Multi-target assessment of advanced oxidation processes-based strategies for indirect potable reuse of tertiary wastewater: Fate of compounds of emerging concerns, microbial and ecotoxicological parameters.

Two advanced oxidation processes (AOPs), namely ozone/H2O2 and UV/H2O2, were tested at pilot scale as zero-liquid-discharge alternative treatments for the removal of microbiological (bacteria and viruses), chemical (compounds of emerging concern (CECs)) and genotoxic responses from tertiary municipal wastewater for indirect potable reuse (IPR). The AOP treated effluents were further subjected to granular activated carbon (GAC) adsorption and UV disinfection, following the concept of multiple treatment barriers. As a reference, a consolidated advanced wastewater treatment train consisting of ultrafiltration, UV disinfection, and reverse osmosis (RO) was also employed. The results showed that, for the same electrical energy applied, the ozone/H2O2 treatment was more effective than the UV/H2O2 treatment in removing CECs. Specifically, the ozone/H2O2 treatment, intensified by high pressure and high mixing, achieved an average CECs removal efficiency higher than UV/H2O2 (66.8% with respect to 18.4%). The subsequent GAC adsorption step, applied downstream the AOPs, further improved the removal efficiency of the whole treatment trains, achieving rates of 98.5% and 96.8% for the ozone/H2O2 and UV/H2O2 treatments, respectively. In contrast, the ultrafiltration step of the reference treatment train only achieved a removal percentage of 22.5%, which increased to 99% when reverse osmosis was used as the final step. Microbiological investigations showed that all three wastewater treatment lines displayed good performance in the complete removal of regulated and optional parameters according to both national and the European Directive 2020/2184. Only P. aeruginosa resulted resistant to all treatments with a higher removal by UV/H2O2 when higher UV dose was applied. In addition, E. coli STEC/VTEC and enteric viruses, were found to be completely removed in all tested treatments and no genotoxic activity was detected even after a 1000-fold concentration. The obtained results suggest that the investigated treatments are suitable for groundwater recharge to be used as a potable water source being such a procedure an IPR. The intensified ozone/H2O2 or UV/H2O2 treatments can be conveniently incorporated into a multi-barrier zero-liquid-discharge scheme, thus avoiding the management issues associated with the retentate of the conventional scheme that uses reverse osmosis. By including the chemical cost associated with using 11-12 mg/L of H2O2 in the cost calculations, the overall operational cost (energy plus chemical) required to achieve 50% average CECs removal in tertiary effluent for an hypothetical full-scale plant of 250 m3/h (or 25,000 inhabitants) was 0.183 €/m3 and 0.425 €/m3 for ozone/H2O2 and UV/H2O2 treatment train, respectively.

[Endoscopic treatment of intestinal anastomotic leakage in low anterior resection of the rectum by using fibrin adhesive. Our experience]. / Trattamento endoscopico delle deiscenze anastomotiche nelle resezioni anteriori del retto mediante applicazione di colla di fibrina. Nostra esperienza.

BACKGROUND: Personal experience about treatment of anastomotic leakage in low anterior resection of the rectum by using human fibrin adhesive "Tissucol" is reported. METHODS: Eight cases of anastomotic leakage treated with using human fibrin adhesive "Tissucol", are analyzed in a retrospective study. Patients had three/six months-one year follow up. Treatment with human fibrin adhesive "Tissucol" was performed in our Endoscopic ambulatory. Six cases had either an immediate resolution or an ambulatorial follow-up; in 2 cases only, general complications forced to a prolonged hospital stay. The study concerns 58 patients subjected to low anterior resection of the rectum and endoscopic treatment of 8/58 patients with anastomotic leakage. Fistulas were sealed with human fibrin adhesive "Tissucol" by using flexible endoscope. Anastomotic leakage identification leakage was made and low anterior resection of the rectum and sealing with human fibrin adhesive "Tissucol" were performed. RESULTS: Complete sealing of fistula and rectum patent. CONCLUSIONS: The excellent results obtained with this non invasive and fast treatment, easily practicable even in ambulatorial regimen, lead the authors to consider it effective and as first-choice treatment of this dangerous complication. The cost/benefit ratio is favorable if compared with the long hospital stay required for other treatments, which also present loaded high morbidity and mortality.

