A comparison between two full-scale MBR and CAS municipal wastewater treatment plants: techno-economic-environmental assessment

A holistic assessment procedure has been used in this study for comparing conventional activated sludge (CAS) and membrane bioreactor (MBR) processes for the treatment of municipal wastewater. Technical, social, administrative, economic and environmental impacts have been evaluated based on 1 year of operational data from three full-scale lines (one MBR and two CAS) working in parallel in a large municipal treatment plant. The comparative assessment evidences a slight advantage of the conventional process in the studied case, essentially due to lower costs, complexity and energy consumption. On the other hand, the MBR technology has a better social acceptance and similar overall environmental footprint. Although these results are influenced by site-specific parameters and cannot be generalized, the assessment procedure allowed identifying the most important factors affecting the final scores for each technology and the main differences between the compared technologies. Local conditions can affect the relative importance of the assessed impacts, and the use of weighting factors is proposed for better tailoring the comparative assessment to the local needs and circumstances. A sensitivity analysis on the weighted final scores demonstrated how local factors are very important and must be carefully evaluated in the decision making process.     

Outcome of fetal echogenic bowel: A systematic review and meta-analysis

The main aim of this systematic review was to explore the outcome of fetuses with isolated echogenic bowel (EB) on antenatal ultrasound. Inclusion criteria were singleton pregnancies with isolated EB no associated major structural anomalies at the time of diagnosis. The outcomes observed were: chromosomal anomalies, cystic fibrosis (CF), associated structural anomalies detected only at follow-up scans and at birth, regression during pregnancy, congenital infections, intra-uterine (IUD), neonatal (NND) and perinatal (PND) death. Twenty-five studies (12 971 fetuses) were included. Chromosomal anomalies occurred in 3.3% of the fetuses, mainly Trisomy 21 and aneuploidies involving the sex chromosomes. Cystic fibrosis occurred in 2.2%. Congenital infections affected 2.2%, mainly congenital Cytomegalovirus (CMV) infection. The majority of fetuses with EB experienced regression or disappearance of the EB at follow-up scans. Associated anomalies were detected at a follow-up scan in 1.8%. Associated anomalies were detected at birth and missed at ultrasound in 2.1% of cases. IUD occurred in 3.2% of cases while the corresponding figures for NND and PND were 0.4% and 3.1%. Fetuses with EB are at increased risk of adverse perinatal outcome, highlighting the need for a thorough antenatal management and postnatal follow-up. Assessment during pregnancy and after birth should be performed in order to look for signs of fetal aneuploidy, congenital infections and associated structural anomalies.     

Prenatal diagnosis of ventricular aneurysm: a report of two cases and a review

Ventricular aneurysms have rarely been reported prenatally. Their prognosis is variable depending on factors such as early detection, their relative size in comparison to the ventricular cavity, growth on follow-up, and signs of cardiac failure. In view of the fact that it may be useful to report on additional cases in order to make available further information on aetiology, prognosis and neonatal management, we hereby report on two cases of ventricular aneurysm with good mid-term prognosis. One case of apical aneurysm of the left ventricle was associated with a muscular ventricular septal defect, the features of which are compatible with a fetal myocardial infarction and ventricular septal rupture in absence of coronary artery anomalies as demonstrated by catheterisation. Another case of sub-tricuspidal aneurysm of the right ventricle associated with mitral prolapse appears to be a component of diffuse connective dysplasia. Despite the early gestational age at diagnosis, the large size of the aneurysm and the associated defect, both the infants were asymptomatic in infancy prompting a conservative management. Copyright © 2002 John Wiley & Sons, Ltd.     

