scholarly journals Management of Dredging Activities in a Highly Vulnerable Site: Simulation Modelling and Monitoring Activity

2020 ◽  
Vol 8 (12) ◽  
pp. 1020
Author(s):  
Diana De Padova ◽  
Mouldi Ben Meftah ◽  
Francesca De Serio ◽  
Michele Mossa
Keyword(s):  
Southern Italy ◽  
Numerical Models ◽  
Ecological Status ◽  
Simulation Modelling ◽  
Suspended Solid ◽  
Coastal Site ◽  
Marine Systems ◽  
Suspended Solid Concentration ◽  
Good Ecological Status ◽  
Monitoring Activity

Unfortunately, more and more contaminants, such as heavy metals and other organic micro-pollutants, degrade the good ecological status of marine systems. The removal of contaminated sediments from harbours through dredging activities may cause harmful changes in the environment. This present work shows how monitoring the activity and validated numerical models can be of great help to dredging activities that can cause environmental impacts due to the increase of the suspended solid concentration (SSC) and their dispersion and deposition far from the dredging point. This study is applied to a hypothetical dredging project in a very vulnerable coastal site in Southern Italy, the Mar Piccolo Basin. A statistical analysis of the simulated parameter SSC was carried out to numerically estimate its spatial (vertical and horizontal) variability, thereby allowing an evaluation of the potential environmental effects on the coastal area.

scholarly journals Influence of Anthropogenic Loads on Surface Water Status: A Case Study in Lithuania

2021 ◽  
Vol 13 (8) ◽  
pp. 4341
Author(s):  
Laima Česonienė ◽  
Daiva Šileikienė ◽  
Vitas Marozas ◽  
Laura Čiteikė
Keyword(s):  
Total Nitrogen ◽  
Water Status ◽  
Arable Land ◽  
Ecological Status ◽  
Water Bodies ◽  
Agricultural Pollution ◽  
Good Ecological Status ◽  
Water Catchment ◽  
Lake Basins

Twenty-six water bodies and 10 ponds were selected for this research. Anthropogenic loads were assessed according to pollution sources in individual water catchment basins. It was determined that 50% of the tested water bodies had Ntotal values that did not correspond to the good and very good ecological status classes, and 20% of the tested water bodies had Ptotal values that did not correspond to the good and very good ecological status classes. The lake basins and ponds received the largest amounts of pollution from agricultural sources with total nitrogen at 1554.13 t/year and phosphorus at 1.94 t/year, and from meadows and pastures with total nitrogen at 9.50 t/year and phosphorus at 0.20 t/year. The highest annual load of total nitrogen for lake basins on average per year was from agricultural pollution from arable land (98.85%), and the highest total phosphorus load was also from agricultural pollution from arable land (60%).

scholarly journals Macrophyte assessment in European lakes: Diverse approaches but convergent views of ‘good’ ecological status

2018 ◽  
Vol 94 ◽  
pp. 185-197 ◽  
Author(s):  
Sandra Poikane ◽  
Rob Portielje ◽  
Luc Denys ◽  
Didzis Elferts ◽  
Martyn Kelly ◽  
...  
Keyword(s):  
Ecological Status ◽  
Good Ecological Status

A generalized settling approach in the numerical modeling of sedimentation tanks

1998 ◽  
Vol 38 (3) ◽  
pp. 95-102 ◽  
Author(s):  
G. Mazzolani ◽  
F. Pirozzi ◽  
G. d'Antonoi
Keyword(s):  
Transport Model ◽  
Numerical Models ◽  
Removal Rate ◽  
Total Concentration ◽  
Suspended Solid ◽  
Primary Concern ◽  
High Concentration ◽  
Hindered Settling ◽  
Low Concentration ◽  
Solid Distribution

Numerical models for the prediction of turbulent flow field and suspended solid distribution in sedimentation tanks are characterized by refined modeling of hydrodynamics, but apparently weak modeling of settling properties of suspensions. It is known that sedimentation tanks typically treat highly heterodisperse suspensions, whose concentrations range from relatively high to low values. However, settling is modeled either by considering one or more particle classes of different settling velocity, without accounting for hindered settling conditions, or by treating the suspension as monodisperse, even in regions of low concentration. A new generalized settling model is proposed to account for both discrete settling conditions in low concentration regions of the tanks and hindered settling conditions in high concentration regions. Settling velocities of heterodisperse suspensions are then determined as a function of particle velocities in isolation and their total concentration. The settling model is used in the framework of a transport model for the simulation of hydrodynamics and solid distribution in a rectangular sedimentation tank. Results show that solid distribution is mainly affected by particle interactions in the inlet region and by settling properties of individual particles in the outlet region. Comparison of the proposed settling model with other settling models suggests that a generalized approach of the modeling of settling properties of suspensions is a primary concern to obtain reliable predictions of the removal rate.

