Model-Driven Strategies for Sulfide Control in a Regional Wastewater System Receiving Tannery Effluents in Portugal

Water ◽  
2021 ◽  
Vol 13 (20) ◽  
pp. 2838
Author(s):  
Rita Ventura Matos ◽  
Manuel Peixeiro ◽  
Filipa Ferreira ◽  
José Saldanha Matos
Keyword(s):  
Industrial Effluents ◽  
Field Work ◽  
Field Studies ◽  
Pilot Scale ◽  
Tannery Effluents ◽  
Considerable Uncertainty ◽  
Model Driven ◽  
Sewer Systems ◽  
Iron Salts ◽  
Systems Modelling

Ageing infrastructure are a concern for many wastewater utilities. This is accentuated with the presence of hydrogen sulfide within the sewer headspace, known to induce concrete corrosion, toxicity and odours. Some industrial effluents contain significant sulfide concentrations, however most field studies in the literature refer to domestic networks, or lab/pilot scale sulfide abatement strategies for varied effluents. Hence, the objectives of this work are: (1) To obtain data regarding the evolution of sulfides in a full-scale industrial sewer system in Portugal, receiving wastewater from a number of tanneries; (2) model their fate within the system and (3) experimentally evaluate sulfide precipitation with iron salts. Field work evidenced heavily sulfide loaded effluents, exceeding by far literature values for sewer systems. Modelling was carried out based on the AeroSept+ model, specifically calibrated to this type of effluent. Results showed the model was capable of reproducing the overall levels of sulfide in wastewater and H2S in the sewer headspace, while allowing insights into industrial discharges, originating a set of proposed interventions for sulfide abatement. This may be carried out by iron salts addition, in a ratio of 2.75:1, at existing monitoring stations. This approach was fundamental for an affordable performance assessment, under considerable uncertainty.

scholarly journals Willows Used for Phytoremediation Increased Organic Contaminant Concentrations in Soil Surface

2021 ◽  
Vol 11 (7) ◽  
pp. 2979
Author(s):  
Maxime Fortin Faubert ◽  
Dominic Desjardins ◽  
Mohamed Hijri ◽  
Michel Labrecque
Keyword(s):  
Soil Surface ◽  
Field Work ◽  
Field Studies ◽  
Soil Hydrology ◽  
Intensive Culture ◽  
Shrub Species ◽  
Short Rotation ◽  
Pollutant Concentrations ◽  
Polycyclic Aromatic ◽  
Made In

The Salix genus includes shrub species that are widely used in phytoremediation and various other phytotechnologies due to their advantageous characteristics, such as a high evapotranspiration (ET) rate, in particular when cultivated in short rotation intensive culture (SRIC). Observations made in past field studies suggest that ET and its impact on soil hydrology can also lead to increases in soil pollutant concentrations near shrubs. To investigate this, sections of a mature willow plantation (seven years old) were cut to eliminate transpiration (Cut treatment). Soil concentrations of polychlorinated biphenyls (PCBs), aliphatic compounds C10–C50, polycyclic aromatic hydrocarbons (PAHs) and five trace elements (Cd, Cr, Cu, Ni and Zn) were compared between the Cut and the uncut plots (Salix miyabeana ‘SX61’). Over 24 months, the results clearly show that removal of the willow shrubs limited the contaminants’ increase in the soil surface, as observed for C10–C50 and of 10 PAHs under the Salix treatment. This finding strongly reinforces a hypothesis that SRIC of willows may facilitate the migration of contaminants towards their roots, thus increasing their concentration in the surrounding soil. Such a “pumping effect” in a high-density willow crop is a prominent characteristic specific to field studies that can lead to counterintuitive results. Although apparent increases of contaminant concentrations contradict the purification benefits usually pursued in phytoremediation, the possibility of active phytoextraction and rhizodegradation is not excluded. Moreover, increases of pollutant concentrations under shrubs following migration suggest that decreases would consequently occur at the source points. Some reflections on interpreting field work results are provided.

scholarly journals Hydrogeological study of mangrove areas around Guanabara Bay, Rio de Janeiro, Brazil

