Release of hydrogen sulfide in a sewer system under intermittent flow conditions: the Ericeira case study, in Portugal

2017 ◽  
Vol 75 (7) ◽  
pp. 1702-1711 ◽  
Author(s):  
Natércia Matias ◽  
Rita Ventura Matos ◽  
Filipa Ferreira ◽  
Jes Vollertsen ◽  
José Saldanha Matos
Keyword(s):  
Hydrogen Sulfide ◽  
Corrosion Damage ◽  
Intermittent Flow ◽  
Rapid Decline ◽  
Sewer System ◽  
Phase Measurements ◽  
Wastewater Systems ◽  
Dissolved Sulfide ◽  
Intensive Sampling

The presence and fate of hydrogen sulfide in wastewater systems were studied in two stretches of an intercepting sewer system located in a coastal village, in Portugal. A range of hydraulic parameters were obtained and liquid and gas phase measurements were carried out, both continuously and through intensive sampling campaigns. Upstream, where flow rates were relatively low, dissolved sulfide concentrations around 12 mg S L−1 and hydrogen sulfide gas concentrations above 250 ppm were observed, along with limited corrosion damage. It is believed this is due to the low relative humidity detected along the atmosphere of the studied sewer system. Downstream, gas concentrations were always below 40 ppm. Despite that, high signs of corrosion were detected, particularly in manholes with drop structures. It is thought that condensation of spray produced by the fall is the main cause of the phenomenon. Another relevant observation was the rapid decline in dissolved sulfide contents along gravity trunk sewers following the discharge of rising mains, with loss rates as high as 40 mg S L−1 h−1. Air-flow velocities corresponded to 15–50% of wastewater flows, an observation which agrees with other authors' publications addressing relatively small pipes and moderate water flows.

scholarly journals Release of hydrogen sulfide under intermittent flow conditions – the potential of simulation models

2017 ◽  
Vol 77 (3) ◽  
pp. 777-787 ◽  
Author(s):  
Natércia Matias ◽  
Rita Matos ◽  
Filipa Ferreira ◽  
Jes Vollertsen ◽  
José Saldanha Matos
Keyword(s):  
Hydrogen Sulfide ◽  
Simulation Models ◽  
Intermittent Flow ◽  
Air Velocity ◽  
Modeling Tools ◽  
Complex Approach ◽  
Wide Range ◽  
Dissolved Sulfide ◽  
Liquid Mass Transfer ◽  
And Control

Abstract For engineering purposes it is especially useful to be able to predict and control sewer corrosion rates and odor impacts as well as to design effective measures aiming to reduce effects related to hydrogen sulfide formation and release. Doing so, it is important to use modeling tools that are capable of assessing variations of dissolved oxygen, dissolved sulfide and hydrogen sulfide gas concentrations for a wide range of environmental scenarios. Two such models were assessed: AEROSEPT, an empirical formulation, and WATS, a conceptual and more complex approach. The models were applied to evaluate the effects of transitions between pressure mains and gravity sewers in the air–liquid mass transfer of hydrogen sulfide at the Ericeira sewer system in Portugal. This network is known to have odor and corrosion problems, especially during summer. Despite the unavoidable uncertainties due to the unsteady flow rate and the quantification of air velocity and turbulence, the simulation results obtained with both models have been shown to adequately predict the overall behavior of the system.

scholarly journals No-regret selection of effective control handles for integrated urban wastewater systems management under parameter and input uncertainty

2020 ◽  
Vol 81 (8) ◽  
pp. 1749-1756 ◽  
Author(s):  
J. M. Ledergerber ◽  
T. Maruéjouls ◽  
P. A. Vanrolleghem
Keyword(s):  
Global Sensitivity Analysis ◽  
Screening Method ◽  
Real Life ◽  
Effective Control ◽  
Urban Wastewater ◽  
Sewer System ◽  
Input Uncertainty ◽  
Wastewater Systems ◽  
Selection Of

Abstract Regulatory water quality limits are extended from the wastewater resource recovery facility (WRRF) to the sewer system. It is thus necessary to properly integrate those systems for the evaluation of the overall emissions to the receiving water. The integration of the sewer system and the WRRF, however, leaves us with multiple potential options to reduce these emissions. The proposed approach builds on previous research using global sensitivity analysis (GSA) as a screening method for available control handles. It considers parameter and input uncertainty to select control handles that generate large benefits even if the model differs from reality. Results from a real-life case study indicate that the three top-rated handles are comparably effective for all considered uncertainty and variability scenarios. But the results also showed that this does not apply to lower-rated handles.