scholarly journals EFICIÊNCIA DE DIFERENTES ELEMENTOS FILTRANTES NA PREVENÇÃO DE OBSTRUÇÃO DE GOTEJADORES

Irriga ◽  
2003 ◽  
Vol 8 (1) ◽  
pp. 78-87 ◽  
Author(s):  
José Euclides Stipp Paterniani ◽  
Marcos Eduardo Scatolini
Keyword(s):  
Irrigation Water ◽  
Suspended Solid ◽  
Filter Element ◽  
Solid Concentration ◽  
Algae Removal ◽  
Mesh Screen ◽  
Suspended Solid Concentration ◽  
E Mail ◽  
Synthetic Fabric ◽  
Continuous Average

EFICIÊNCIA DE DIFERENTES ELEMENTOS FILTRANTES NA PREVENÇÃO DE OBSTRUÇÃO DE GOTEJADORES   José Euclides Stipp Paterniani Marcos Eduardo ScatoliniFaculdade de Engenharia Agrícola, Universidade Estadual de Campinas, Campinas, SP. CP 6011, CEP 13083-970, E-mail: [email protected]   1 RESUMO  Durante ensaios para verificação de eficiência de retenção de algas em filtros de discos 120 MESH, tela 120 MESH e manta sintética não tecida, foram avaliados o grau de obstrução de gotejadores de labirinto com fluxo turbulento e vazão nominal de 4 L.h-1 e 8 L.h-1. Para determinação da obstrução causada por impurezas não retidas no meio filtrante foram avaliadas a evolução da vazão e da uniformidade estatística dos gotejadores submetidos aos diferentes meios filtrantes durante um período de 22 semanas durante 4 horas diárias e comparadas com uma parcela testemunha sem elemento filtrante. Os resultados mostraram que houve diferença significativa entre o elemento de discos, que apresentou maior uniformidade estatística, os filtros de manta e tela com valores intermediários e a testemunha que apresentou menor uniformidade estatística. No entanto, para caracterizar de maneira definida a diferença no desempenho dos elementos filtrantes, estes valores deveriam vir acompanhados de uma redução contínua na vazão média dos tratamentos, o que foi observado apenas para o elemento de tela com o gotejador de 4 L.h-1. As demais variações da uniformidade estatística foram temporais, provavelmente devido a obstruções  temporárias ocasionadas por variações da concentração de sólidos suspensos na água de irrigação.  UNITERMOS: Filtragem, Gotejamento, Qualidade da água.   PATERNIANI, J.E.S.; SCATOLINI, M.E. EFFICIENCY OF DIFFERENT FILTER ELEMENTS TO PREVENT TRICKLE CLOGGING   2 ABSTRACT  This work aimed to verify the efficiency of algae removal in disks 120 mesh, screen 120  mesh, and non woven synthetic fabric filters. It was evaluated the degree of clogging of turbulent flow drippers on 4 L.h-1 and 8 L.h-1 outflow. For blockage determination the outflow evolution  and statistics uniformity (Us) of the dripper have been evaluated when submitted to different filter media over 22 weeks, 4 daily hours compared to a control without the filter element. The results indicated significant differences among the elements. The disk element presented greater statistic uniformity. The screen filter and the non woven synthetic fabric element presented intermediate values whereas the parcel with no filter element (control) presented minor statistic uniformity. However, in order to characterize performance differences among them, values should be presented along with a  continuous average outflow reduction in all treatments. This pattern was observed only for the screen filter and 4 L.h-1 drippers. The statistics uniformity variation has been probably caused by temporary blockages due to variation in suspended solid concentration in irrigation water.  KEYWORDS: filtration, drip irrigation, water quality. 

scholarly journals Its present state overmoistened landscape systems of Lviv Region

2014 ◽  
pp. 347-354
Author(s):  
N. Blazhko
Keyword(s):  
Key Words ◽  
Present State ◽  
Environmental Conditions ◽  
Ecological Status ◽  
Ecological Condition ◽  
Wetland Landscape ◽  
Current State ◽  
Destabilizing Factors ◽  
Good Ecological Status ◽  
Stabilizing Factors

Reviewed the current state of wetland landscape systems (PLC) Lviv region. Highlighted areas PLC of good ecological status, with a satisfactory ecological condition and unsatisfactory environmental conditions. Key words: overmoistened landscape systems (OLS)peat, peat, drainage improvement, environmental stabilizing factors, environmental destabilizing factors.

