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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
11

Greywater treatment for reuse by slow sand filtration : study of pathogenic microorganisms and phage survival

Khalaphallah, Rafat 14 September 2012 (has links) (PDF)
In recent decades, most countries of the world have experienced a shortage of water and increase its rate of consumption. Today, every country in the world are interested in this problem by trying to find alternatives to address this shortage. One solution is reuse greywater (GW) for irrigation after treatment. GW is all water generated from Household except toilet water. The risks associated with the reuse of these waters are the presence of pathogens that can infect humans, animals and plants. In this thesis focused on studying treatment by slow sand filtration and the survival of representatives of pathogens, such as E. Coli, P. aeruginosa , E. Faecalis and Bacteriophage MS2 which could be found in the greywater. The study factors was a physico-chemicals factors such as; temperature (6±2,23±2,42±2°c), salinity (1.75 and 3.5% Nacl), oxygen (aerobic and anaerobic condition), nutrient ( rich media , 50%: 50% salt and poor media ), light with photocatalysis ( UV and Visible lights) and slow sand filter (Egyptian desert sand and swimming pool sand). A combination of high temperature, sunlight and photocatlysis are mainly responsible for the rapid decline of bacteria and MS2 coliphage. Slow sand filter have clearly less influence on the survival of bacteria in the greywater, but it effective to decline turbidity and COD for short times.
12

Assessment of a Modified Double Agar Layer Method to Detect Bacteriophage for Assessing the Potential of Wastewater Reuse in Rural Bolivia

Hadley, Sakira N. 01 January 2013 (has links)
Water scarcity is a global concern that impacts many developing countries, forcing people to depend on unclean water sources for domestic, agricultural, and industrial needs. Wastewater is an alternative water source that contains nutrients needed for crop growth. Wastewater reuse for agriculture can cause public health problems because of human exposure to pathogens. Pathogen monitoring is essential to evaluate the compliance of wastewater with established World Health Organization (WHO) and U.S. Environmental Protection Agency (EPA) wastewater reuse guidelines. Indicator organisms are commonly used to detect pathogens in water and wastewater because they are quick and easy to measure, non-pathogenic, and have simple and inexpensive methods of detection. The objective of this research was to develop a modified double agar layer assay method that can be conducted in the field to quantify bacteriophage to assess the quality of wastewater for agricultural reuse. Results from the modified double agar layer assay were used to investigate the potential of somatic coliphage as an indicator organism for assessing the potential presence of enteric viruses in developing world treated wastewater, and to use the criteria of a good indicator organism to compare the potential of two commonly used indicator organisms, somatic coliphage and fecal coliforms, as an indicator of enteric viruses in wastewater. A modified EPA double agar layer method was developed and deployed in a developing world rural community to effectively quantify the concentration of somatic coliphage in a community managed wastewater treatment system composed of a Upflow Anaerobic Sludge Blanket (UASB) reactor followed by two maturation lagoons. The modified method served as a good indicator of enteric viruses in the water. Somatic coliphages were easily detected and quantified in the field setting using a modified double agar layer method. Somatic coliphage was found to be a potential indicator for enteric viruses rather than fecal coliforms because of their similarity in characteristics and resistances to wastewater treatment. The concentration of somatic coliphage was only reduced by 1.05 log units across the two series maturation lagoon system. Previous literature suggested removal would range from 2.1 to 4.6 log units. Influent wastewater (previously treated by an UASB reactor) had a concentration of 4.38 E+06 PFU/ 100 mL (standard deviation = ±3.7E+06, n = 9) and the treated effluent contained 3.90 E+05 PFU/100 mL (standard deviation = ± 4.5E+05, n = 8) of somatic coliphages. Results suggest that somatic coliphage is a good potential indicator for enteric viruses in wastewater but further research needs to be done.
13

Wastewater Reuse: Comprehensive Study about Treatment System Efficiency and Potential Public Health Concerns

Park, Eunyoung January 2015 (has links)
No description available.

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