scholarly journals Energy savings using biofuel in a developing-country water distribution system

2017 ◽  
Vol 18 (5) ◽  
pp. 1554-1563
Author(s):  
Alexandra Archer ◽  
Brian D. Barkdoll

Abstract The practical energy minimization algorithm (EMA) is introduced here to determine if a water distribution system (WDS) can be less energy dependent. The EMA is a simple algorithm that can be used by practitioners in the planning and management of WDS. The EMA employs the Jatropha Curcas (JC) tree as a source of oil for fueling water pumps. The EMA is demonstrated on a WDS in Senegal, West Africa, and calculates the level of JC production required to be self-sufficient in fueling the water system to meet drinking, sanitation, and JC irrigation requirements. It was found that the EMA successfully showed that the demonstration WDS can be energy self-sufficient to provide recommended amounts of drinking water for the people and enough irrigation for the JC trees, but only if greywater was used to supplement the irrigation and if a mechanical press was used in lieu of a hand press to extract the oil from the JC leaves. An adequate amount of oil was thus produced to power the required mechanical press as well. Payback periods of significantly less than the life of the required equipment indicate the viability of JC oil as fuel and the feasibility of having an energy independent WDS.

2007 ◽  
Vol 28 (8) ◽  
pp. 1009-1012 ◽  
Author(s):  
Zhe Zhang ◽  
Carole McCann ◽  
Janet E. Stout ◽  
Steve Piesczynski ◽  
Robert Hawks ◽  
...  

In a 30-month prospective study, we evaluated the efficacy of chlorine dioxide to control Legionella organisms in a water distribution system of a hospital with 364 patient beds and 74 skilled nursing beds. The number of hot water specimens positive for Legionella organisms decreased from 12 (60%) of 20 to 2 (10%) of 20. An extended time (18 months) was needed to achieve a significant reduction in the rate of Legionella positivity among hot water specimens. At the time of writing, no cases of hospital-acquired Legionnaires disease have been detected at the hospital since the chlorine dioxide system was installed in January 2003. Use of chlorine dioxide was safe, based on Environmental Protection Agency limits regarding maximum concentrations of chlorine dioxide and chlorite.


2002 ◽  
Vol 46 (9) ◽  
pp. 95-101 ◽  
Author(s):  
L.K. Bagh ◽  
H.-J. Albrechtsen ◽  
E. Arvin ◽  
K. Ovesen

The biofilm formation rate was measured in situ in a hot water system in an apartment building by specially designed sampling equipment, and the net growth of the suspended bacteria was measured by incubation of water samples with the indigeneous bacteria. The biofilm formation rate reached a higher level in the hot water distribution system (2.1 d−1 to 2.3 d−1) than in the hot water tank (1.4 d−1 to 2.2 d−1) indicating an important area for surface associated growth. The net growth rate of the suspended bacteria measured in hot water from the top, middle and bottom of the hot water tank, in the sludge, or in the water from the distribution system was negligible. This indicated that bacterial growth took place on the inner surfaces in the hot water system and biofilm formation and detachment of bacteria could account for most of the suspended bacteria actually measured in hot water. Therefore, attempts to reduce the number of bacteria in a hot water system have to include the distribution system as well as the hot water tank.


Energies ◽  
2021 ◽  
Vol 14 (2) ◽  
pp. 302
Author(s):  
Shintaro Negishi ◽  
Takashi Ikegami

A new robust scheduling method for pumping water in a water distribution system under the uncertainty of activating regulation reserves is proposed in this paper. During the operation of power systems, utilizing the energy equipment of the customer to enhance supply-demand control is attracting attention. Because water pumps have been already installed, they can be regarded as a relatively inexpensive, operational, and flexible resource. Changes in the operation of the water pump can contribute to the power supply and demand control. The proposed method helps generate a robust daily schedule for pumping water and provides regulation reserves under the uncertainty of activating regulation reserves. It is based on electric energy prices and regulation reserves, hourly water demand profiles, and the properties of water flow quantity and the electricity consumption of water pumps. This method comprises an optimization model formulated using mixed integer linear programming, validated through simulations of water pumping scheduling under certain scenarios. The results indicate that the net operational cost decreased when water pumps provided regulation reserves; further, the operational feasibility of providing these reserves from water pumps is clarified. The proposed model makes it possible to optimize power system operation that integrates the water supply system.


1985 ◽  
Vol 6 (4) ◽  
pp. 141-146 ◽  
Author(s):  
Janet E. Stout ◽  
Victor L. Yu ◽  
Paul Muraca

AbstractAlthough the mode of transmission of L. pneumophila is as yet unclear, the hot water distribution system has been shown to be the reservoir for Legionella within the hospital environment. In this report we identify a previously unrecognized reservoir for L. pneumophila within the hospital environment, ie, the cold water dispensers of hospital ice machines. The cold water dispensers of 14 ice machines were cultured monthly over a 1-year period. Positive cultures were obtained from 8 of 14 dispensers, yielding from 1 to 300 CFU/plate. We were able to link the positivity of these cold water sites to the incoming cold water supply by recovering L. pneumophila from the cold water storage tank, which is directly supplied by the incoming municipal water line. This was accomplished by a novel enrichment experiment designed to duplicate the conditions (temperature, sediment, stagnation, and continuous seeding) of the hot water system. Our data indicate that significant contamination of cold water outlets with L. pneumophila can occur. Although no epidemiologic link to disease was made, the fact that the primary source of a patient's drinking water is from the ice machines warrants further investigation of these water sources as possible reservoirs.


Author(s):  
Jinmei Li ◽  
Shuting Zhang ◽  
Lizheng Guo ◽  
Lihua Chen ◽  
Zhisheng Yu

Abstract The generation and dissemination of antibiotic resistance bacteria (ARB) and antibiotic resistance genes (ARGs) in the environment has become a critical risk to human health. This study is based on a pilot-scale simulated water distribution system to understand the effects of chlorine disinfection treatment (without free chlorine) on ARB and ARGs in biofilms. The hydraulic parameters and pipe materials of the system were simulated based on a drinking water system. The results of the colony counts showed that bacterial multi-antibiotic resistance could be enhanced 13-fold in the biofilms of pipeline. The use of high-throughput qPCR (HT-qPCR) indicated that the total relative abundance of ARGs in biofilm samples increased significantly (p < 0.05), while the diversity of bacteria was shown to be reduced via taxonomic analysis of the V3–V4 region of 16S rRNA. The prominent types of ARGs were conferred resistance by aminoglycoside and β-lactam after the chlorine disinfection treatment, and antibiotic deactivation was the main mechanism. Phyla Proteobacteria had the highest abundance in both treatment and control groups but decreased from 70.81% (initial biofilm sample) to 26.09% (the 6th month biofilm sample) in the treatment groups. The results show that the chlorine disinfection plays a role in the risk of development of bacteria antibiotic resistance in pipe networks owing to bacteria in biofilms. This study was the first to investigate the contribution of chlorination without free chlorine to the bacterial community shift and resistome alteration in biofilms at a pilot test level.


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