Dialysis as a new pre-treatment technique for online bacterial counting

Real-time bacteriological counting technology is capable of providing an online profile of bacterial removal during the wastewater treatment process, and can enhance the safety of recycled water for potable water reuse. However, autofluorescence emanating from dissolved organic compounds present in treated wastewater interferes with the analysis. In this study, a novel approach is adopted, viz., dialysis treatment for the removal of dissolved interfering substances from treated wastewater, and the efficiency of this treatment protocol is evaluated as a pre-treatment technique for real-time bacteriological counting. Dialysis using membranes having a molecular weight cut-off (MWCO) of 1000 kDa and 6?8 kDa were found to successfully reduce the intensity of autofluorescence emitted from the interfering substances; whereas the courser dialysis membrane having a MWCO of 1000 kDa was found to be more effective in removing the interfering substances. Here we demonstrate for the first time that continuous online dialysis treatment aids in the direct determination of the bacterial counts in ultrafiltration- and membrane bioreactor-treated wastewaters. The results of the study indicate that the dialysis pre-treatment technique is effective for continuously reducing the concentration of interfering substances in treated wastewater, and thus allows for direct online counting of bacteria

Online monitoring of bromate in treated wastewater: implications for potable water reuse

Continuous monitoring of bromate ions, a disinfection by-product of the ozonation of wastewater, may improve the safety of recycled water for potable use. A recently developed elemental analyzer can determine bromate ion concentrations online. However, dissolved organics present in wastewater interfere with the detection of bromate ions. The aim of this study was to develop a nanofiltration (NF) membrane-based pre-treatment system to remove the interfering substances present in treated wastewater prior to the online analysis. The NF pre-treatment system was optimized to ensure the removal of the interfering substances from the membrane bioreactor (MBR)-treated wastewater without altering the bromate ion concentration. We determined a permeate flux of 1 L m−2 h−1 and a feed temperature of 35 °C as optimal pre-treatment conditions for online analysis. Furthermore, the continuous monitoring of MBR-treated wastewater, containing different bromate ion concentrations (0-12 μg L−1), for three days revealed a strong correlation between the concentrations determined using the online analyzer and liquid chromatography coupled with tandem mass spectrometry. Thus, this study demonstrates the potential utility of the online bromate ion analyzer coupled with NF pre-treatment system to monitor the rate of bromate ion formation during ozonation

Diagnostic d'un nez rouge

LILLE2-BU Santé-Recherche (593502101) / SudocPARIS-BIUM (751062103) / SudocSudocFranceF

安全な飲料水を生産するための自動水質計測手法の開発

長崎大学学位論文 [学位記番号]博（工）甲第110号 [学位授与年月日]令和4年2月16

L'obésité en Lorraine (prévalence de l'obésité parmi les patients consultant en médecine générale en Lorraine et attitude du médecins traitant face à ces patients)

Cette étude, menée dans huit cabinets de médecine générale en Lorraine, permet dans la première partie, de déterminer la prévalence du surpoids et de l'obésité en zone franche urbaine, en centre ville ou en zone suburbaine . La prévalence l'obésité est nettement supérieure en ZFU. Les médecins ont été interrogés afin d'évaluer leur comportement face à un patient obèse. Le médecin généraliste éprouve des difficultés à aborder la thématique de l'obésité et il manque de temps pour prendre en charge les patients. Il se se souvent en décalage avec le patient concernant les critères diagnostiques et les solutions proposées. La 2ème partie de cette étude permet de caractériser la population obèse consultant en ZFU. Nous avons interrogé 100 patients à leur domicile. Notre échantillon est composé majoritairement de femmes. Leur âge moyen est 59,3 ans. Leurs revenus sont modestes. Les patients sont plutôt sédentaires. Ils s'approvisionnent en supermarché standard et consacrent entre 300 et 400 euros par mois à le alimentation. Leurs repas se déroulent dans une atmosphère familiale mais souvent devant la télévision. Ils fréquentent peu les lieux de convivialité. Le rappel des 24 heures a conduit a une sous-estimation des apports alimentaires ce qui suggère qu'il ne devrait plus être utilisé en médecine générale. L'alimentation des patients des ZFU se rapproche des recommandations du PNNS pour la consommation fruits légumes, des viandes et des produits laitiers. Les patients sont majoritairement gênés par leur obésité et ont conscience de ses conséquences. Ils sollicitent une prise en charge à la fois individuelle, par une diététicienne, et une éducation de groupe dans leur quartier.NANCY1-SCD Medecine (545472101) / SudocSudocFranceF

Dermatosis Papulosa Nigra (prévalence chez la femme enceinte au CHU de Kigali et étude du mode de transmission)

LILLE2-BU Santé-Recherche (593502101) / SudocPARIS-BIUM (751062103) / SudocSudocFranceF

Development of high-integrity reverse osmosis membranes for enhanced removal of microorganisms

Improved integrity of reverse osmosis (RO) membranes for pathogenic microorganisms can enhance the microbiological safety of potable water reuse. This study aimed to produce a high-integrity RO membrane that is less prone to defects or failures of the polyamide skin layer. The commercial track-etched (TE) microfiltration membranes with uniform pore sizes of 0.2 μm were adopted as a robust support layer. The polyamide skin layer was successfully formed by creating a thin m-phenylenediamine (MPD) layer using a spin coater before the interfacial polymerization. The best TE-based RO membranes had a pure water permeability of 1.1 L/m2 hbar and a salt rejection of 97 %. The field emission scanning electron microscopy revealed that the skin layer thickness of the TE-based membrane (approx. 31 nm) was equivalent to a commercial RO membrane. The removal of bacteria-sized particles (0.5 μm fluorescent microspheres) by the fabricated TE-based membrane (8.6-log) was greater than that by the commercial RO membrane taken out from an RO membrane element (7.8-log). Although complete removal of bacteria-sized particles was not achieved with small TE-based RO membrane coupons, this study established a viable protocol for producing a high-integrity RO membrane by forming the polyamide skin layer on the TE support layer.Desalination, 572, art. no. 117155; 202

Application of stabilized hypobromite for controlling membrane fouling and N-nitrosodimethylamine formation

Chloramination is a conventional and successful pre-disinfection approach to control biological fouling for reverse osmosis (RO) treatment in water reuse. This study aimed to evaluate the possibility of using a new disinfectant?stabilized hypobromite?in controlling membrane fouling and the formation of a particular carcinogenic disinfection byproduct (DBP)?N-nitrosodimethylamine (NDMA). Our accelerated chemical exposure tests showed that the new disinfectant reduced the permeability of a polyamide RO membrane permeability from 6.7 to 4.1 L/m2hbar; however, its treatment impact was equivalent to that of chloramine. The disinfection efficacy of stabilized hypobromite was greater than that of chloramine when evaluated with intact bacterial counts, which suggests its potential for mitigating membrane biofouling. Additional pilot-scale tests using synthetic wastewater demonstrated that pre-disinfection with the use of stabilized hypobromite inhibits membrane fouling. Among 13 halogenated DBPs evaluated, the formation of bromoform by stabilized hypobromite was higher than that by chloramine at a high dose of 10 mg/L, thus suggesting the need for optimizing chemical doses for achieving sufficient biofouling mitigation. NDMA formation upon stabilized hypobromite treatment in two different types of actual treated wastewaters was found to be negligible and considerably lower than that by chloramine treatment. In addition, NDMA formation potential by stabilized hypobromite was 2?5 orders of magnitude lower than that by chloramine. Our findings suggest the potential of using stabilized hypobromite for controlling NDMA formation and biofouling, which are the keys to successful potable water reuse