Discharge quality from municipal wastewater treatment plants and the Sludge Biotic Index for activated sludge: integrative assessment

Abstract Wastewater treatment plants (WWTPs) are scrutinized by Environmental Authorities particularly regarding the compliance to discharge limit values fixed by national and local regulations. An integrated approach is necessary to achieve the objectives established with Directive 2000/60/EC (WFD) considering the ecological status of the receiving water body and the quality of the discharge. Specifically, documentary, technical, management and analytical controls should be developed. Moreover, integrative information on the behaviour of the activated sludge in the aeration tank can be useful for plant managers as well as for the regulating Authorities. The study presents the experience concerning WWTP regulation considering the analytic assessment of the discharge as well the monitoring of the Sludge Biotic Index (SBI) for activated sludge. Data from monitoring during the period 2008–14 on SBI values and chemical and microbiological data on the discharges of a sample of 35 WWTPs in the province of Venice (north-east Italy, Veneto region) are presented and discussed. Together with chemical and microbiological analysis, the SBI appears to be a highly useful index for the integrative assessment of plant functionality, in particular when monitoring and identifying critical situations that can determine the exceedance of discharge limit values. The SBI method, in an integrated control approach, can be used for small and medium sized WWTPs that only treat domestic wastewaters. In a case by case assessment this may even substitute part of the analytical monitoring carried out in the WWTPs' control process

DNA HLA-DRB1 analysis in children of positive mothers and estimated risk of vertical HIV transmission.

RFLP HLA-DRB I analysis was performed on a total of 83 children born from HIV -infected mothers, 35 of whom were shown to be HIV -infected, while 48 reverted from seropositivity to seronegativity, indicating that they were not infected. Moreover, 89 healthy children were used as controls. It has been found that DRBI-14a and DRBI-13a.4 alleles were not present in the HIV-infected children, but were found in the sero-reverted (HIV-uninfected) children (in the proportion of 9·6 per cent and 5·3 per cent, respectively), and in the controls (5·6 per cent and 3·9 per cent, respectively). The possible correlation between DR and risk of HIV transmission from mother to baby was analysed considering every single allele, estimated by the ratio between the number of infected children and the number of all children born from seropositive mothers. There was also introduced a statisticGfor the control of 'statistical validity' of data

Effect of atmospheric nitric oxide (NO) on measurements of exhaled NO in asthmatic children

The measurement of exhaled nitric oxide concentrations [NO] may provide a simple, noninvasive means for measuring airway inflammation. However, several measurement conditions may influence exhaled NO levels, and ambient NO may be one of these. We measured exhaled NO levels in 47 stable asthmatic children age 5 to 17 years and in 47 healthy children, gender and age matched. Exhaled [NO] in expired air was measured by a tidal breathing method with a chemiluminescence analyzer, sampling at the expiratory side of the mouthpiece. NO steady\u2010state levels were recorded. In order to keep the soft palate closed and avoid nasal contamination, the breathing circuit had a restrictor providing an expiratory pressure of 3\u20134 cm H2O at the mouthpiece. To evaluate the effect of [NO] in ambient air, measurements were randomly performed by breathing ambient air or NO\u2010free air from a closed circuit. Breathing NO\u2010free air, exhaled [NO] in asthmatics (mean \ub1 SEM) was 23.7 \ub1 1.4 ppb, significantly higher (P < 0.001) than in healthy controls (8.7 \ub1 0.4 ppb). Exhaled NO concentrations measured during ambient air breathing were higher (49 \ub1 4.6 ppb, P < 0.001) than when breathing NO\u2010free air (23.7 \ub1 1.4 ppb) and were significantly correlated (r = 0.89, P < 0.001) with atmospheric concentrations of NO (range 3\u2013430 ppb). These findings show that (1) exhaled [NO] values of asthmatic children are significantly higher than in healthy controls, and (2) atmospheric NO levels critically influence the measurement of exhaled [NO]. Therefore, using a tidal breathing method the inhalation of NO\u2010free air during the test is recommended. Pediatr Pulmonol. 1998; 26:30\u201334. \ua9 1998 Wiley\u2010Liss, Inc

Somatosensory pathway dysfunction in uremic children

Neurophysiological studies have shown defects in peripheral conduction in up to 75% of adults with end-stage renal disease (ESRD), though abnormalities of central conduction seem more variable. There are no comparable pediatric data. We therefore measured median nerve somatosensory evoked potentials (SEPs) in 10 children with ESRD, maintained by hemodialysis, who had no neurological signs or symptoms, and compared the results with those for age-matched controls. The latencies of N9, P14, N20 and P22, and interpeak latencies, N9-N20, N9-P14 and P14-N20, were not significantly different between the two groups (Student’s t test). However, the children with ESRD were significantly retarded in growth and when arm length was taken into account, a significant difference in peripheral conduction was revealed. There was no correlation with other indexes of disease severity (parathormone, aluminium, Hb, Na, K, Cl, BUN and creatinine). SEPs appear to reflect subclinical changes in peripheral conduction in sensory pathways in children with ESRD which are not correlated with other measures of disease severity. © 1991, All rights reserved