Among early adopters of wastewater monitoring for SARS-CoV-2 have been colleges and universities throughout North America, many of whom are using this approach to monitor congregate living facilities for early evidence of COVID-19 infection as an integral component of campus screening programs. Yet, while there have been numerous examples where wastewater monitoring on a university campus has detected evidence for infection among community members, there are few examples where this monitoring triggered a public health response that may have averted an actual outbreak.

This study reexamines the mean velocity scaling as well as higher order turbulent moments in a uniform smooth open channel flow with three different aspect ratios. In the overlap region, the velocity profiles follow the classical logarithmic law. In the outer region, the mean velocity data at various aspect ratios collapse on to each other only when the length scale is suitably modified. This length scale is defined on the basis of a region of constant turbulence intensity close to the free surface and is equal to the depth of flow at large aspect ratios. The proposed new length scaling also provides for a positive value of the wake parameter. Furthermore, turbulence distributions including that of the Reynolds shear stress, and triple correlations and collapse onto a single line making them nearly independent of aspect ratio. Quadrant decomposition of the velocity data was used to quantify the differences in the turbulence structure at the three channel aspect ratios. The quadrant analysis shows that the turbulence in open channel is similar to that in both turbulent boundary layers and flow in two-dimensional channels when all turbulent events are included. When only the extreme events are considered, differences between open channel flow and turbulent boundary layers become significant. The conditional quadrant analysis reveals that the violent ejections do penetrate into the flow and they are responsible for producing large portion of the Reynolds shear stress. Some effects of aspect ratio are revealed when the ratio of the ejection to sweep events are calculated. The turbulent events with the higher aspect ratios tend to be closer to the two-dimensional channel data.

Hydrogen production from glucose using a mixed anaerobic culture was assessed under batch conditions by adjusting the initial pH and adding linoleic acid (LA). At an initial pH of 5.0, hydrogen ($1.9\mathrm{mol}{\mathrm{H}}_2{\mathrm{mol}}^{-1}$ glucose) was detected after the first glucose injection in the controls (no LA added). At the latter initial pH and in cultures fed $\mathrm{2,000}\mathrm{mg}{\mathrm{l}}^{-1}$ LA, the yield reached a maximum of $2.4\mathrm{mol}{\mathrm{H}}_2{\mathrm{mol}}^{-1}$ glucose when glucose was injected again. Hydrogen was detected after the second glucose injection in cultures with the initial pH adjusted to 5.0 and 6.0. In cultures receiving LA and adjusted to pH 7.6, the hydrogen yield reached $1.4\mathrm{mol}{\mathrm{H}}_2{\mathrm{mol}}^{-1}$ glucose when glucose was injected again. Acetate, propionate, and butyrate were detected under all conditions; however, the quantities were variable and dependent on the conditions examined. In comparison to the amount of volatile fatty acids produced, relatively low quantities of alcohols (ethanol, i-propanol, n-butanol, and i-butanol) were detected during the initial lag phase of $96\text{to}120\mathrm{h}$ .

This paper reports the results of an experimental study characterizing turbulence and turbulence anisotropy in smooth and rough shallow open-channel flows. The rough bed consists of a train of two-dimensional transverse square ribs with a ratio of the roughness height (k) to the total depth of flow (d) equal to 0.10. Three rib separations ( p/k ) of 4.5, 9, and 18 were examined. Here, p is the pitch between consecutive roughness elements and was varied to reproduce the classical condition of d - and k -type roughness. For each case, two-component velocity measurements were obtained using a laser Doppler velocimetry system at two locations for p/k=4.5 and 9: on the top of the rib and above the cavity, and an additional location for p/k=18 . The measurements allow examination of the local variations of the higher-order turbulent moments, stress ratios as well as turbulence anisotropy. Large variations of the turbulence intensities, Reynolds shear stress, turbulent kinetic energy and turbulence production ar...