Introducing the emission process of hydrogen sulfide to a sewer process model (WATS)

2003 ◽  
Vol 47 (4) ◽  
pp. 85-92 ◽  
Author(s):  
C. Yongsiri ◽  
T. Hvitved-Jacobsen ◽  
J. Vollertsen ◽  
N. Tanaka
Keyword(s):  
Hydrogen Sulfide ◽  
Process Model ◽  
Molecular Form ◽  
Engineering Application ◽  
Sulfur Cycle ◽  
Extended Model ◽  
Water Interface ◽  
Emission Process ◽  
Air Water Interface ◽  
Sewer Networks

Emission of hydrogen sulfide in sewer networks results in odor, health and corrosion problems. These problems generally occur when wastewater is transported under anaerobic and turbulent conditions. Studies on integrated aerobic/anaerobic processes in sewers have led to a conceptual sewer process model, WATS (Wastewater Aerobic/anaerobic Transformations in Sewers). The WATS model accounts for the carbon cycle, reaeration and sulfide formation. However, to handle odor, health and corrosion problems more efficiently, other aspects of the sulfur cycle need to be included. Emphasis in this study is on an extension of the WATS model in terms of hydrogen sulfide emission. A fundamental concept of this extended model is related to emission of the molecular form of hydrogen sulfide and thereby to pH of wastewater. An engineering application of the extended WATS model includes different scenarios of sewer performance concerning hydrogen sulfide emission under dissolved oxygen-limited conditions. By applying the extended WATS model, users can more realistically cope with the fate of hydrogen sulfide. Consequently, when dealing with the sulfur cycle, users need no longer be restricted to the sulfide formation process but can also take transfer of hydrogen sulfide across the air-water interface into account.

Introducing the emission process of hydrogen sulfide to a sewer process model (WATS)

2003 ◽  
Vol 47 (12) ◽  
pp. 319-320 ◽  
Author(s):  
C. Yongsiri ◽  
T. Hvitved-Jacobsen ◽  
J. Vollertsen ◽  
N. Tanaka
Keyword(s):  
Hydrogen Sulfide ◽  
Process Model ◽  
Emission Process

Hydrogen sulfide emission in sewer networks: a two-phase modeling approach to the sulfur cycle

2004 ◽  
Vol 50 (4) ◽  
pp. 161-168 ◽  
Author(s):  
C. Yongsiri ◽  
J. Vollertsen ◽  
T. Hvitved-Jacobsen
Keyword(s):  
Mass Transfer ◽  
Hydrogen Sulfide ◽  
Health Risk ◽  
Water Mass ◽  
Sulfur Cycle ◽  
Water Phase ◽  
Emission Scenarios ◽  
Two Phase ◽  
Potential Problems ◽  
Sewer Networks

Wherever transport of anaerobic wastewater occurs, potential problems associated with hydrogen sulfide in relation to odor nuisance, health risk and corrosion exist. Improved understanding of prediction of hydrogen sulfide emission into the sewer atmosphere is needed for better evaluation of such problems in sewer networks. A two-phase model for emission of hydrogen sulfide along stretches of gravity sewers is presented to estimate the occurrence of both sulfide in the water phase and hydrogen sulfide in the sewer atmosphere. The model takes into account air-water mass transfer of hydrogen sulfide and interactions with other processes in the sulfur cycle. Various emission scenarios are simulated to illustrate the release characteristics of hydrogen sulfide.

A review of sulfide emissions in sewer networks: overall approach and systemic modelling

2015 ◽  
Vol 73 (6) ◽  
pp. 1231-1242 ◽  
Author(s):  
Lucie Carrera ◽  
Fanny Springer ◽  
Gislain Lipeme-Kouyi ◽  
Pierre Buffiere
Keyword(s):  
Hydrogen Sulfide ◽  
Emission Process ◽  
The Public ◽  
Hydrogen Sulfide Production ◽  
Emission Models ◽  
Simple Systems ◽  
Physical Phenomena ◽  
Sewer Networks ◽  
Modelling Approach ◽  
Transfer Models

The problems related to hydrogen sulfide in terms of deterioration of sewer networks, toxicity and odor nuisance have become very clear to the network stakeholders and the public. The hydraulic and (bio)chemical phenomena and parameters controlling sulfide formation, emission and their incidences in sewer networks are very complex. Recent research studies have been developed in gravity and pressure sewers and some transfer models have been published. Nevertheless, the models do not take into account all the physical phenomena influencing the emission process. After summing up the main scientific knowledge concerning the production, oxidation, transfer and emission processes, the present review includes: (i) a synthetic analysis of sulfide and hydrogen sulfide emission models in sewer networks, (ii) an estimation of their limit, (iii) perspectives to improve the modelling approach. It shows that sulfide formation and uptake models still need refinements especially for some phenomena such as liquid to gas mass transfer. Transfer models that have been published so far are purposely simplified and valid for simple systems. More efforts have to be undertaken in order to better understand the mechanisms and the dynamics of hydrogen sulfide production and emission in real conditions.

