scholarly journals Municipal waste landfill as a source of polychlorinated biphenyls releases to the environment

PeerJ ◽  
2021 ◽  
Vol 9 ◽  
pp. e10546
Author(s):  
Marta Gabryszewska ◽  
Barbara Gworek

This study aimed to investigate the impact of municipal waste landfill on polychlorinated biphenyls (PCBs) release to the environment concerning groundwater flow directions. The contents of polychlorinated biphenyls in soils, plants and water were analysed at various distances from the landfill. Thanks to low solubility PCBs in water groundwater flow direction, under the landfill, have an influence on PCBs concentration in groundwater. Strong PCBs’ sorption to organic matter caused that no affect groundwater flow directions on PCB content in soils and plants’ tissues was observed. The largest PCBs deposition zone was located 50 m from the contamination source (landfill). Tri-CB and tetra-CB homologues were capable of migration deep into the soil profile, which could be related to the geological material from which the soils under study were developed, as well as to the properties of the PCB homologues.

2018 ◽  
Vol 20 (2) ◽  
pp. 333-344

This study focuses on the impact of the disposal of Tirunelveli city municipal waste in the quality of groundwater in Ramayanpatti village where the waste is disposed; the study also assesses the quality of the groundwater suitability in irrigation in the disposed region. Tirunelveli city generates municipal waste of nearly 15 MLD of domestic wastewater and 100 tons of solid waste in a day. The domestic wastewater is treated by waste stabilization pond. The solid waste is dumped in the open yard. These two disposal sites are located in the Ramayanpatti area and their boundaries are at a distance of 500m from each other. Ground water resources are extracted in use for agriculture in the area of Ramayanpatti. Around thirty, locations have been identified in the Ramayanpatti area for sampling, based on the contour and flow direction. The dominant chemical cation species in the majority of the groundwater samples are in the order of Na>Ca>Mg>K and anion species are in the order of HCO3>Cl>SO4>NO3. Gibbs plot shows that the region is dominated by evaporation and dilution phenomenon. Rhode’s plot shows that there is no reduction in the rate of infiltration of soil in the Ramayanpatti region. Dendrogram shows that the leachates infiltration is predominant in the winter season. The study shows that the groundwater quality, nearer and to the southeastern side of the disposal sites are most affected and contaminated by solid waste leachates. The inference with various irrigation plots show that the quality of groundwater in the southeastern region is doubtful for use in irrigation and the groundwater needs to be assessed in order to use in irrigation for agriculture.


2015 ◽  
Vol 802 ◽  
pp. 640-645 ◽  
Author(s):  
Miskiah Fadzilah binti Ghazali ◽  
Mohd Nordin bin Adlan ◽  
Kamarudin bin Samuding ◽  
Mohamad Razip bin Selamat

The colloidal borescope can be used for measuring groundwater flow directions and velocity. It is an integrated high-resolution flux gate compass with a high-magnification colloid-imaging camera that can measure flow at selected depths within a well. In this study, the colloidal borescope was used to determine flow direction and measure velocity during a pumping test for the riverbank filtration study in Jenderam Hilir, Selangor. During each measurement, the instrument, which monitored the movement of the suspended particles, was inserted into a well at a particular depth (screen well). The relative flow direction was determined by plotting the trajectory and speed of colloidal particles across the screen with AquaLITE Software, which determined the horizontal speed of the particles and flow speed. The groundwater flow pattern was dtermined at four boreholes in the study area, and the groundwater flow velocities were found ranging from 0.72 to 2.45 x (10-4) m/s. The direction of the groundwater flow at boreholes monitoring well 02 (MW02) and monitoring well 19 (MW19) was moved toward borehole pumping well (PW). The groundwater flow at monitoring well 01 (MW01) was moving toward the northwest of the study site which was parallel with the Langat river. The groundwater flow in borehole monitoring well A (MWA) was toward the southern part of the study site and was not affected by the pumping test activities at borehole monitoring well 03 (MW03).