Hurdles for implementation of constructed wetlands as Nature-based Solutions in Sweden

2021 ◽  
Author(s):  
Julián Andrés García Murcia ◽  
Fernando Jaramillo ◽  
Sofia Wikström
Keyword(s):  
Water Framework Directive ◽  
Constructed Wetlands ◽  
Ecological Status ◽  
Nutrient Loads ◽  
Structured Interviews ◽  
The Status ◽  
Natural Wetlands ◽  
The Baltic ◽  
Good Ecological Status ◽  
Background Context

<p>Eutrophication in the Baltic Sea has been one of the major environmental issues during the last century partly due to extensive land-use change, loss of natural retention systems, and insufficient management. European legislation such as the Water Framework Directive (WFD) attempts to guide the recovery of good ecological status from freshwater to the sea, and suggests wetlands as ecosystems that can potentially contribute to achieving this goal. Wetlands are considered remarkable Nature-based Solutions (NbS) for improving water quality by diminishing the nutrient loads. This study aims to set a background context of the WFD implementation in Sweden, determine the status of constructed wetlands, and evaluate the stakeholders’ perspectives to identify the main administrative hurdles of wetland implementation in Sweden. For this purpose, we conducted a narrative review, database analysis, and semi-structured interviews with members of the institutions involved in water management. Our results show that it is essential to find synergies among the WFD and other directives to expand cross-sectoral cooperation, implement adjustments on the funding scheme that includes restoration and maintenance of natural wetlands, and increase compensation periods and cost ceiling. Likewise, it is crucial to perform significant improvements in the monitoring system, including more frequent data collection, as well as exploring new strategies to capture landowners’ interest in the implementation of NbS, such as the Catchment Officers program. Finally, we suggest paludiculture as a promising farming practice to increase proprietors’ attention on novel market alternatives, and in turn, to provide benefits for climate, water, and biodiversity.</p><p><strong>Keywords </strong>Wetlands management · Water Framework Directive · Nature-based Solutions · Eutrophication · Semi-structured interviews · Sweden</p>

scholarly journals Development of a fish-based index for the assessment of the ecological status of Lake Balaton in the absence of present day reference condition

2020 ◽  
pp. 11 ◽  
Author(s):  
András Specziár ◽  
Tibor Erős
Keyword(s):  
Native Species ◽  
Ecological Status ◽  
Fish Fauna ◽  
Native Fish ◽  
Lake Balaton ◽  
Anthropogenic Pressures ◽  
Key Species ◽  
Good Ecological Status ◽  
Electric Fishing

A fish-based index is proposed to indicate the ecological status of Lake Balaton, Hungary in accordance with the standard of the European Water Framework Directive (WFD). The Balaton fish index (BFI) synthetises information of 13 lake-specific fish metrics including gillnetting and electric fishing data of species richness of native assemblages, relative abundance, biomass and age structure of native key species, representation of non-native species and general health status. The main anthropogenic pressures considered were the degradation of littoral habitats, invasion of non-native fish species, eutrophication and fishing/angling including stocking. Ecological quality ratio (EQR) is assessed by relating actual fish assemblage metrics to the supposed undisturbed reference status of Lake Balaton reconstructed by expert judgement based on recent and historic information on the fish fauna and its changes. Values of BFI were consistent and indicated good ecological status of Lake Balaton in the period of 2005–2018. This study provides an example on how an EQR assessment methodology might be established in unique habitats with no possibilities for statistical evaluation of pressure-respond relationships and exact determination of the reference status.

scholarly journals Impact of potash mining in streams: the Llobregat basin (northeast Spain) as a case study

2016 ◽  
Author(s):  
Ruben Ladrera ◽  
Miguel Cañedo-Argüelles ◽  
Narcís Prat
Keyword(s):  
Surface Waters ◽  
Mine Tailings ◽  
Ecological Status ◽  
Policy Makers ◽  
Mining Areas ◽  
Potash Mining ◽  
Rivers And Streams ◽  
Fluvial Habitat ◽  
Good Ecological Status

Potash mining is significantly increasing the salt concentration of rivers and streams due to lixiviates coming from the mine tailings. In the present study, we have focused on the middle Llobregat basin (northeast Spain), where an important potash mining activity exists from the beginning of the XX century. Up to 50 million tonnes of saline waste have been disposed in the area, mainly composed of sodium chloride. We assessed the ecological status of streams adjacent to the mines by studying different physicochemical and hydromorphological variables, as well as aquatic macroinvertebrates. We found extraordinary high values of salinity in the studied streams, reaching conductivities up to 132.4 mS/cm. Salt-polluted streams were characterized by a deterioration of the riparian vegetation and the fluvial habitat. Both macroinvertebrate richness and abundance decreased with increasing salinity. In the most polluted stream only two families of macroinvertebrates were found: Ephydridae and Ceratopogonidae. According to the biotic indices IBMWP and IMMi-T, none of the sites met the requirements of the Water Framework Directive (WFD; i.e., good ecological status). Overall, we can conclude that potash-mining activities have the potential to cause severe ecological damage to their surrounding streams. This is mainly related to an inadequate management of the mine tailings, leading to highly saline runoff and percolates entering surface waters. Thus, we urge water managers and policy makers to take action to prevent, detect and remediate salt pollution of rivers and streams in potash mining areas.

