scholarly journals Modeling of the Sedimentation Process in Water

2021 ◽  
Vol 10 (1) ◽  
pp. 9-13
Author(s):  
Indri Zulmisefnides

The sedimentation process occurs in water storage containers. In the sedimentation process, it will be observed how fluid flow occurs and how sedimentation occurs in water. The sedimentation is influenced by the density of the water and the velocity of the water in the water reservoir. This study aims to determine how to model a mixture of solid and liquid particles (suspension) in a water storage container by modeling it into a mathematical form, namely by using differential equations. In this case, the factors that affect the sludge concentration distribution will be used as a reference for modeling the Mathematical equations which will then be solved using differential equations.

Author(s):  
D. Daniel ◽  
Arnt Diener ◽  
Jack van de Vossenberg ◽  
Madan Bhatta ◽  
Sara J. Marks

Accurate assessments of drinking water quality, household hygenic practices, and the mindset of the consumers are critical for developing effective water intervention strategies. This paper presents a microbial quality assessment of 512 samples from household water storage containers and 167 samples from points of collection (POC) in remote rural communities in the hilly area of western Nepal. We found that 81% of the stored drinking water samples (mean log10 of all samples = 1.16 colony-forming units (CFU)/100 mL, standard deviation (SD) = 0.84) and 68% of the POC samples (mean log10 of all samples = 0.57 CFU/100 mL, SD = 0.86) had detectable E. coli. The quality of stored water was significantly correlated with the quality at the POC, with the majority (63%) of paired samples showing a deterioration in quality post-collection. Locally applied household water treatment (HWT) methods did not effectively improve microbial water quality. Among all household sanitary inspection questions, only the presence of livestock near the water storage container was significantly correlated with its microbial contamination. Households’ perceptions of their drinking water quality were mostly influenced by the water’s visual appearance, and these perceptions in general motivated their use of HWT. Improving water quality within the distribution network and promoting safer water handling practices are proposed to reduce the health risk due to consumption of contaminated water in this setting.


Author(s):  
Steven Lacey ◽  
Ramon Lopez ◽  
Charles Frangos ◽  
Amid Khodadoust

In response to a rural community’s concern regarding diarrheal disease, particularly among children, a field assessment was performed to determine the concentration of 4 classes of indicator bacteria: aerobic bacteria, total coliform, fecal coliform and Escherichia coli. Matched supply tap and storage container samples were taken from 28 households; two additional samples were taken at the main storage tank. Total and free chlorine concentration was also determined for each sample. While nearly all samples taken from household taps were near or below limits of detection, samples from storage containers all showed high densities of indicator bacteria and one was positive for Salmonella. All chlorine measurements indicated concentrations of < 0.5 ppm. These data suggest that while the source well water shows indicator bacteria concentrations at or below limits of detection, drinking water becomes significantly more hazardous while in storage containers at the household level, and this reflects insufficient chlorination. An uninterrupted and adequately chlorinated water supply system is planned to eliminate the need for drinking water storage at the household level.


2020 ◽  
Vol 20 (1) ◽  
Author(s):  
Elli Leontsini ◽  
Sean Maloney ◽  
Margarita Ramírez ◽  
Eric Rodriguez ◽  
Tilly Gurman ◽  
...  

Abstract Background In El Salvador, Aedes aegypti mosquitoes transmitting Zika and other arboviruses use water storage containers as important oviposition sites. Promotion of water storage container cleaning is a key element of prevention programs. We explored community perceptions surrounding cleaning practices among pregnant women, male partners of pregnant women, and women likely to become pregnant. Methods Researchers conducted 11 focus groups and 12 in-depth interviews which included individual elicitations of Zika prevention measures practiced in the community. Focus group participants rated 18 images depicting Zika-related behaviors according to effectiveness and feasibility in the community context, discussed influencing determinants, voted on community intentions to perform prevention behaviors, and performed washbasin cleaning simulations. In-depth interviews with male partners of pregnant women used projective techniques with images to explore their perceptions on a subset of Zika prevention behaviors. Results General cleaning of the home, to ensure a healthy environment, was a strong community norm. In this context, participants gave water storage container cleaning a high rating, for both its effectiveness and feasibility. Participants were convinced that they cleaned their water storage containers effectively against Zika, but their actual skills were inadequate to destroy Aedes aegypti eggs. A further constraint was the schedule of water availability. Even during pregnancy, male partners rarely cleaned water storage containers because water became available in homes when they were at work. Furthermore, prevailing gender norms did not foster male participation in domestic cleaning activities. Despite these factors, many men were willing to provide substantial support with cleaning when their partners were pregnant, in order to protect their family. Conclusions Behavior change programs for the prevention of Zika and other arboviruses need to improve community members’ mosquito egg destruction skills rather than perpetuate the promotion of non-specific cleaning in and around the home as effective. Egg elimination must be clearly identified as the objective of water storage container maintenance and programs should highlight the effective techniques to achieve this goal. In addition, programs must build the skills of family members who support pregnant women to maintain the frequency of effective egg destruction in all water storage containers of the home.