Author(s):  
O. A. Loktionov ◽  
O. E. Kondrateva ◽  
V. V. Yushin

The paper assesses the carcinogenic risks from emissions of solid municipal waste landfill for the case when the residential development zone potentially falls within the boundaries of the sanitary protection zone, as well as for the normal situation when the employee of the landfill is on its territory for 8-hour shift.


Materials ◽  
2021 ◽  
Vol 14 (2) ◽  
pp. 367
Author(s):  
Konstantinos Giannokostas ◽  
Yannis Dimakopoulos ◽  
Andreas Anayiotos ◽  
John Tsamopoulos

The present work focuses on the in-silico investigation of the steady-state blood flow in straight microtubes, incorporating advanced constitutive modeling for human blood and blood plasma. The blood constitutive model accounts for the interplay between thixotropy and elasto-visco-plasticity via a scalar variable that describes the level of the local blood structure at any instance. The constitutive model is enhanced by the non-Newtonian modeling of the plasma phase, which features bulk viscoelasticity. Incorporating microcirculation phenomena such as the cell-free layer (CFL) formation or the Fåhraeus and the Fåhraeus-Lindqvist effects is an indispensable part of the blood flow investigation. The coupling between them and the momentum balance is achieved through correlations based on experimental observations. Notably, we propose a new simplified form for the dependence of the apparent viscosity on the hematocrit that predicts the CFL thickness correctly. Our investigation focuses on the impact of the microtube diameter and the pressure-gradient on velocity profiles, normal and shear viscoelastic stresses, and thixotropic properties. We demonstrate the microstructural configuration of blood in steady-state conditions, revealing that blood is highly aggregated in narrow tubes, promoting a flat velocity profile. Additionally, the proper accounting of the CFL thickness shows that for narrow microtubes, the reduction of discharged hematocrit is significant, which in some cases is up to 70%. At high pressure-gradients, the plasmatic proteins in both regions are extended in the flow direction, developing large axial normal stresses, which are more significant in the core region. We also provide normal stress predictions at both the blood/plasma interface (INS) and the tube wall (WNS), which are difficult to measure experimentally. Both decrease with the tube radius; however, they exhibit significant differences in magnitude and type of variation. INS varies linearly from 4.5 to 2 Pa, while WNS exhibits an exponential decrease taking values from 50 mPa to zero.


2021 ◽  
Author(s):  
Goedele Verreydt ◽  
Niels Van Putte ◽  
Timothy De Kleyn ◽  
Joris Cool ◽  
Bino Maiheu

<p>Groundwater dynamics play a crucial role in the spreading of a soil and groundwater contamination. However, there is still a big gap in the understanding of the groundwater flow dynamics. Heterogeneities and dynamics are often underestimated and therefore not taken into account. They are of crucial input for successful management and remediation measures. The bulk of the mass of mass often is transported through only a small layer or section within the aquifer and is in cases of seepage into surface water very dependent to rainfall and occurring tidal effects.</p><p> </p><p>This study contains the use of novel real-time iFLUX sensors to map the groundwater flow dynamics over time. The sensors provide real-time data on groundwater flow rate and flow direction. The sensor probes consist of multiple bidirectional flow sensors that are superimposed. The probes can be installed directly in the subsoil, riverbed or monitoring well. The measurement setup is unique as it can perform measurements every second, ideal to map rapid changing flow conditions. The measurement range is between 0,5 and 500 cm per day.</p><p> </p><p>We will present the measurement principles and technical aspects of the sensor, together with two case studies.</p><p> </p><p>The first case study comprises the installation of iFLUX sensors in 4 different monitoring wells in a chlorinated solvent plume to map on the one hand the flow patterns in the plume, and on the other hand the flow dynamics that are influenced by the nearby popular trees. The foreseen remediation concept here is phytoremediation. The sensors were installed for a period of in total 4 weeks. Measurement frequency was 5 minutes. The flow profiles and time series will be presented together with the determined mass fluxes.</p><p> </p><p>A second case study was performed on behalf of the remediation of a canal riverbed. Due to industrial production of tar and carbon black in the past, the soil and groundwater next to the small canal ‘De Lieve’ in Ghent, Belgium, got contaminated with aliphatic and (poly)aromatic hydrocarbons. The groundwater contaminants migrate to the canal, impact the surface water quality and cause an ecological risk. The seepage flow and mass fluxes of contaminants into the surface water were measured with the novel iFLUX streambed sensors, installed directly in the river sediment. A site conceptual model was drawn and dimensioned based on the sensor data. The remediation concept to tackle the inflowing pollution: a hydraulic conductive reactive mat on the riverbed that makes use of the natural draining function of the waterbody, the adsorption capacity of a natural or secondary adsorbent and a future habitat for micro-organisms that biodegrade contaminants. The reactive mats were successfully installed and based on the mass flux calculations a lifespan of at least 10 years is expected for the adsorption material.  </p>


