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The extraction of Fe(III), Cr(III), and Ni(II) from stainless steel rinse water using non-dispersive extraction and strip dispersion membrane technology was carried out in a microporous hydrophobic hollow-fibre module contactor. The fibres were of polypropylene, whereas the organic extractant DP8R (bis(2-ethylhexyl) phosphoric acid) diluted in ExxsolD100 was used as the carrier phase. The rinse water containing the three elements was passed through the tube side, and the pseudo-emulsion formed by the organic phase of DP8R in Exxol D100 and an acidic strip solution were passed through the shell side in a counter-current operation; thus, a unique hollow fibre module was used for extraction and stripping. In non-dispersive extraction and strip dispersion technology, the stripping solution was dispersed into the organic membrane solution in a vessel with an adequate mixing device (impeller) designed to form strip dispersion. This pseudo-emulsion was circulated from the vessel to the membrane module to provide a constant supply of the organic phase to the membrane pores. Different hydrodynamic and chemical variables, such as variation in feed and pseudo-emulsion flow rates, strip phase composition, feed phase pH, and extractant concentration in the organic phase, were investigated. Mass transfer coefficients were estimated from the experimental data. It was possible to separate and concentrate the metals present in the rinse water using the non-dispersive extraction and strip dispersion technique.

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BACKGROUND: Alcohol is perceived to aid flexible endoscope channel drying, however we previously showed alcohol increased the time required to dry some channels with forced air versus water alone. Yet, alcohol may prevent microorganism outgrowth during storage. Drying endoscope channels has been shown to prevent outgrowth, but it is unknown if incomplete drying (<10 µL remaining) provides similar protection. METHODS: Endoscope channel test articles were used to determine the efficacy of 70%-30% alcohol flush for prevention of Pseudomonas aeruginosa outgrowth and drying efficiency. For non-alcohol flushed channels, the impact of forced air drying on outgrowth of P. aeruginosa was determined. RESULTS: Alcohol flush (70%-30%) prevented outgrowth with little to no recovery of P. aeruginosa during ambient storage. 70% alcohol increased channel drying time by 1.5 or 3-fold compared to 50% alcohol or water, respectively. Forced air drying of non-alcohol flushed channels greatly reduced the initial contamination level and prevented outgrowth. Incomplete drying of contaminated channels was akin to no application of forced air. Applying forced air for more time than necessary to remove residual liquid did not completely eliminate the low level recovery of P. aeruginosa. CONCLUSIONS: Flushing with reduced concentrations of alcohol may provide a strategy to prevent microbial outgrowth while reducing drying time.

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During the temporal storage of municipal solid wastes (MSWs), pharmaceutically contained in MSWs may percolate into leachates and migrate into receiving waters via surface runoff. However, knowledge of their intra-event variations during the rainfall is quite limited. To fill in this gap, we collected runoff samples in a typical MSW transfer station over the full length of a rainfall event to comprehensively characterize the pharmaceutical contamination profiles. The results showed that 18 pharmaceuticals were detected in the runoff samples with high frequencies and concentrations ranging from below MQL to 18.6 µg/L. During the rainfall event, pharmaceuticals exhibited discrepant leachabilities as a result of different sorption capacities; two concentration peaks of each pharmaceutical were observed, suggesting the leaching effect by rainwater and the potential influence of human-related rinse. A further sampling campaign for one-week-long runoff samples generated by diurnal rinse water was conducted, and the results indicated comparable mass loads of pharmaceuticals in surface runoff receiving rinse water (0.37-8250 µg) to those in rainfall runoff (0.58-1754 µg), suggesting the similar discharge of pharmaceuticals from MSW transfer stations despite the weather. The estimated per capita discharge load of caffeine, one of the typical Pharmaceuticals, from MSW transfer stations was 4383 ng capita-1 d-1, higher than that in other emission sources, e.g. municipal wastewater effluent, indicating an overlooked influence of MSW transfer stations on its contamination in the surface waters in Shanghai.

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Cr(VI) is a toxic metal pollutant existing in industrial effluents. In this study, Fe3O4 and layered double hydroxide (LDH) were inserted into the litchi shell (LS) successively by the co-precipitation method to synthesize the modified magnetic litchi shell adsorbent (MMLS) for removing Cr(VI). The advantageous structure characteristics of MMLS were confirmed by XRD, FT-IR, SEM and the hysteresis loop characterization. The batch experiments of optimizing the conditions (pH, adsorbent dosage, initial concentration, coexisting ions) for removing Cr(VI) were accomplished to in simulated wastewater at room temperature. And the optimal pH of 3 and initial concentration of 100 mg/L in simulated wastewater were similar to that in the actual chrome-plated rinse water with the stable MMLS. The effect of coexisting ions indicated anions and Cr(VI) competed with each other for the adsorption site, but the interactions were negligible in actual chrome-plated rinse water. Chemisorption as a rate-limiting step was confirmed with a good fit of pseudo-second-order kinetics. And the adsorption behavior of MMLS can not be explained by a single theory according to Sips model. The desorption and recycle experiments demonstrated MMLS was reusable in actual chrome-plated rinse water.

