Solving the problem at the source: Controlling Mn release at the sediment-water interface via hypolimnetic oxygenation

Long-Term Transformation and Fate of Manufactured Ag Nanoparticles in a Simulated Large Scale Freshwater Emergent Wetland

“…Vertical concentrationdepth profiles of dissolved manganese (Mn 2+ ), iron (Fe 2+ ), and oxygen (O 2 ) were measured at 1 mm scale resolution across the sediment−water interface (SWI) of the cores using a solid-state mercury−gold amalgam voltammetric microelectrode as described previously. 44 Details of the electrode construction and voltammetric scan parameters are provided in the SI. After voltammetric electrode profiling of sediment cores, the upper ∼2−3 cm of sediment from the cores was transferred into sterile glass containers.…”

Design and testing of a novel hypolimnetic oxygenation system to improve water quality in Lake Bard, California

“…Typical half-lives of reduced manganese in oxygenated waters are on the order of years, while half-lives of reduced iron are on the order of minutes to hours (Davison 1993, Wehrli et al 1995. A number of studies have observed that once released into the water column, manganese is resistant to oxidation via lake oxygenation (Gantzer et al 2009b, Bryant et al 2011. Observations in the lake contrasted with those in oxic sediment-water chambers which showed a net loss of manganese over the course of the experimental incubations (Table 2; Fig.…”

Study of the application of the water-lifting aerators to improve the water quality of a stratified, eutrophicated reservoir

“…Two major countermeasures are available for the anoxic condition in the lower water layer due to stratification: one strategy overcomes water stratification using artificial mixing techniques. The other aims to directly oxygenate the water in the deep layer with hypolimnetic oxygenation systems (Antenucci et al, 2005;Bryant et al, 2011;Chowdhury et al, 2014;Soltero et al, 1994). Even though de-stratification can improve the dissolved oxygen content in the hypolimnion by mixing it oxygen-enriched surface water, hypolimnetic oxygenation is more widely applied to mitigate anoxia in the hypolimnion.…”

“…Even though de-stratification can improve the dissolved oxygen content in the hypolimnion by mixing it oxygen-enriched surface water, hypolimnetic oxygenation is more widely applied to mitigate anoxia in the hypolimnion. This strategy retains natural stratification in order to preserve the habitat for the fauna living in the cold waters at the bottom, avoid the pollutant release that ensues from mixing the bottom sediment mixed with the surface water and reduce the operation cost (Beutel, 2006;Bryant et al, 2011;Gantzer et al, 2009;Toffolon et al, 2012).…”