We report the preparation and characterization of spinel-structured FeCo2O4 nanoparticles for the efficient and selective oxidation of sulfides. The as-prepared FeCo2O4 nanoparticles were characterized by powder X-ray diffraction (PXRD), energy-dispersive X-ray analysis (EDX), scanning electron microscopy (SEM) and transmission electron microscopy (TEM). According to TEM images, the size of the...

Ex-situ reductive dechlorination of carbon tetrachloride (CT) by iron sulfide in a batch reactor was characterized in this study. Reactor scaled-up by 3.5 L was used to investigate the effect of reductant concentration on removal efficiency and process optimization for ex-situ degradation. The experiment was conducted by using both liquid-phase and gas-phase volume at pH 8.5 in anaerobic condit...

The reactivity and removal kinetics of arsenite treated with single and mixed mineral systems of kaolinite, montmorillonite and goethite injected with iron sulfide under sulfidicanoxic conditions has been investigated. Using empirical models derived from Freundlich isotherm model, injection of sulfidic-anoxic solution of iron sulfide onto the mixed mineral systems enhanced proton coefficient of...

Increases in S-nitrosylation and inactivation of the neuroprotective ubiquitin E3 ligase, parkin, in the brains of patients with Parkinson's disease are thought to be pathogenic and suggest a possible mechanism linking parkin to sporadic Parkinson's disease. Here we demonstrate that physiologic modification of parkin by hydrogen sulfide, termed sulfhydration, enhances its catalytic activity. Su...

Two-level controllers for dissolved oxygen reference trajectory tracking for activated sludge processes is proposed and investigated. Both the nutrient and the phosphorous removal from a wastewater by its biological treatment using an activated sludge technology are considered. Typically, an aeration system itself is a complicated hybrid nonlinear dynamical system with faster dynamics compared ...

Submerged attached growth bioreactors (SAGBs) were operated at 20 °C for 30 weeks in smart-aerated, partial nitritation ANAMMOX mode and in a timer-controlled, cyclic aeration mode. The smart-aerated SAGBs removed 48-53% of total nitrogen (TN) compared to 45% for SAGBs with timed aeration. Low dissolved oxygen concentrations and cyclic pH patterns in the smart-aerated SAGBs suggested conditions...

The lugworm Arenicola marina inhabits marine sediments in which sulfide concentrations can reach up to 2 mM. Although sulfide is a potent toxin for humans and most animals, because it inhibits mitochondrial cytochrome c oxidase at micromolar concentrations, A. marina can use electrons from sulfide for mitochondrial ATP production. In bacteria, electron transfer from sulfide to quinone is cataly...

The discharge rate of coarse powders (mean particle size >500 pm) from bunkers without aeration can be described by both empirical relations and theoretical models. In the case of small particles the discharge rate is largely overestimated. As the powder dilates during flow a negative pressure gradient develops near the hopper outlet, inducing an air flow into the hopper. This extra drag force ...