A risk index methodology for potentially polluting marine sites

Attempting to assess the risk of a release from a potentially polluting marine site (PPMS) can be a very subjective process. The Marine Site Risk Index (MaSiRI) is designed to provide a more objective approach to this process by adopting a table-based evaluation scheme, while still allowing for the inevitable unknown conditions by including a subjective ‘expert correction’ in a suitably controlled manner. Building on a geographic database of PPMS records, the MaSiRI algorithm applies data filters to remove PPMS records for which it is not applicable and then estimates a basic risk index based on core data that almost all sites would contain. It can then refine the results for those sites that have auxiliary data, varying the assessed risk as appropriate, according to standard rule-sets. A risk level of confidence is computed and adjusted to express dynamic confidence in the risk value (e.g., due to reliance on estimates rather than measured values), and where appropriate an upper and lower bound of risk can be used to assess the range of values associated with an estimated parameter. This information can be visualized by a composite quality symbol proposed here. MaSiRI is demonstrated on three illustrative shipwrecks and then compared against the DEvelopment of European guidelines for Potentially Polluting (DEEPP) project database from the Pelagos Sanctuary in the western Mediterranean. The aggregate results of the comparison are broadly similar to DEEPP, within the limits of the comparison, but provide a more detailed analysis in the case of estimated pollutant volume and ubiquitous assessment of levels of confidence.     

Practical applications of the fenton reaction to the removal of chlorinated aromatic pollutants

BACKGROUND: Chlorophenols (CPs) constitute a group of organic pollutants that are introduced into the environment as a result of several man-made activities, such as uncontrolled use of pesticides and herbicides, and as byproducts in the paper pulp bleaching. Promising removal technologies of chlorinated aromatics consist in the application of advanced oxidation processes (AOPs) that can provide an almost total degradation of a variety of contaminants. Among these, wide application find Fenton systems based on generation of reactive species having a high oxidizing power, such as hydroxyl radical HO*. Our objective was that of determining the overall degradation efficiency of the model compound 2,4-dichlorophenol (DCP) by thermal Fenton-type oxidation systems with a view toward defining in more details relevant process parameters, the effect of reaction temperature and of co-catalyst Cu2+. METHODS: Reaction conditions were similar to those generally adopted as optimal in many practical applications, i.e. pollutant/Fe2+ (as FeSO4) ratio ca. 20, Fe2+/Cu2+ (co-catalyst) 2:1, pH adjusted and controlled at pH 3, and H2O2 in excess (up to four-fold over the stoichiometric amount required for complete mineralization). RESULTS AND DISCUSSION: The results demonstrate that it is advantageous to carry out the reaction at a temperature markedly higher (70 degrees C) than ambient. The stepwise addition of H2O2 in aliquots yields an efficient transformation, while allowing a convenient control of the reaction exothermicity. Under these conditions, the essentially complete removal of the initial DCP is accomplished using just one equiv of H2O2 during 15 min; excess H2O2 (5 equivalents) yields extensive substrate mineralization. Also relevant, at 70 degrees C dechlorination of the initial DCP (and of derived reaction intermediates) is remarkably extensive (3-5% residual TOX), already with the addition of 1 equiv of H2O2. At the end of the reaction, IC and IC-MS analyses of the solution reveal that only low-molecular weight carboxylic acid (acetic, formic, oxalic, malonic, tartaric, etc.) contribute to the residual TOC. CONCLUSIONS: The whole of the results herein point to the advantage of performing the process at temperatures substantially higher than ambient (70 degrees C). Under the conditions adopted, almost complete degradation of the initial toxic compound can be achieved using hydrogen peroxide in fair excess (e.g., 3.5 equiv H2O2). RECOMMENDATIONS AND OUTLOOK: In applying practical Fenton-type degradation systems to heavily polluted wastes, either for the pre-treatment of waters with a high COD value prior to biodegradation or for complete mineralization of pollutants, the set up of appropriate reaction conditions appears to be a key factor. Also, it is desirable to keep the concentration of iron salts within the lower limits in order to minimize the production and disposal of iron oxide sludges.     