2003 ◽  
Vol 26 ◽  
pp. 92-100
Author(s):  
Gerson Cardoso da Silva Júnior ◽  
Carlos Eduardo Braga ◽  
Ingrid De Carvalho Lage
Keyword(s):  
Rio De Janeiro ◽  
Research Effort ◽  
Industrial Effluents ◽  
Field Work ◽  
Mangrove Ecosystem ◽  
Analytical Models ◽  
Guanabara Bay ◽  
Petrochemical Complex ◽  
Hydrogeological Study ◽  
Hydrogeological Studies

The study area covers part of the mangrove belt located around Guanabara Bay, Rio de Janeiro, Brazil. Representing a continental-marine transition, the mangrove ecosystem is very susceptible to environmental variations and impacts. The vegetation cover plays an important role in prevention of erosion and contamination processes in those areas. An ongoing extensive research effort in the Petrochemical Complex of Duque de Caxias, Rio de Janeiro State, Brazil, focuses on the man-induced changes in the physical environment (soils, groundwater flow system, type and volumes of contaminants, geochemical aspects) and the consequences on the neighboring mangrove ecosystem. This article describes the importance of hydrogeological studies in mangrove areas as part of an appropriate environmental assessment, taking as an example an industrial dumping area located in that Petrochemical Complex. Field work included extensive drilling and sampling to obtain basic geological and hydrogeological parameters and data in the pilot area, such as hydraulic conductivity and piezometric heads; emphasizing the tracking of possible contamination by industrial effluents and the marine influence; validation of the conceptual model with mathematical models (numerical and analytical models) was carried out. Results show the great importance of well conducted and detailed hydrogeological studies to properly address environmental problems caused by industrial plants in mangrove areas.

The Collapse of Thermal Contraction

1999 ◽  
Author(s):  
Naomi Oreskes
Keyword(s):  
Field Work ◽  
Field Studies ◽  
Lower Limbs ◽  
Swiss Alps ◽  
Late Nineteenth Century ◽  
Thermal Contraction ◽  
Thrust Faults ◽  
The Alps ◽  
Academy Of Sciences ◽  
Contraction Theory

In 1901, Karl Zittel, president of the Bavarian Royal Academy of Sciences, declared that “Suess has secured almost general recognition for the contraction theory” of mountain-building. This was wishful thinking. Suess’s Das Antlitz der Erde was indeed an influential work, but by the time Suess finished the final volume (1904), the thermal contraction theory was under serious attack. Problems were evident from three different but equally important quarters. The most obvious problem for contraction theory arose from field studies of mountains themselves. As early as the 1840s, it had been recognized that the Swiss Alps contained large slabs of rock that appeared to have been transported laterally over enormous distances. These slabs consisted of nearly flat-lying rocks that might be construed as undisplaced, except that they lay on top of younger rocks. In the late nineteenth century, several prominent geologists, most notably Albert Heim (1849 –1937), undertook extensive field work in the Alps to attempt to resolve their structure. Heim’s detailed field work, beautiful maps, and elegant prose convinced geological colleagues that the Alpine strata had been displaced horizontally over enormous distances. In some cases, the rocks had been accordioned so tightly that layers that previously extended horizontally for hundreds of kilometers were now reduced to distances of a few kilometers. But in even more startling cases, the rocks were scarcely folded at all, as if huge slabs of rocks had been simply lifted up from one area of the crust and laid down in another. Heim interpreted the slabs of displaced rock in his own Glarus district as a huge double fold with missing lower limbs, but in 1884 the French geologist Marcel Bertrand (1847–1907) argued that these displacements were not folds but faults. Large segments of the Alps were the result of huge faults that had thrust strata from south to north, over and on top of younger rocks. August Rothpletz (1853–1918), an Austrian geologist, realized that the Alpine thrust faults were similar to those that had been earlier described by the Rogers brothers in the Appalachians. By the late 1880s, thrust faults had been mapped in detail in North America, Scotland, and Scandinavia.