scholarly journals TOTAL SUSPENDED SOLID DISTRIBUTION ANALYSIS USING SPOT-6 DATA IN SEGARA ANAKAN, CILACAP

2018 ◽  
Vol 5 (2) ◽  
pp. 177 ◽  
Author(s):  
Aisya Jaya Dhannahisvara ◽  
Hartono Harjo ◽  
Pramaditya Wicaksono ◽  
Ferman Setia Nugroho
Keyword(s):  
Chlorophyll A ◽  
Empirical Model ◽  
Field Data ◽  
Near Infrared ◽  
Total Suspended Solid ◽  
Suspended Solid ◽  
Distribution Analysis ◽  
Chlorophyll A Concentration ◽  
Accuracy Test ◽  
Suspended Solid Concentration

Spatial distribution and concentration of Total Suspended Solid (TSS) is one of the coastal parameters which are required to be examined in order to understand the quality of the water. Rapid development of remote sensing technology has resulted in the emergence of various methods to estimate TSS concentration. SPOT-6 data has spatial, spectral, and temporal characteristics that can be used to estimate TSS concentration. The purposes of this research are (1) to determine the best method for estimating TSS concentration, (2) to map TSS distribution, and (3) to determine the correlation between TSS concentration and chlorophyll-a concentration using SPOT-6 data in Segara Anakan. The estimation of TSS concentration in this research was performed using empirical model built from SPOT-6 and TSS field data. Bands used in this research are single band data (blue, green, red, and near infrared) and transformed bands such as band ratio (12 combinations), Normalized Difference Suspended Solid Index (NDSSI), and Suspended Solid Concentration Index (SSC). The result shows that blue, green, red, and near infrared bands and SSC index significantly correlated to TSS. Afterwards, regression analysis was performed to determine the function that can be used to predict TSS concentration using SPOT-6 data. Regression function used are linear and non-linear (exponential, logarithmic, 2nd order polynomial, and power). The best model was chosen based on the accuracy assessment using Standard Error of Estimate (SE). The selected model was used to calculate total TSS concentration and was correlated with chlorophyll-a field data. The result of accuracy test shows that the model from blue band has an accuracy of 70.68 %, green band 70.68 %, red band 75.73 %, near infrared band 65.58 %, and SSC 73.67 %. The accuracy test shows that red band produced the best prediction model for mapping TSS concentration distribution. The total TSS concentration, which was calculated using red band empirical model, is estimated to be 6.13 t. According to the correlation test, TSS concentration in Segara Anakan has no significant correlation with chlorophyll-a concentration, with a coefficient correlation value of -0.265.

Automated Precipitate Identification for Sludge Volume Indicator

2012 ◽  
Vol 488-489 ◽  
pp. 1636-1640
Author(s):  
Han Soo Lee ◽  
Su Dae Kim ◽  
Yong Hyun Kim ◽  
Jung Min Kim ◽  
Sung Shin Kim
Keyword(s):  
Monitoring System ◽  
Standard Procedure ◽  
Automatic Measurement ◽  
Suspended Solid ◽  
Diagnostic Systems ◽  
Current State ◽  
Suspended Solid Concentration ◽  
Processing Techniques ◽  
Solid Liquid ◽  
Solid Liquid Separation

Nowadays, since sewage disposal plant monitoring system is changed to combine automating control system tendency, automatic measurement method is widely applicable water temperature, pH, BOD, COD, suspended solid, etc. And its tendency is accumulated objective data. However, in the case of leaking suspended solid concentration measurement, it is literally not a long way from managing settling procedure. Because it has an effect on SS concentration of leaked water only when settled ability is disturbed. In other words, it means that research about solid-liquid separation activated sludge on automated monitoring system currently lacks, and needs research in this field. Considering that sedimentation process in the biological treatment process is one of the most important part, currently performed way, namely, SVI measured and judged by experienced specialists in standard procedure has weaknesses which objectivity cannot be guaranteed. Therefore, for maintaining the consistency of judging criteria and ensuring continuity of knowledge, objectified in the settling process is needed to build diagnostic systems. This paper proposed the method using image processing techniques over time due to settling of the sludge is analyzed for changes in height, also due to changes in sedimentation rate by analyzing the performance of the sludge settling, then send administrator for the system to pass the current state of the sludge.

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