Author(s):  
Martin Preene ◽  
Mike Chrimes

The Kilsby Tunnel, constructed in the 1830s, faced severe problems when a section of the tunnel, almost 400 m long, encountered unstable ‘quicksand’ conditions. The engineer for the project, Robert Stephenson, developed an extensive groundwater lowering scheme, unique for the time, using steam engines pumping from multiple shafts, to overcome the quicksand. Modern geological information indicates most of the tunnel was in Middle Lias bedrock, but the ‘quicksand’ section passed through a buried channel of water-bearing sand of glacial origin. In the early 19th century the impact of glacial processes on British geology was not widely accepted and, based on contemporary geological knowledge, Stephenson’s problems appear to be genuine unforeseen ground conditions, not predicted by his experienced advisers. It seems just random chance that trial borings missed the buried channel of sand. The work at Kilsby was two decades before Darcy’s law established the theoretical understanding for groundwater flow, and 90 years before Terzaghi’s effective stress theory described how reducing pore water pressures changed ‘quicksand’ into a stable and workable material. Despite the lack of existing theories, Stephenson used careful observations and interpretation of groundwater flow in the ‘quicksand’ to navigate the tunnel project to a successful conclusion.


2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Ying Zhang ◽  
Yuran Li ◽  
Mark Frost ◽  
Shiyu Rong ◽  
Rong Jiang ◽  
...  

PurposeThis paper aims to examine the critical role played by cultural flow in fostering successful expatriate cross-border transitions.Design/methodology/approachThe authors develop and test a model on the interplay among cultural intelligence, organizational position level, cultural flow direction and expatriate adaptation, using a data set of 387 expatriate on cross-border transitions along the Belt & Road area.FindingsThe authors find that both organizational position level and cultural flow moderate the relationship between cultural intelligence and expatriate adaptation, whereby the relationship is contingent on the interaction of organizational position status and assignment directions between high power distance and low power distance host environments.Originality/valuePrevious research has shown that higher levels of cultural intelligence are positively related to better expatriate adaptation. However, there is a lack of research on the effect of position difference and cultural flow on such relationship. Our study is among the first to examine how the interaction between cultural flow and organizational position level influences the cultural intelligence (CI) and cultural adjustment relationship in cross-cultural transitions.


2013 ◽  
Vol 727 ◽  
pp. 236-255 ◽  
Author(s):  
D. Vigolo ◽  
I. M. Griffiths ◽  
S. Radl ◽  
H. A. Stone

AbstractUnderstanding the behaviour of particles entrained in a fluid flow upon changes in flow direction is crucial in problems where particle inertia is important, such as the erosion process in pipe bends. We present results on the impact of particles in a T-shaped channel in the laminar–turbulent transitional regime. The impacting event for a given system is described in terms of the Reynolds number and the particle Stokes number. Experimental results for the impact are compared with the trajectories predicted by theoretical particle-tracing models for a range of configurations to determine the role of the viscous boundary layer in retarding the particles and reducing the rate of collision with the substrate. In particular, a two-dimensional model based on a stagnation-point flow is used together with three-dimensional numerical simulations. We show how the simple two-dimensional model provides a tractable way of understanding the general collision behaviour, while more advanced three-dimensional simulations can be helpful in understanding the details of the flow.


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