Impact of volcanic halogens on the ozone layer and climate, a look to the past to highlight the present

2020 ◽  
Author(s):  
Hélène Balcone-Boissard ◽  
Thiébaut D'Augustin ◽  
Georges Boudon ◽  
Slimane Bekki ◽  
Magali Bonifacie ◽  
...  
Keyword(s):  
Volcanic Eruptions ◽  
Field Work ◽  
Field Studies ◽  
Global Scale ◽  
Ozone Layer ◽  
Volatile Species ◽  
Magma Supply ◽  
Global Impacts ◽  
Almost All ◽  
The Impact

<p>Explosive eruptions of the Plinian type inject large amounts of particles (pumice, ash, aerosols) and volatile species into the atmosphere. They result from the rapid discharge of a magma chamber and involve large volumes of magma (from a km<sup>3</sup> to hundreds of km<sup>3</sup>). Such eruptions correspond to a rapid ascent of magma in the conduit driven by the exsolution of volatile species. If the magma supply is continuous, this jet produces a convective eruptive column that can reach tens of km in height and transports gas and particles (pumice, ash, aerosols) directly into the stratosphere. Depending on the latitude of the volcano, the volume of implied magma, the height of the eruptive plume and the composition of the released gaseous and particulate mixture, these events can strongly affect the environment at the local or even at a global scale. Almost all studies on global impacts of volcanic eruptions have largely focused on the sulfur component. Volcanoes are also responsible for the emission of halogens which have a crucial impact on the ozone layer and therefore the climate.</p><p>The objective of our project is to revisit the issue of the impact of volcanism on the atmosphere and climate by considering not only the sulfur component but also the halogen component. We will provide field work-based constraints on the strength of halogen (Cl and Br) emissions and on degassing processes for key eruptions, we will characterise the dynamics of volcanic plumes, notably the vertical distribution of emissions and we will explore and quantify the respective impacts of sulfur and halogen emissions on the ozone layer and climate.</p><p> </p><p>Here we will shed light on the methodology that will combine field campaign, laboratory analysis of collected samples and a hierarchy of modelling tools to study. We use an approach combining field studies, petrological characterization, geochemical measurements including isotopic data, estimation of the volume of involved magma and the height of injection of gases and particles by modelling the eruptive plume dynamic and numerical simulation of the impacts at the plume scale and at the global scale.  The first halogen budget will also be presented.</p>

Understanding the spatial formation and accumulation of fats, oils and grease deposits in the sewer collection system

2013 ◽  
Vol 68 (8) ◽  
pp. 1830-1836 ◽  
Author(s):  
Christopher Cyril Sandeep Dominic ◽  
Megan Szakasits ◽  
Lisa O. Dean ◽  
Joel J. Ducoste
Keyword(s):  
Fatty Acids ◽  
Fatty Acid ◽  
Unsaturated Fatty Acids ◽  
Saturated Fatty Acids ◽  
Pilot Scale ◽  
Collection System ◽  
Neutral Ph ◽  
Sanitary Sewer ◽  
Sewer Systems ◽  
Oils And Grease

Sanitary sewer overflows are caused by the accumulation of insoluble calcium salts of fatty acids, which are formed by the reaction between fats, oils and grease (FOG) and calcium found in wastewaters. Different sewer structural configurations (i.e., manholes, pipes, wet wells), which vary spatially, along with other obstructions (roots intrusion) and pipe deformations (pipe sags), may influence the detrimental buildup of FOG deposits. The purpose of this study was to quantify the spatial variation in FOG deposit formation and accumulation in a pilot-scale sewer collection system. The pilot system contained straight pipes, manholes, roots intrusion, and a pipe sag. Calcium and oil were injected into the system and operated at alkaline (pH = 10) and neutral (pH = 7) pH conditions. Results showed that solid accumulations were slightly higher at neutral pH. Fourier transform infrared (FTIR) analysis on the solids samples confirmed that the solids were indeed calcium-based fatty acid salts. However, the fatty acid profiles of the solids deviated from the profile found from FOG deposits in sewer systems, which were primarily saturated fatty acids. These results confirm the work done previously by researchers and suggest an alternative fate of unsaturated fatty acids that does not lead to their incorporation in FOG deposits in full-scale sewer systems.