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BACKGROUND: Microbiologic surveillance of flexible gastrointestinal endoscopes is recommended in several guidelines as the primary means of identifying reprocessing failures. This study aimed to evaluate the contamination level and prevalence of bacteria of post-reprocessing endoscopes and to access whether using a pump-assisted sampling method (PASM) improves the sensitivity of culture. METHODS: All 59 endoscopy units in Tianjin, China, were investigated. The PASM and the conventional flushing sampling method (CFSM) were used to compare the results of the microbial culture. Logistic regression analysis was used to identify the influencing factors. RESULTS: One hundred four (56.52%) flushing channel samples of gastrointestinal endoscopes were positive for culture, and the maximum bacterial concentration was 14,100 colony-forming units (CFU)/channel. One hundred fifty-one (82.07%) flushing samples were qualified according to the national standard of China (≤ 20 CFU/channel). The qualified rate of the samples collected by PASM was significantly lower than the qualified rate by CFSM (65.52% vs 89.68%). Using PASM (odds ratio [OR]: 4.257; 95% confidence interval [CI]: 1.870-9.690) would increase the sensitivity of culture. The use of purified water (OR: 0.288; 95% CI: 0.102-0.814) could reduce the risk of endoscope reprocessing failure. CONCLUSION: Many endoscopes fail to meet the national standard for microbial culture after reprocessing. Our results suggest that using a pump-assisted method could increase the sensitivity of the test.

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Raw chicken products are major causes of human foodborne salmonellosis worldwide. In particular, there is a significant risk of human exposure to Salmonella originating from the chicken slaughtering process. Controlling the contamination of chicken carcasses by Salmonella has been a considerable challenge in chicken-slaughtering facilities and involves routine microbiological monitoring using reliable detection methods. Simple and rapid detection methods, particularly those capable of determining cell viability, will significantly facilitate routine monitoring of Salmonella Here, we report an invA-based loop-mediated isothermal amplification method coupled with a simple propidium monoazide treatment (PMA-LAMP) for simple and rapid detection and quantification of viable Salmonella in rinse water of chicken carcasses. In this study, PMA-LAMP consistently gave negative results for isopropanol-killed Salmonella with concentrations up to 8.0 × 106 CFU/reaction. The detection limit of PMA-LAMP was 8.0 × 101 CFU/reaction with viable Salmonella in both pure culture and rinse water of chicken carcasses, and 10-fold lower than a conventional polymerase chain reaction coupled with PMA (PMA-PCR) targeting invA There was a high correlation (R2 = 0.99 to 0.976) between LAMP time threshold (TT) values and viable Salmonella with a quantification range of 1.0 × 103 to 1.0 × 108 CFU/mL in pure culture and rinse water of chicken carcasses. The PMA-LAMP assay took less than 2 h to detect Salmonella contaminated in test samples. Therefore, this simple and rapid method will be a very useful tool to detect live Salmonella contamination of chicken carcasses without pre-enrichment at the slaughterhouse where sanitizing treatments are commonly used.

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BACKGROUND: The penultimate stage in endoscope reprocessing is the final rinse with water following terminal disinfection. This requires a degree of microbiological and chemical control of the quality of the final rinse water. AIM: To report experience gained over five years of testing, reporting and managing the quality of final rinse water for endoscopic devices. METHODS: Three endoscope reprocessing units, each comprising five endoscope washer-disinfectors (EWDs) supplied by two reverse osmosis (RO) water units, were subjected to weekly monitoring and control of final rinse water quality. EWDs were subjected to nightly thermal self-disinfection, and RO units were subjected to periodic sanitization with peracetic acid. Final rinse water samples were processed periodically for total viable counts (TVCs), Pseudomonas spp., endotoxins, conductivity, environmental mycobacteria and Legionella spp. FINDINGS: Over the five-year study period (2008-2013), no Pseudomonas spp., environmental mycobacteria or Legionella spp. were isolated from endoscopy rinse water. All conductivity readings were below 30 µs/cm. Endotoxin levels fluctuated over the recommended cut-off of 0.25 EU/mL, with no correlation with TVCs. Trend analysis of TVCs established alert and action limits. Apart from the supply water of one EWD becoming contaminated with Aspergillus spp., there have been no interruptions to operational capacity of the endoscope reprocessing units. CONCLUSIONS: Quality control principles coupled with appropriate thermal and chemical disinfection of EWDs resulted in the achievement of microbiological standards for final rinse water. A co-ordinated team approach between the microbiology department, infection control department, endoscope unit managers and estates department is required to achieve this degree of success.

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