Author(s):  
A. Shahid ◽  
M. Ali Abbas ◽  
H.L. Huang ◽  
S.R. Mishra ◽  
M.M. Bhatti

The present study analyses the dissipative influence into an unsteady electrically conducting fluid flow embedded in a pervious medium over a shrinkable sheet. The behavior of thermal radiation and chemical reactions are also contemplated. The governing partial differential equations are reformed to ordinary differential equations by operating similarity transformations. The numerical outcomes for the arising non-linear boundary value problem are determined by implementing the Successive linearization method (SLM) via Matlab software. The velocity, temperature, and concentration magnitudes for distant values of the governing parametric quantities are conferred, and their conduct is debated via graphical curves. The surface drag coefficient increases, whereas the local Nusselt number and Sherwood number decreases for enhancing unsteadiness parameter across suction parameter. Moreover, the magnetic and suction parameters accelerate velocity magnitudes while by raising porosity parameter, velocity decelerates. Larger numeric of thermal radiation parameter and Eckert number accelerates the temperature profile while by enhancing Prandtl number it decelerates. Schmidt number and chemical reaction parameters slowdowns the concentration distribution, and the chemical reaction parameter influences on the point of chemical reaction that benefits the interface mass transfer. It is expected that the current achieved results will furnish fruitful knowledge in industrious utilities.


Open Physics ◽  
2020 ◽  
Vol 18 (1) ◽  
pp. 1100-1107
Author(s):  
Ghulam Rasool ◽  
Waqar A. Khan ◽  
Sardar Muhammad Bilal ◽  
Ilyas Khan

Abstract This research is mainly concerned with the characteristics of magnetohydrodynamics and Darcy–Forchheimer medium in nanofluid flow between two horizontal plates. A uniformly induced magnetic impact is involved at the direction normal to the lower plate. Darcy–Forchheimer medium is considered between the plates that allow the flow along horizontal axis with additional effects of porosity and friction. The features of Brownian diffusive motion and thermophoresis are disclosed. Governing problems are transformed into nonlinear ordinary problems using appropriate transformations. Numerical Runge–Kutta procedure is applied using MATLAB to solve the problems and acquire the data for velocity field, thermal distribution, and concentration distribution. Results have been plotted graphically. The outcomes indicate that higher viscosity results in decline in fluid flow. Thermal profile receives a decline for larger viscosity parameter; however, Brownian diffusion and thermophoresis appeared as enhancing factors for the said profile. Numerical data indicate that heat flux reduces for viscosity parameter. However, enhancement is observed in skin-friction for elevated values of porosity factor. Data of this paper are practically helpful in industrial and engineering applications of nanofluids.


2020 ◽  
Vol 20 (1) ◽  
pp. 302
Author(s):  
Sondang Siahaan ◽  
Rina Fauziah

Mosquitoes have a very important meaning in the health sector because of their role as vectors of various diseases. Diseases transmitted by mosquitoes include dengue fever, malaria and filariasis. These three diseases are transmitted from one person to another through vector intermediaries. Vector is a creature that acts as an intermediary for transmitting   diseases. Tebing Tinggi Village is a densely populated area. The density of the population as well as the constraints of clean water make a lot of water reservoirs to store daily water needs. This can potentially be a breeding ground for mosquito larvae. This study was conducted to determine the density of mosquito larvae, to find out the percentage of house index and container index. This study used a visual method, with a cross sectional approach. Based on the results of research from 18 houses (19.78%) that were larvae positive from 91 houses examined and found 22 containers (5.78%) positive larvae from 380 containers examined. 331 containers of larvae were found in the reservoir of deep water as much as 18 containers (5.43%) and as many as 49 containers of  larvae were found in the external water reservoir (12.24%). The density of mosquito larvae in Tebing Tinggi area is categorized as being with density figures 3 and 4. The amount on the surface of the presence of mosquito larvae in water reservoirs in the house should  the community pay more attention to the cleanliness of water reservoirs and to close water storage so that they are not breeding grounds.


2021 ◽  
Vol 2021 ◽  
pp. 1-9
Author(s):  
Sobia Akbar ◽  
Azad Hussain

Purpose. The flow of nonviscous Casson fluid is examined in this study over an oscillating surface. The model of the fluid flow has been inspected in the presence of oblique stagnation point flow. The scrutiny is subsumed for the Riga plate by considering the effects of magnetohydrodynamics. The Riga plate is considered as an electromagnetic lever which carries eternal magnets and a stretching line up of alternating electrodes coupled on a plane surface. We have considered nonboundary layer two-dimensional incompressible flow of the fluid. The fluid flow model is analyzed in the fixed frame of reference. Motivation. The motivation of achieving more suitable results has always been a quest of life for scientists; the capability of determining the boundary layer of flow on aircraft which either stays laminar or turns turbulent has encouraged the researcher to study compressible flow in depth. The compressible fluid with boundary layer flow has been utilized by numerous researchers to reduce skin friction and enhance thermal and convectional heat exchange. Design/Approach/Methodology. The attained partial differential equations will be critically inspected by using suitable similarity transformation to transform these flows thrived equations into higher nonlinear ordinary differential equations (ODE). Then, these equations of motion are intercepted by mathematical techniques such as the bvp4c method in Maple and Matlab. The graphical and tabular representation of different parameters is also given. Findings. The behavior of β and modified Hartmann number M increases by positively increasing the values of both parameters for F η , while ω decreases with increasing the values of ω for F η . The graph of β shows upward behavior for distinct values for both G η and G ′ η for velocity portray. Prandtl number and β for the temperature profile of θ η and θ 1 η goes downward with increasing parameters.


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