Assessment of a novel screening test for neutrophil collagenase activity in the diagnosis of periodontal diseases.

BACKGROUND: Increased levels of active neutrophil collagenase (MMP-8) in the gingival crevicular fluid (GCF) are associated with progressive periodontitis. The measurement of this enzyme in GCF could facilitate diagnosis. However, assays with sufficient sensitivity to detect collagenase in whole-mouth GCF currently use radiolabeled substrates and require several days to complete. To provide more rapid analyses of collagenase activity that are better adapted to clinical studies, we developed and validated a novel assay (soluble biotinylated-collagen assay: SBA) based on chemiluminescent detection of biotinylated collagen digestion products. METHODS: The concordance of the novel SBA assay with a radioactive collagen substrate assay was assessed by parallel analyses of enzyme from 35 neutrophil preparations and from 41 samples of GCF from periodontitis patients, followed by Pearson correlation analysis. To test whether the assay appropriately measured MMP-8 activity, enzyme activity was assessed after incubation with specific collagenase blockers. We examined the diagnostic utility of the SBA in cross-sectional and longitudinal analyses of 125 patients with adult periodontitis, 5 patients with early-onset periodontitis, 1 edentulous patient, and in 32 control patients without periodontitis. RESULTS: The assay detected <56 pg collagen degraded/hour/microl sample, which is comparable to the most sensitive radioactive assay. The total assay time was 22 hours and reproducibility on replicate measurements was high (r = 0.96). In direct comparisons of MMP-8 activity in GCF with enzyme from peripheral blood neutrophils using the SBA and radioactive assays, there was a high correlation (r = 0.97). As expected, EDTA and TIMP-1 and -2, known inhibitors of MMP-8, completely blocked enzyme activity with this assay. Cross-sectional and longitudinal analyses of GCF showed that MMP-8 activity was >18-fold higher in severe periodontitis than in stable periodontitis and decreased to <25% of pretreatment levels following therapy. Based on measurements of collagenase activity in different disease groups, we estimated a value of 80 nano units as a threshold for severe periodontitis. CONCLUSIONS: These results indicate that active MMP-8 is detected in GCF by a novel assay that is specific, simple, rapid, and reproducible and which may facilitate diagnostic discrimination between stable and progressive lesions.

Identification of blast cells in peripheral blood through automatic assessment of nuclear density: a new tool for monitoring patients with acute leukaemia.

The Technicon H*1 haematology system is provided with a new method for basophil count, neutrophil lobularity assessment and detection of blasts in peripheral blood through automated measurement of nuclear density. We compared the results of the H*1 blast flag with those of the microscope examination in 131 peripheral blood samples from 43 patients with acute leukaemia in different phases of their disease, to determine the degree of sensitivity and specificity of the system in this setting. In six patients at diagnosis or in overt relapse, all having large percentages of blasts at the manual differential count, a typical deformation of the profile of the mononuclear cell population on the display was consistently observed, regardless of the morphological subtype of leukaemic cell which was involved. Amongst 34 samples with 4-95% morphologically recognizable blasts on the peripheral blood film, the sensitivity of the system was 100% with no false negatives at all. In 43 samples, on the other hand, the H*1 blast flag was positive in the absence of any morphological evidence of blasts on the smear. These 'false positives', however, were always obtained from leucopenic patients who had more than 12% blast infiltration in the bone marrow, compared to the 0-6% value that was found in patients with a negative H*1 blast flag. These results suggest that the H*1 system is a highly sensitive tool for the detection in peripheral blood of even small concentration of leukaemic cells, which escape morphological identification.