Field Studies of DCMU-Enhanced Fluorescence as an Index of in situ Phytoplankton Photosynthetic Activity

1980 ◽  
Vol 37 (6) ◽  
pp. 1028-1031 ◽  
Author(s):  
Suzanne Roy ◽  
Louis Legendre
Keyword(s):  
Photosynthetic Activity ◽  
Field Work ◽  
Field Studies ◽  
Gulf Of Guinea ◽  
Lawrence Estuary ◽  
Technical Problems ◽  
Lower Light ◽  
St Lawrence Estuary ◽  
Composition Changes

Comparison between the increase in fluorescence caused by DCMU (FD/FN: ratio of DCMU-enhanced to normal fluorescence) and the specific photosynthetic rate (P/B: photosynthetic activity per unit chlorophyll a) in the St. Lawrence Estuary showed that no overall correlation could be established between P/B and FD/FN, although there were significant correlations between these two variables on short transects. This reflected perhaps environmental and species composition changes. FD/FN vertical profiles in the Gulf of St. Lawrence and the Gulf of Guinea showed a characteristic increase with depth, as seen in laboratory cultures with a decrease in light intensity. This could be related to photosynthetic efficiency which is known to increase at lower light intensities. Technical problems involving the use of FD/FN as an estimator of P/B are also discussed. Further investigations are required before this fluorescence technique can be used regularly in field work to estimate photosynthetic activity.Key words: DCMU, fluorescence, photosynthesis, phytoplankton, St. Lawrence Estuary, Gulf of Guinea

Pathogenic viruses in drinking-water biofilms: a public health risk?

Biofilms ◽  
2005 ◽  
Vol 2 (2) ◽  
pp. 105-117 ◽  
Author(s):  
S. Skraber ◽  
J. Schijven ◽  
C. Gantzer ◽  
A. M. de Roda Husman
Keyword(s):  
Drinking Water ◽  
Health Risk ◽  
Distribution Systems ◽  
Water Distribution ◽  
Tap Water ◽  
Field Studies ◽  
Pilot Scale ◽  
Drinking Water Distribution Systems ◽  
Virus Attachment ◽  
Pathogenic Viruses

Biofilms in drinking-water distribution systems may accumulate human pathogenic viruses. Viruses that attach to biofilm are removed from the water phase improving the water quality. However, if released in slough, it may still present a risk of infection. This review describes the available data on the presence of pathogenic viruses in drinking-water biofilms. First, biofilms of distribution systems potentially contribute to viral contamination of tap water only if infectious viruses are present initially in the water, which has been shown in several recent studies. However, only one out of three field studies showed the presence of infectious enteroviruses in natural biofilms from drinking-water networks. The presence of pathogenic viruses in biofilms points to the ability of these viruses to attach to biofilms. This has also been shown in pilot-scale studies in which bacteriophages and vaccine poliovirus strains were spiked into water and could be eluted from artificial biofilms. Reported attachment rates vary greatly and may depend on many factors such as the biofilm characteristics, the virus strain and the efficiency of viral recovery from biofilms. One study reported biphasic viral inactivation in biofilms with rapid initial inactivation followed by slow inactivation, implying that some of the attached viruses are able to remain infectious for a longer time. In several laboratory experiments, virus attachment to biofilms has been reported under various conditions; however, although detachment of sloughs in distribution systems has been observed, the presence of viruses in these sloughs was not studied. Here, we discuss the possible presence of infectious pathogenic viruses in sloughs; the extent to which these will pose a health risk remains to be investigated.

scholarly journals Calving Ice Walls

1989 ◽  
Vol 12 ◽  
pp. 74-80 ◽  
Author(s):  
T. Hughes
Keyword(s):  
Shear Bands ◽  
Ice Sheets ◽  
Field Work ◽  
Field Studies ◽  
Line Field ◽  
Dry Land ◽  
Water Trough ◽  
Ablation Mechanism ◽  
Shear Rupture ◽  
Made In