Simulation of sulfide buildup in wastewater and atmosphere of sewer networks

2005 ◽  
Vol 52 (3) ◽  
pp. 201-208 ◽  
Author(s):  
A.H. Nielsen ◽  
C. Yongsiri ◽  
T. Hvitved-Jacobsen ◽  
J. Vollertsen
Keyword(s):  
Hydrogen Sulfide ◽  
Sulfide Oxidation ◽  
Sulfur Cycle ◽  
Model Concept ◽  
Concrete Corrosion ◽  
Sulfide Production ◽  
Oxidation Of Hydrogen ◽  
Sulfide Precipitation ◽  
Further Development ◽  
Sewer Networks

A model concept for prediction of sulfide buildup in sewer networks is presented. The model concept is an extension to – and a further development of – the WATS model (Wastewater Aerobic-anaerobic Transformations in Sewers), which has been developed by Hvitved-Jacobsen and co-workers at Aalborg University. In addition to the sulfur cycle, the WATS model simulates changes in dissolved oxygen and carbon fractions of different biodegradability. The sulfur cycle was introduced via six processes: 1. sulfide production taking place in the biofilm covering the permanently wetted sewer walls; 2. biological sulfide oxidation in the permanently wetted biofilm; 3. chemical and biological sulfide oxidation in the water phase; 4. sulfide precipitation with metals present in the wastewater; 5. emission of hydrogen sulfide to the sewer atmosphere and 6. adsorption and oxidation of hydrogen sulfide on the moist sewer walls where concrete corrosion may take place.

scholarly journals Criegee intermediate-hydrogen sulfide chemistry at the air/water interface

2017 ◽  
Vol 8 (8) ◽  
pp. 5385-5391 ◽  
Author(s):  
Manoj Kumar ◽  
Jie Zhong ◽  
Joseph S. Francisco ◽  
Xiao C. Zeng
Keyword(s):  
Hydrogen Sulfide ◽  
Molecular Dynamic ◽  
Molecular Dynamic Simulations ◽  
Water Interface ◽  
Dynamic Simulations ◽  
Air Water Interface

We carry out Born–Oppenheimer molecular dynamic simulations to show that the reaction between the smallest Criegee intermediate, CH2OO, and hydrogen sulfide (H2S) at the air/water interface can be observed within few picoseconds.

Sampling and analysis of the air-water interface with SEM and EDS of microlayers

1989 ◽  
Vol 47 ◽  
pp. 1004-1005
Author(s):  
Randall W. Smith ◽  
John Dash
Keyword(s):  
Heavy Metals ◽  
Surface Microlayer ◽  
Surface Films ◽  
Water Interface ◽  
Physical Processes ◽  
Infrared Spectroscopic Analysis ◽  
Eds Analysis ◽  
Air Water Interface ◽  
Significant Area ◽  
Bulk Chemical

The structure of the air-water interface forms a boundary layer that involves biological ,chemical geological and physical processes in its formation. Freshwater and sea surface microlayers form at the air-water interface and include a diverse assemblage of organic matter, detritus, microorganisms, plankton and heavy metals. The sampling of microlayers and the examination of components is presently a significant area of study because of the input of anthropogenic materials and their accumulation at the air-water interface. The neustonic organisms present in this environment may be sensitive to the toxic components of these inputs. Hardy reports that over 20 different methods have been developed for sampling of microlayers, primarily for bulk chemical analysis. We report here the examination of microlayer films for the documentation of structure and composition.Baier and Gucinski reported the use of Langmuir-Blogett films obtained on germanium prisms for infrared spectroscopic analysis (IR-ATR) of components. The sampling of microlayers has been done by collecting fi1ms on glass plates and teflon drums, We found that microlayers could be collected on 11 mm glass cover slips by pulling a Langmuir-Blogett film from a surface microlayer. Comparative collections were made on methylcel1ulose filter pads. The films could be air-dried or preserved in Lugol's Iodine Several slicks or surface films were sampled in September, 1987 in Chesapeake Bay, Maryland and in August, 1988 in Sequim Bay, Washington, For glass coverslips the films were air-dried, mounted on SEM pegs, ringed with colloidal silver, and sputter coated with Au-Pd, The Langmuir-Blogett film technique maintained the structure of the microlayer intact for examination, SEM observation and EDS analysis were then used to determine organisms and relative concentrations of heavy metals, using a Link AN 10000 EDS system with an ISI SS40 SEM unit. Typical heavy microlayer films are shown in Figure 3.

Temperature Dependence of the Air/Water Interface Revealed by Polarization Sensitive Sum-Frequency Generation Spectroscopy

2018 ◽  
Author(s):  
Daniel R. Moberg ◽  
Shelby C. Straight ◽  
Francesco Paesani
Keyword(s):  
Temperature Dependence ◽  
Low Frequency ◽  
Potential Energy Function ◽  
Md Simulations ◽  
Sum Frequency Generation ◽  
Water Molecules ◽  
Water Interface ◽  
Sum Frequency ◽  
Air Water Interface ◽  
Frequency Generation

<div> <div> <div> <p>The temperature dependence of the vibrational sum-frequency generation (vSFG) spectra of the the air/water interface is investigated using many-body molecular dynamics (MB-MD) simulations performed with the MB-pol potential energy function. The total vSFG spectra calculated for different polarization combinations are then analyzed in terms of molecular auto-correlation and cross-correlation contributions. To provide molecular-level insights into interfacial hydrogen-bonding topologies, which give rise to specific spectroscopic features, the vSFG spectra are further investigated by separating contributions associated with water molecules donating 0, 1, or 2 hydrogen bonds to neighboring water molecules. This analysis suggests that the low frequency shoulder of the free OH peak which appears at ∼3600 cm−1 is primarily due to intermolecular couplings between both singly and doubly hydrogen-bonded molecules. </p> </div> </div> </div>

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