Drying Kinetics Characteristics of Human Fecal Matter For the Development of Onsite Sanitation Technologies

2021 ◽  
Vol 47 (1) ◽  
pp. 120-130
Author(s):  
K.L Sellgren ◽  
Blessing Makununika ◽  
Brendon Lynch ◽  
Santiago Septien ◽  
Konstantina Velkushanova ◽  
...  

This study aims to define the drying kinetics of two types of human fecal matter, stabilized sludge removed from South African pit latrines and unstabilized fresh fecal material collected from healthy donors in the United States. For the purposes of this study the effects of convection, temperature, and relative humidity on the overall drying kinetics were determined. The differences in drying kinetics observed between stabilized and unstabilized material are hypothesized to be related to increased free water content in the stabilized material. Additionally, we explored a fast and efficient method that could be utilized by in-situ waste treatment technologies to increase the free water content of fresh fecal matter to decrease drying time. The outputs from this study are expected to provide insight for the development of onsite sanitation facilities with in-situ treatment of fecal matter and enable production of a stabilized product that is safe for transport or resource recovery.

1995 ◽  
Vol 58 (5) ◽  
pp. 515-518 ◽  
Author(s):  
SUSANA SANZ ◽  
GLORIA GRADILLAS ◽  
FUENCISLA JIMENO ◽  
CONSUELO PEREZ ◽  
TERESA JUAN

Twenty-one samples from the Cantabrian coast were analyzed to establish their microbiological quality and fermentation tendency. In a food with a very low free-water content like honey, microbiological growth is only possible when there is an increase in water activity. Since most of the samples studied were not extensively granulated, the risk of fermentation is mostly due to high water content. Among our samples, only two had a water content below 17.1% (no risk of fermentation), whereas the high water activity of the rest of the samples indicates the possibility of microbial growth. In fact, four of the samples analyzed showed a moisture content over the Spanish maximum legal limit, which means a high risk of fermentation. The absence of Enterobacteriaceae, coliforms, and Escherichia coli in our samples indicates an appropriate cleanliness during extractions and handling of honey. No Salmonella or Shigella were found. The relationship between water activity and mold and yeast counts found for the honeys analyzed allowed us to divide our samples in two groups: honeys with a high or a low risk of fermentation. Changes observed during storage of the samples confirmed this classification.


1973 ◽  
Vol 12 (65) ◽  
pp. 275-289 ◽  
Author(s):  
Paul M. B. Föhn

AbstractThe daily snow melt calculated from meteorological observations is compared with detailed mass-balance measurements taking into account internal changes in density and free water content in the surface layers of a glacier snow-pack. The energy balance is calculated from measurements obtained by a meteorological station at the experimental site. In addition to the standard ablation measurements the run-off from the melting snow-pack was obtained for a few days. The snow-density profiles were measured with a portable gamma-transmission probe and the liquid-water content of snow was determined by a calorimetric method.Agreement between the melt calculated by the heat-balance method and the mass changes observed in the mass-balance measurements is fair for daily periods. It appears that about 20% of the daily snow melt takes place internally as a result of penetration of solar radiation.


1987 ◽  
Vol 26 (4) ◽  
pp. 264342 ◽  
Author(s):  
T. Hyvarinen ◽  
J. Lammasniemi

1993 ◽  
Vol 18 ◽  
pp. 117-122 ◽  
Author(s):  
Katsuhisa Kawashima ◽  
Tomomi Yamada ◽  
Gorow Wakahama

To investigate the internal structure and transformational processes from firn to ice of the Hisago snow patch on Daisetsu Mountain, Hokkaido, Japan, many drillings were made during the ablation period in 1986 and 1987. The ice cores were analyzed for stratigraphy, density and free water content. The internal structure of the snow patch was characterized by a wet firn layer with abundant ice layers and ice glands overlying a 4.3 m-thick ice body. The thickness of the firn layer varied from 12.7 m in June to 1.3 m in October. A water-saturated firn layer about 1 m thick existed just above the firn-ice transition. The annual layers were identified by dirt layers which showed that 1–2 m of ice was formed each year when the mass budget was positive. Although the densification of the water-saturated firn layer proceeded rapidly, the transformation from firn to ice could not be recognized during the ablation period. It was concluded that the formation mechanism of the ice body comprised three processes: the formation of superimposed ice, the densification of a water-saturated firn layer and the freezing of wet and/or water-saturated firn by cold wave penetration.


Author(s):  
Samuel Renjaan ◽  
Sugiatmo Kasmungin ◽  
Abdul Hamid

<p>The quality of cement is very important because it will greatly help the production well activities especially to make the construction of wells can last long. In this study the influence of lost circulation material (LCM) was analyzed, such as Bagasse, Coconut Fibers, Banana Tree Bark and Sawdust on the physical properties of G-class cement such as rheology, density, free water content, thickening time, and compressive strength. This research was conducted in the laboratory by varying the percentage of LCM from 0% to 6% and temperature from 95oF to 200oF. From this research, it can be known <br />that the addition of LCM can change the physical properties of cement. The highest increase of plastic viscosity (PV) and yield point (YP) values was occurred at 6% concentration of Bagasse, Coconut Fibers, Banana Tree Bark and Sawdust that was 105 cp – 92 lbs/100ft2, 105 cp – 90 lbs/100ft2, 90 cp – 110 lbs/100ft2, and 95 cp – 110 lbs/ft2. The longest thickening time was occurred at 6% concentration of Bagasse, Coconut Fibers, Banana Tree Bark and Sawdust with a soaking temperature of 200 oF which that was 65 minutes, 60 minutes, 66 minutes, and 63 minutes. The highest reduction of density <br />value occured at 6% concentration of Bagasse, Coconut Fibers, Banana Tree Bark and Sawdust that was 15.0 ppg, 15.2 ppg, 15.2 ppg and 15.0 ppg. The decrease in the highest free water content value occurs with the addition of 6% in each type of LCM, namely 0.9 ml, 0.95 ml, 0.9 ml and 1 ml. The increase in the strong press rate occurs in the addition of 1% sugar cane, which is 2838 psi; 1% Coconut fibre is 2926 psi, 0.5% of the banana tree bark is 3080 psi and 1% of sawdust is 2728 psi all at 200 º temperature.</p>


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