 cases of group B. Clearing times were significantly delayed in all refluxing children. Our data suggest that the retarded start of oral feeding and swallowing coordination in patients with delayed primary anastomosis add further negative factors to their congenitally impaired esophageal motility, causing protracted dysphagia which represents a major problem for both family and hospital staff.

[Ingestion of caustics in childhood: proposal for a therapeutic protocol]. / Ingestione da caustici nell'infanzia: proposta di un protocollo terapeutico.

Caustic ingestion is a traumatic event not rare in the infancy. The authors, after a brief discussion of their cases and after a revision of the literature, propose a therapeutic protocol for the treatment of caustic ingestion in the infancy. This protocol is based on the esophagoscopy in the first day and on the antibiotic and corticotherapy in the first two weeks. When there is an esophageal stenosis, the authors propose weekly esophageal dilatations.

[Ectopic bronchogenic cyst]. / Cisti broncogena ectopica.

The authors report a case of ectopic bronchogenic cyst. They review the literature and don't find any other similar case. This case is well explained by the embryology.

[Omphalocele: 10-year-experience]. / Onfalocele: dieci anni di esperienza.

We review our experience of 32 cases of omphalocele treated in the last ten years. Improved neonatal intensive care unit, as well as other support care measures, allowed to extend even to the large defects the indication to radical primary repair. Our experience has supported that this is the method of choice in almost all cases. At present the surgical success depend on associated anomalies, cardiac especially (25% in our series), and on development of sepsis. Analysis of the results shows an overall mortality rate of 41% in the period 1973/1982, significantly decreased to 33% in the last five years.

[Unusual case of ano-rectal malformation]. / Inusuale caso di malformazione ano rettale.

The authors present an unusual case of anorectal malformation: it's an intermediate from with a cutaneous fistulous tract. This case is similar to that described in 1982 by the Japan study group of anorectal anomalies.

[Orchiopexy by the Stephens-Fowler method (thermographic evaluation of the results)]. / Orchiopessia secondo Stephens e Fowler (Valutazione termagrafica dei risultati).

The authors present 12 cases of orchiopexy second Stephens and Fowler. They discuss the surgical technique and focus their attention on the evaluation of the functional result: they stress the utility of the thermography in this evaluation.

[Neonatal gastric perforation. Description of a case]. / Perforazione gastrica neonatale. Descrizione di un caso.

The authors describe a case of neonatal gastric perforation with a large defect in the gastric musculature. Causes and mechanisms leading to gastric perforation are discussed.

Regina Margherita Children's Hospital, Turin, Paediatric Surgery Division.

Atresia of the colon was first described in the literature. The authors present 4 cases seen at the paediatric surgery division of the Regina Margherita Children's Hospital in Turin. After a brief discussion of the embryology, attention is focused on the treatment of this malformation.