Search results for "hydrogen sulfide"

Nylon-Supported Plasmonic Assay Based on the Aggregation of Silver Nanoparticles: In Situ Determination of Hydrogen Sulfide-like Compounds in Breath …

2019

A procedure for supporting silver nanoparticles (AgNPs) on nylon is proposed. Besides, the membrane has been developed as a solid-phase colorimetric plasmonic sensor for volatile sulfide compounds (VSCs) like H2S, CH3SH, and (CH3)2S. AgNP behavior in the membrane has been studied by UV-vis diffuse reflectance spectrometry, Raman spectrometry, High-resolution transmission electron microscopy (HR-TEM), and Scanning electron microscopy (SEM). The sensor responded by changing its color from yellow in absence of VSCs to several orange/brown colors in the function of VSC concentration as occurs in solution; an increase in the hydrodynamic diameter, estimated by both asymmetrical flow field-flow f…

Composés métallocèniques chalcogènés. Action des dihydrures de zirconocène et de hafnocène sur le soufre, le sélénium et le tellure

1989

Resume Dimeric zirconocene and hafnocene dihydrides [(η 5 -RC 5 H 4 ) 2 M(H)(μ-H)] 2 (M = Zr, Hf) react with grey selenium or tellurium to afford the known four-membered bimetallacyclic compounds [(η 5 -RC 5 H 4 ) 2 M(μ-E)] 2 (E = Se, Te) as the sole organometallic products. In the case of sulfur the first step of the reaction is shown to involve the insertion of a chalcogen atom into the metal-hydrogen bonds to give the bis-hydrogenosulfide (η 5 -t-BuC 5 H 4 ) 2 M(SH) 2 (M = Zr, Hf), which reacts either with the starting dihydride to give [(η 5 -t-BuC 5 H 4 ) 2 M(μ-S)] 2 or with the unchanged sulfur to afford the metallacyclohexasulfane (η 5 -t-BuC 5 H 4 ) 2 MS 5 and hydrogen sulfide. Thes…

Nanocrystalline ZnCO3—A novel sorbent for low-temperature removal of H2S

2013

Abstract The reactivity of a nanocrystalline ZnCO 3 toward H 2 S (0.2 vol% in N 2 /H 2 mixture) at 140–180 °C was characterized by thermal gravimetric analysis and by breakthrough curves measurements. We have found that under used conditions transformation of ZnCO 3 into ZnS is complete and the rate determining step of the sulfidation is the surface reaction. Such behavior is in strike contrast with that of ZnO whose sulfidation is severely limited by diffusion. The higher reactivity of ZnCO 3 in comparison with ZnO is attributed to the different microstructure of ZnS layer formed in these materials after a partial sulfidation. As in ZnO–ZnS transformation the molar volume increases (from 1…

Increased sulfate availability in saline water promotes hydrogen sulfide production in fish organic waste

2020

The risk of hydrogen sulfide (H2S) production can be a challenge in marine land-based recirculating aquaculture systems (RAS). Hydrogen sulfide is a toxic gas that can cause massive fish mortality even at low concentrations, and in addition, serious odour problems in the surroundings. It is a bacterial by-product originating from the degradation of organic matter in sulfur-rich waters such as marine waters. In order to hinder H2S production in marine land-based RAS, more information on the H2S production conditions and the associated microbiology is needed. In this study, the production of H2S from rainbow trout (Oncorhynchus mykiss) organic waste was examined using a novel H2S measurement …

Biogas Cleaning by Hydrogen Sulfide Scrubbing and Bio-oxidation of Captured Sulfides

2015

Hydrogen sulfide and partially carbon dioxide can be absorbed into alkaline washing liquid with nitrates for upgrading a quality of biogas. Sulfides captured into the washing liquid are consequently biologically oxidized in an anoxic bioreactor by autotrophic denitrifying bacteria. Nitrates in the washing liquid serve as electron acceptors for sulfide bio-oxidation. Washing of hydrogen sulfide from biogas was examined in a lab-scale countercurrent scrubber that was packed with plastic carriers and operated at different biogas and washing liquid flows. The hydrogen sulfide concentration in treated biogas was investigated in the range from 3 to 12.3 g m–3. The influence of the hydrogen sulfid…

Explosion limits in hydrogen sulfide/air mixtures Granice wybuchowo�ci mieszanin siarkowodoru z powietrzem

2015

H2S fluxes from Mt. Etna, Stromboli, and Vulcano (Italy) and implications for the sulfur budget at volcanoes

2005

Abstract We present here new measurements of sulfur dioxide and hydrogen sulfide emissions from Vulcano, Etna, and Stromboli (Italy), made by direct sampling at vents and by filter pack and ultraviolet spectroscopy in downwind plumes. Measurements at the F0 and FA fumaroles on Vulcano yielded SO 2 /H 2 S molar ratios of ≈0.38 and ≈1.4, respectively, from which we estimate an H 2 S flux of 6 to 9 t · d −1 for the summit crater. For Mt. Etna and Stromboli, we found SO 2 /H 2 S molar ratios of ≈20 and ≈15, respectively, which combined with SO 2 flux measurements, suggest H 2 S emission rates of 50 to 113 t · d −1 and 4 to 8 t · d −1 , respectively. We observe that “source” and plume SO 2 /H 2 …

Increased sulfate availability in saline water promotes hydrogen sulfide production in fish organic waste

2020

The risk of hydrogen sulfide (H2S) production can be a challenge in marine land-based recirculating aquaculture systems (RAS). Hydrogen sulfide is a toxic gas that can cause massive fish mortality even at low concentrations, and in addition, serious odour problems in the surroundings. It is a bacterial by-product originating from the degradation of organic matter in sulfur-rich waters such as marine waters. In order to hinder H2S production in marine land-based RAS, more information on the H2S production conditions and the associated microbiology is needed. In this study, the production of H2S from rainbow trout (Oncorhynchus mykiss) organic waste was examined using a novel H2S measurement …