The importance of exact exchange—A methodological investigation of NO reduction in heme–copper oxidases

Abstract This paper describes the on-going pilot scale development of a new treatment process designed to remove radium-226 from uranium milling effluents. Presently, decants from Canadian uranium mining and milling tailings areas are treated with barium chloride to remove radium-226 prior to discharge into the environment. This is usually accomplished in large natural or man-made ponds which provide an opportunity for a (Ba,Ra)SO4 precipitate to form and subsequently settle. Sand filtration is sometimes used as a polishing step. This new process differs from conventional and other experimental processes in that it involves the use of a fluidized bed to facilitate the deposition of a (Ba,Ra)SO4 precipitate on a granular medium of high surface area. As a stand-alone treatment process, the new process is consistently able to reduce incoming radium-226 activity levels by 90-99%. Effluent levels of 10 pCi/L (0.370 Bq/L) or less have been achieved, depending on the influent activity levels. Recent testing of the process as a polishing step has demonstrated radium removal efficiencies up to 60% when the process influent was already less than 5 pCi/L (0.185 Bq/L). The process has been operated at temperatures ranging from 26°C down to 0.3°C with no reduction in efficiency. In contrast to treatment times in the order of days for conventional settling pond systems and hours for mechanical stirred tank/filtration systems, the new process is able to achieve these radium removal efficiencies in times on the order of one minute.

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Microbiological performance and salmonella dynamics in a wastewater depuration pond system of southeastern spain

Water Science & Technology ◽

10.2166/wst.1995.0492 ◽

1995 ◽

Vol 31 (12) ◽

pp. 239-248 ◽

Cited By ~ 5

Author(s):

Ana Emparanza-Knörr ◽

Francisco Torrella

Keyword(s):

Fecal Coliform ◽

No Reduction ◽

Agar Medium ◽

Microbiological Quality ◽

Total Coliform ◽

Fecal Coliforms ◽

Selective Media ◽

E Coli ◽

The Village ◽

Final Effluent

The Salmonella presence and the microbiological quality indicators, total and fecal coliforms and coliphages of E. coli C, have been studied in a overloaded wastewater lagoon system treating urban wastewatrers of the village of Guardamar del Segura (Alicante, Spain). Classical microbiological technology to detect salmonellae was used, including pre-enrichment, enrichment, selective media plating and biochemical and serological confirmation. Water was physicochemically characterized according to COD, SS, temperature, pH and dissolved oxygen. The selective migration step through Rappaport-Vassiliadis semisolid agar medium was essential for the consistent detection of Salmonella in the different lagoon effluents. Total and fecal coliform levels of up to 105-106 MPN/100 ml were detected in the final effluent. High coliphage concentrations of 103-104 pfu/ml were also found in the effluent waters. Salmonella was always detected in 100 ml samples and eventually reached an order of value of 103 MPN/100 ml. Total coliform reduction was higher in the anaerobic ponds whereas fecal coliforms were more efficiently eliminated in the facultative (mostly “anoxic”) lagoons. Coliphage reduction was higher in the facultative lagoons when compared to the anaerobic ponds. On many occasions, no reduction or eventual increment of the concentration of salmonellae was detected in the effluents from the anaerobic ponds compared to concentrations of the patohogen in the influent raw wasterwaters. The possibility exists for a capacity of Salmonella to multiply in the anoxic phase of the wastewater treatment, but the presence of microorganisms in raw sewage waters which could maskSalmonella detection with the enrichment methodology employed cannot be ruled out.

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Simultaneous NO reduction and Hg0 oxidation over Sb modified Mn/TiO2 catalyst

Materials Chemistry and Physics ◽

10.1016/j.matchemphys.2019.04.061 ◽

2019 ◽

Vol 232 ◽

pp. 88-98 ◽

Cited By ~ 1

Author(s):

Jian Liu ◽

Rui-tang Guo ◽

Xiao Sun ◽

Wei-guo Pan ◽

Zhong-yi Wang ◽

...

Keyword(s):

No Reduction ◽

Tio2 Catalyst

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468. Specimen pooling conserves additional testing resources when patients’ infection status is correlated: A simulation study

Open Forum Infectious Diseases ◽

10.1093/ofid/ofaa439.661 ◽

2020 ◽

Vol 7 (Supplement_1) ◽

pp. S300-S300

Author(s):

Jeffrey Rewley

Keyword(s):

Internal Medicine ◽

Simulation Study ◽

No Reduction ◽

Optimal Size ◽

Infection Status ◽

Heat Map ◽

Population Prevalence ◽

Additional Testing ◽

Batch Sizes ◽

Pooled Sample

Abstract Background In the early stages of a novel pandemic, testing is simultaneously in high need but low supply, making efficient use of tests of paramount importance. One approach to improve the efficiency of tests is to mix samples from multiple individuals, only testing individuals when the pooled sample returns a positive. Methods I build on current models which assume patients’ sero-status is independent by allowing for correlation betweenconsecutive tests (e.g. if a family were all infected and were all tested together). In this model, I simulate 10,000 patients being tested in sequence, with population sero-prevalence ranging from 1% to 25%, using batch sizes from 3 to 10, and assuming the increased probability of consecutive infections ranged from 0% to 50%. Results I find that as the likelihood of consecutive infected patients increases, the efficiency of specimen pooling increases. As well, the optimal size of the batch increases in the presence of clustered sequences of infected patients. Heat map indicating the manner in which the number of tests needed is reduced as population prevalence and correlation between cases changes. Red indicates that there is no reduction in the number of tests, and blue indicates a near 100% reduction in the number of tests, with intermediate colors indicating intermediate fractions. Conclusion This analysis indicates further improvements in specimen pooling efficiency can begained by taking advantage of the pattern of patient testing. Disclosures Jeffrey Rewley, PhD, MS, American Board of Internal Medicine (Employee)

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