Sediment transport under dry weather conditions in a small sewer system

1998 ◽  
Vol 37 (1) ◽  
pp. 155-162
Author(s):  
Flemming Schlütter ◽  
Kjeld Schaarup-Jensen
Keyword(s):  
Sediment Transport ◽  
Field Data ◽  
Field Measurements ◽  
Weather Conditions ◽  
Sewer System ◽  
Transport Models ◽  
Sewer Systems ◽  
Combined Sewer ◽  
Initial Results

Increased knowledge of the processes which govern the transport of solids in sewers is necessary in order to develop more reliable and applicable sediment transport models for sewer systems. Proper validation of these are essential. For that purpose thorough field measurements are imperative. This paper renders initial results obtained in an ongoing case study of a Danish combined sewer system in Frejlev, a small town southwest of Aalborg, Denmark. Field data are presented concerning estimation of the sediment transport during dry weather. Finally, considerations on how to approach numerical modelling is made based on numerical simulations using MOUSE TRAP (DHI 1993).

scholarly journals The Budget as a Basis for Ecological Management of Urbanization Projects. Case Study in Seville, Spain

2021 ◽  
Vol 13 (7) ◽  
pp. 4078
Author(s):  
María Rocío Ruiz-Pérez ◽  
María Desirée Alba-Rodríguez ◽  
Cristina Rivero-Camacho ◽  
Jaime Solís-Guzmán ◽  
Madelyn Marrero
Keyword(s):  
Public Procurement ◽  
Embodied Energy ◽  
Short Term ◽  
Sewer System ◽  
Communication Services ◽  
Concrete Aggregates ◽  
The Public ◽  
Basic Services ◽  
Total Impact

Urbanization projects, understood as those supplying basic services for cities, such as drinking water, sewers, communication services, power, and lighting, are normally short-term extremely scattered actions, and it can be difficult to track their environmental impact. The present article’s main contribution is to employ the project budgets of public urbanization work to provide an instrument for environmental improvement, thereby helping public procurement, including sustainability criteria. Two urban projects in Seville, Spain are studied: the first substitutes existing services, and the second also includes gardens and playgrounds in the street margins. The methodology finds the construction elements that must be controlled in each project from the perspective of three indicators: carbon, water footprints, and embodied energy. The main impacts found are due to only four construction units: concrete, aggregates, asphalt, and ceramic pipes for the sewer system, that represent 70% or more of the total impact in all indicators studied. The public developer can focus procurement on those few elements in order to exert a lower impact and to significantly reduce the environmental burden of urbanization projects.

An application of Austrian legal requirements for CSO emissions

2011 ◽  
Vol 64 (5) ◽  
pp. 1081-1088 ◽  
Author(s):  
Manfred Kleidorfer ◽  
Wolfgang Rauch
Keyword(s):  
Model Calibration ◽  
Model Building ◽  
Treatment Plant ◽  
Cost Effective ◽  
Combined Sewer Overflows ◽  
Sewer System ◽  
Legal Requirements ◽  
Innovative Methods ◽  
Combined Sewer

The Austrian standard for designing combined sewer overflow (CSO) detention basins introduces the efficiency of the combined sewer overflows as an indicator for CSO pollution. Additionally criteria for the ambient water quality are defined, which comprehend six kinds of impacts. In this paper, the Austrian legal requirements are described and discussed by means of hydrological modelling. This is exemplified with the case study Innsbruck (Austria) including a description for model building and model calibration. Furthermore an example is shown in order to demonstrate how – in this case – the overall system performance could be improved by implementing a cost-effective rearrangement of the storage tanks already available at the inflow of the wastewater treatment plant. However, this guideline also allows more innovative methods for reducing CSO emissions as measures for better usage of storage volume or de-centralised treatment of stormwater runoff because it is based on a sewer system simulation.

scholarly journals Energy Balance in Wastewater Systems with Energy Recovery: A Portuguese Case Study

2021 ◽  
Vol 6 (10) ◽  
pp. 141
Author(s):  
Catarina Jorge ◽  
Maria do Céu Almeida ◽  
Dídia Covas
Keyword(s):  
Energy Efficiency ◽  
Energy Balance ◽  
Energy Recovery ◽  
Real Life ◽  
Wet Season ◽  
Current Case ◽  
Total Input ◽  
Wastewater Systems ◽  
Regional Reference

This paper presents and discusses the application of a novel energy balance scheme for assessing energy efficiency in wastewater systems. The energy balance is demonstrated with a Portuguese real-life case study, using mathematical modelling to estimate the different energy components and to compute two energy efficiency indices. The total inflow intrinsic energy can represent a significant amount (>95%) of the total energy used in systems mainly composed of gravity sewers. The total input energy is significantly (four-times) higher in the wet season than in the dry season, mostly due to undue inflows (e.g., direct rainfall and infiltration). The potential for energy recovery strongly depends on the available head and flow rate at the delivery point, being 0.01 kWh/m3 in the current case, with a project payback period of 4 years. The energy balance components and the respective energy efficiency indices strongly depend on the considered reference elevation. Thus, a unique regional reference elevation is recommended in the calculations.

scholarly journals Occupational inhalation injury by Hydrogen Sulfide causing multi organ failure –A case study

