scholarly journals Evaluation of a Smectite Adsorption-Based Electrostatic System to Decontaminate F− Rich Thermal Waters

Water ◽  
2022 ◽  
Vol 14 (2) ◽  
pp. 167
Author(s):  
Fabio Fanari ◽  
Matteo Bruno Lodi ◽  
Worash Getaneh ◽  
Alessandro Fanti ◽  
Francesco Desogus ◽  
...  

Several studies have shown the presence of fluoride levels much higher than the 1.5 mg/L threshold concentration recommended by WHO in the spring waters and wells of the Ethiopian Rift Valley. Available defluoridation techniques can be costly, present complicated technical aspects, and show limited effectiveness. Therefore, it is necessary to devise innovative, sustainable, and effective solutions. This study proposes an alternative method of intervention to the known techniques for removing fluoride from water, particularly suitable for smaller rural communities. In particular, in this work, the possibility to use electromagnetic fields as a physical method for removing the excess fluoride was investigated. The study was carried out by developing a multiphysics model used for studying and envisaging the design of a device. In this framework, the combination of this approach with the use of highly reactive smectite clay was numerically studied. The results obtained, although preliminary, indicate that the proposed system could significantly impoverish the waters of the Rift Valley from fluoride, with the consequence of obtaining a resource suitable for human consumption, in particular for rural communities. However, further theoretical investigations and experimental phases will be necessary to achieve the desired results.

Ibis ◽  
2008 ◽  
Vol 128 (4) ◽  
pp. 469-482 ◽  
Author(s):  
M. M. JAEGER ◽  
R. L. BRUGGERS ◽  
B. E. JOHNS ◽  
W. A. ERICKSON
Keyword(s):  

Hydrobiologia ◽  
1994 ◽  
Vol 288 (1) ◽  
pp. 1-12 ◽  
Author(s):  
Elizabeth Kebede ◽  
Zinabu G. Mariam ◽  
Ingemar Ahlgren

2021 ◽  
Author(s):  
Femke Augustijns ◽  
Nils Broothaerts ◽  
Gert Verstraeten

<p>Within eastern Africa, Ethiopia stands out for its steep topography, resulting in an altitudinal zonation of climate and vegetation. To understand future vegetation changes, we need information on past vegetation covers and vegetation responses to environmental and climatic changes. Pollen studies are available for low and high elevations in Ethiopia, but they are low in number and limited in spatial coverage. In addition, explicit research to altitudinal patterns of environmental changes are missing. However, archaeological evidence from SW Ethiopia suggests vertical migration of humans in response to humidity fluctuations, highlighting the need for research to spatial dynamics of human activities and vegetation in Ethiopia. On the other hand, sedimentological evidence suggests a millennia long agricultural history in Ethiopia’s highlands and several authors identify this region as a center of plant domestication. </p><p>It is clear that a thorough understanding of the past vegetation cover and its alteration by humans and climate is missing for Ethiopia. These research gaps impede identification of the timing and location of the onset of agriculture in the ancient Ethiopian landscape, resulting in poor understanding of e.g. contemporary degraded landforms. In our study, we aim to reconstruct and quantify the vegetation history along an altitudinal gradient in the Southern Ethiopian Rift Valley and to identify the role of man and climate on this evolution. Therefore, several lakes and swamps are selected as study sites along an altitudinal gradient (1100-3000 m a.s.l.) in the Gamo Highlands near the city of Arba Minch, along the Southern Ethiopian Rift Valley. Here, we will present the results of pollen, charcoal and NPP analyses from two wetland sites situated at 2300 and 3000 m a.s.l. The records show an increase of Afromontane forest taxa around 13 ka BP, at the expense of Montane ericaceous taxa. At 8 ka BP, a shift in the composition of the Afromontane forest is observed, together with a change in the fungal assemblage and decrease of grasses. Around 6 ka BP, Wooded grassland taxa increase simultaneously with <em>Delitschia</em> fungal spores. Montane forest taxa increase again at 2.5 ka BP, together with a shift in fungal spores, followed by an increase in charcoal accumulation during the last millennium. Most of the observed transitions can be linked to other vegetation records from Ethiopia, and reflect responses to climatic changes such as the African Humid Period. However, the exact timing and  nature of the vegetation changes differs substantially between records, and asks for a denser sampling of palaeoecological records across Ethiopia. In this study, we will link the reconstructed vegetation changes with anthropogenic and natural driving forces, and come up with a reconstruction of the long-term landscape development in the study area in SW Ethiopia.   </p>


Author(s):  
J.G.K. Kangumba ◽  
E.H. Venter ◽  
J.A.W. Coetzer

Conventional methods of ensuring the safety and soundness of cows' milk for human consumption, such as pasteurisation, are not always practical in poor socioeconomic conditions or in rural communities that lack modern amenities. Activation of lactoperoxidase (LP) system and souring of milk were investigated as potential alternative methods to sustain the safety of milk by inhibiting certain microorganisms with known pathogenic potential. The activation of the LP-system inhibited the growth of Staphylococcus aureus and Escherichia coli by the order of 2 log values. The inhibition of Brucella abortus was negligible. The replication of Coxiella burnetti in milk was not disturbed even after 17 h of LP-system activation at 20 oC, but the outcome of the LP-system treatment on Mycobacterium bovis could not be determined as the conventional culturing technique used to grow this organism did not allow full recovery. Souring inhibited the growth of S. aureus and E. coli also by the order of 2 log values. From the results obtained in this investigation are concluded that the activation of the LP-system and souring can be used to inhibit the growth of S. aureus and E. coli in cows' milk, thereby increasing its safety.


2016 ◽  
Vol 25 (3) ◽  
pp. e080 ◽  
Author(s):  
Dolores Agúndez Leal ◽  
Soumana Douma ◽  
Javier Madrigal ◽  
Almudena Gómez-Ramos ◽  
Barbara Vicenti ◽  
...  

Aim of study: Indigenous woody species play an important role as a complement on the diet of rural populations in Niger, especially in periods of food scarcity. However, these species are nowadays overexploited and management programmes are necessary to conserve them. In order to design a conservation programme for edible woody species, this paper presents a sociological analysis about the use of edible woody species and their products during shortage periods in Niger.Area of study: Four villages in two distinct agro-ecological regions were selected to conduct structured enquiries based on focus group discussions and surveys with key informants.Material and Methods: Perceptions of the conservation status of these species were identified; as well the factors affecting food values, perceptions, management and collection practices.Main results: Results show that B. senegalensis was a staple food in the driest areas, and M. crassifolia was used for fodder and human consumption in the most critical situations. The local communities related the drivers of species conservation status specific to the agro-ecological regions, and gender and ethnic differences were also identified.Research highlights: Understanding these factors constitutes a first step towards adaptive management strategies for the conservation of woody food species in rural communities of Niger.Keywords: Africa; biodiversity; cultural preferences; food; NTFPs.


1978 ◽  
Vol 44 (1-4) ◽  
pp. 141-160 ◽  
Author(s):  
Paul Mohr ◽  
Antanas Girnius ◽  
Jan Rolff

Sign in / Sign up

Export Citation Format

Share Document