Molecular/chemical ecology in sponges: evidence for an adaptive antibacterial response in<Emphasis Type="Italic"> Suberites domuncula</Emphasis>

Sponges (Porifera) represent the evolutionary oldest metazoan phylum still extant today. They have developed a complex Bauplan, based on the existence of structural and regulatory molecules; many of these have been cloned and analyzed in the past years. The demosponge Suberites domuncula has been used as a suitable model to demonstrate that these animals not only possess an adaptive immune response on the level of cytokines, but also, as pointed out here, on the level of synthesis of bioactive alkyl-lipid derivatives. From specimens of S. domuncula the two lyso-PAF (platelet-activating factor) compounds, 1-O-hexadecyl-sn-glycero-3-phosphocholine and 1-O-octadecyl-sn-glycero-3-phosphocholine, have been identified and characterized. These two lyso-PAFs showed pronounced anti-bacterial activity. In the central part of this paper it is shown that the level of synthesis of the lyso-PAF congeners increased in response to the model compound, the endotoxin lipopolysaccharide (LPS). Treatment of the tissue with LPS for 72 h substantially increased the synthesis. In order to prove that the lyso-PAFs are really synthesized by the sponge, the key enzyme of the alkyl-dihydroxyacetonephosphate pathway, i.e. alkyl-dihydroxyacetonephosphate synthase (ADS), was cloned from S. domuncula. This sponge enzyme comprises the characteristic features of metazoan ADS enzymes; it is increasingly expressed in the tissue and in the in vitro cell culture system after exposure to LPS. These data are taken as a strong indication that bioactive, low-molecular weight, non-proteinaceous lipid derivatives function in an adaptive manner in response to the endotoxin.Communicated by R. Cattaneo-Vietti, Genova     

Sister chromatid exchanges in first-trimester chorionic villi after in vivo and in vitro exposure to diagnostic ultrasound

A study was done to evaluate the effects of diagnostic ultrasound on sister chromatid exchange (SCE) in first-trimester chorionic villi under controlled technical conditions. Chromosome analysis was performed by the direct method using spontaneous mitoses from the cytotrophoblast layer, and SCE visualization was accomplished by a 72 h treatment with 5-bromodeoxyuridine (BrdU) at a concentration of 10μg/ml. The slides were stained with ac ridine orange. Immediately before first-trimester chorionic villus sampling, a group of ten pregnant women was exposed to diagnostic ultrasound for 20min (in vivo exposure). This group of patients was compared with a control group who were not exposed. A mean value of SCE/cell frequency of 4·2 ± 0·2 was found in the exposed pregnancies, while a value of 3·7 ± 0·2 was observed in the control group. After in vitro exposure of chorionic villi obtained from elective abortions, the frequency of SCE/cell did not differ significantly among samples with different exposures (1,2, and 3 h) and controls. The positive control (mitomycin C) yielded a significant increase in SCE frequency.     

Prenatal diagnosis of congenital human cytomegalovirus infection

Fifteen fetuses at risk of congenital human cytomegalovirus (HCMV) infection underwent prenatal diagnosis at 16–30 weeks' gestation by a combination of amniocentesis and fetal blood sampling. HCMV was isolated from the amniotic fluid in six patients, but HCMV-specific IgM was detected in only three of them. Two of the nine neonates, who were delivered following a negative prenatal diagnosis, had congenital HCMV infection diagnosed by virus isolation in the urine. The interval from infection to prenatal testing was 3 and 4 weeks in the two false-negative cases and ⩾ 7 weeks in the true-positive cases. Although timely testing for HCMV infection allows the option of termination of pregnancy, it may be flawed by false-negative results.     

Amiodarone treatment in pregnancy for dilatative cardiomyopathy with ventricular malignant extrasystole and normal maternal and neonatal outcome

Amiodarone treatment in pregnancy might be difficult to handle because of the long half-life of the drug (14–28 days up to 2 months) and because it reduces maternal and neonatal thyroid activity. Although short-term use in pregnancy has been described in cases of fetal supraventricular tachycardia, there are few reports on the chronic use of the drug. In this paper we describe our experience with amiodarone treatment in two pregnant sisters with familial dilatative cardiomyopathy and ventricular malignant extrasystole. Prolonged administration of amiodarone (400–200 mg/die) since the beginning of pregnancy did not have any adverse effects; maternal and neonatal thyroid function was normal, as was the neurological and motor development of the neonates.