2019 ◽  
Vol 7 (2) ◽  
pp. 113-115 ◽  
Author(s):  
Karishma Shamarukh ◽  
- Mohammad Omar Faruq ◽  
Nasrin Jahan ◽  
Amina Sultana ◽  
Ridwan Naim Faruq
Keyword(s):  
Hydrogen Sulfide ◽  
Troponin I ◽  
Treatment Plant ◽  
Inhalation Injury ◽  
Effluent Treatment ◽  
Effluent Treatment Plant ◽  
Chest X Ray ◽  
Brain Ct Scan ◽  
Serious Injuries

Hydrogen sulfide is a notorious agent known to cause serious injuries in the occupational field. We are going to discussa case of a 20 years old male working in a effluent treatment plant in Savar, Bangladesh who accidentally entered thefume room and was exposed to the toxic gas. He lost consciousness and was brought to our care from a local hospitalafter endotracheal intubation condition. He was found in state of unconsciousness grade III on admission to our ICU.His brain CT scan revealed diffuse cerebral edema. Chest X-ray revealed finding suggestive of diffuse pneumonitis.Cardiology evaluation suggested Toxic cardiomyopathy as his high sensitive Troponin I was very high on admission (2037ng/L). Supportive care was given in the form of mechanical ventilation, antibiotics, anticonvulsant andanti-ischemic medications. Patient regained consciousness on day 10 after admission and gradually improvedclinically. By the end of the month of stay in hospital he was significantly improved. Bangladesh Crit Care J September 2019; 7(2): 113-115

scholarly journals Problems of Mechanized Tunneling In Gassy Ground Conditions a Case Study: Nousoud Water Transmission Tunnel

2014 ◽  
Vol 3 (8) ◽  
pp. 101-113
Author(s):  
Naser Tali ◽  
Gholam Reza Lashkaripour ◽  
Mohamad Ghafoori ◽  
Naser Hafezimoghadas
Keyword(s):  
Hydrogen Sulfide ◽  
Dissolved Gas ◽  
Loss Of Life ◽  
Methane Gas ◽  
Project Costs ◽  
Ground Conditions ◽  
Water Transmission ◽  
Working Efficiency ◽  
Geotechnical Studies

Current advances in science, followed by development of excavation equipments technology resulted in growth of tunnelling projects for different purposes. In spite of conducting exploratory studies prior to these projects, in some cases due to of impassable paths, the studies are limited to certain areas. Hence, during geotechnical studies, it is possible that all problems facing tunnelling not be detected. Therefore, lack of awareness of these conditions can result in a lack of proper planning and consequently lead to problems during the projects. Due to the lack of knowledge and consequently not predicting and planning the projects, drilling of the second sector of Nousoud water transmission tunnel, -26 km long- has been faced with many problems including emission of hydrogen sulfide and methane gas and drainage of high volumes of water containing dissolved gas into the tunnel, which has led to the loss of life, loss of working efficiency, as well as increased project costs. In this study, problems occurred in this project, reasons behind them will be addressed; and the solutions to these problems will be mentioned. The results of the study have shown that oil-bearing formations of the region and the immigration of gases coming from these formations have let the gas entered into the tunnel. In addition, due to the high solubility of hydrogen sulfide and methane gas in water on one hand, and hydrated formations with high permeability on the other hand, caused the influx of large quantities of water and therefore the concentration of these gases in the tunnel.

Taste and odour removal from an urban groundwater establishment – a case study

2000 ◽  
Vol 42 (1-2) ◽  
pp. 123-128 ◽  
Author(s):  
E. Ortenberg ◽  
L. Groisman ◽  
C. Rav-Acha
Keyword(s):  
Hydrogen Sulfide ◽  
Chlorine Dioxide ◽  
Urban Groundwater ◽  
Partial Solution ◽  
Deep Groundwater ◽  
Advantages And Disadvantages ◽  
Water Characteristics ◽  
Chemical Oxidants ◽  
Odour Removal

A deep groundwater well was established in a village near Tel-Aviv, in order to supply drinking water for its 30,000 inhabitants. Although all water characteristics were within the range permitted by the Israeli regulations, operators received complaints about a funny taste and a rotten-egg odour in the water. This was attributed to the presence of 0.38 mgL–1 hydrogen sulfide. Removing the odour by the usual method of aeration was impossible because of the populated surroundings. Therefore it was decided to examine chemical oxidants for taste and odour removal. A treatment with 8 mgL–1 of chlorine successfully oxidized hydrogen sulfide but the complaints continued. This was attributed to the formation of elemental sulfur, whichis converted into polysulfide that may hydrolyze to regenerate the odourous hydrogen sulfide. Treatment with 2 mgL–1 of chlorine dioxide successfully eliminates odour completely, but produces chlorite and chlorate which are above the permitted levels. A partial solution to this problem was found by a consequential treatment with 2 mgL–1 of ClO2 for 10 min. followed by 1.5 mgL–1 of chlorine (30 min.). In this case the chlorite is reduced substantially to be within the permitted level. In addition, such treatment regenerates some of the chlorine dioxide thereby increasing its residual. The odourous H2S can also be eliminated with 3 mgL–1 of ozone. Advantages and disadvantages of the above treatments are discussed.

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