Calving ice walls are an important ablation mechanism for deglaciation of calving bays occupied by temperate tide-water glaciers and polar marine ice sheets. Dangers inherent in calving bays have precluded detailed field studies of these calving ice walls. However, calving ice walls also exist in sub-polar glaciers terminating on dry land, and an opportunity for detailed field work was afforded by the 12 August 1970 volcanic eruption on Deception Island (63.0°S, 60.6°W), where thawing of a surface blanket of ice-cemented ash produced solifluction ramps that made parts of the ice wall accessible. Measurements made in a melt-water trough incised into the ice wall, and in four tunnels cut into the ice wall, revealed numerous shear bands that rose almost vertically and curved forward. Shear offset increased upward and was greatest in shear bands that intersected the tips of ring-fault crevasses on the up-slope side of the ice wall. Near the base of the ice wall, other shear bands, possibly related to the slip-line field, intersected the ice wall at about 45°. Ice slabs separated by ring faults calved straight down as a result of shear rupture along these two sets of shear bands. Calving dynamics were analyzed and generalized for ice walls grounded in water.

scholarly journals Industrial Automation in Unit Operations Labs

2015 ◽  
Author(s):  
Konstantinos Apostolou ◽  
Ishwar Singh
Keyword(s):  
Chemical Engineering ◽  
Field Work ◽  
Pilot Scale ◽  
Unit Operation ◽  
Sensors And Actuators ◽  
Industrial Automation ◽  
Control Loops ◽  
Unit Operations ◽  
Processing Facility ◽  
Set Up

Chemical engineering unit operation labsdo an excellent job of integrating the whole curriculumand exposing students to pilot-scale systems. Where theyare often lacking, though, is the exposure to and use ofreal-life industrial automation by the future graduates. Aunit operation lab that has been automated usingindustrial level paradigms and equipment is the focus ofthis paper. A partnership with a global automationmanufacturer (Emerson) was established and the lab wasretrofitted using industrial sensors and actuators, aDistributed Control System (DeltaV DCS), industrialnetworks (FOUNDATION Fieldbus and AS-i), HumanMachine Interface (HMI) screens, and systemredundancy. The details of the automation along with itsuse through the lab curriculum will be discussed. Thiscross-curricular approach benefits students as, throughthe regular unit operation labs, they become familiar withkey elements of an automated set-up, understand the needfor it and its limitations, see control loops in action,communicate to the units through the HMI, and use theHMI to recover historical data on the processes. The labis a meso-scale of a processing facility and preparesstudents for field work after graduation. At the sametime, the traditional exposure to “manually operated”sensors and final elements is maintained as some of theunits have not been converted to fully automated systems

scholarly journals Estimation of Some Physico-Chemical Parameters of Tannery Effluents to Surrounding Environment (A Yemeni Case Study)

2021 ◽  
Vol 3 (30) ◽  
pp. 96-110
Author(s):  
Adel A. M. Saeed ◽  
◽  
Nasser M. N. Masood ◽  
Ali N. A. Al-Kumi ◽  
◽  
...  
Keyword(s):  
Negative Impact ◽  
Industrial Effluent ◽  
Health And Safety ◽  
Oxygen Demand ◽  
Negative Ions ◽  
Industrial Effluents ◽  
Chemical Parameters ◽  
Tannery Effluents ◽  
Physico Chemical ◽  
The Government

Water pollution caused by leather industrial effluent discharges has become a troublesome phenomenon due to its negative impact on environmental health and safety. In this paper, the wastewater in the vicinity of Lawdar tannery areas was assessed in two years from October 2019 to June 2021 to determine physico-chemical parameters of industrial effluents of Lawdar tannery at four different area points. Tannery effluents were collected and all samples were analyzed in the laboratory and rated as no freshwater with parameters such as acidity and basicity, temperature, electrical conductivity, total dissolved solids, total suspended solids, chemical oxygen demand, biological oxygen demand, color, turbidity, hardness, alkalinity, and several positive and negative ions. The investigation showed that all physico-chemical parameters were higher than the standard disposal limits of discharged water quality. The findings of this research will assist the government and tanneries in the treatment of wastewater before discharging to the environment and monitoring the dump sites with regards to disposal arrangement of the tannery effluents and environmental assessment.

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