The presence of grassy-type odors in drinking water has frequently been determined by flavor-prof... more The presence of grassy-type odors in drinking water has frequently been determined by flavor-profile analysis (FPA). Previous work (Khiari etal., 1995) has identified cis-3-hexen-loOl and cis-3-hexenyl acetate as the causes of these odors in laboratory experiments. Both chemicals possess very similar characteristics; however, cis.3.hexenyl acetate has a much lower odor threshold concentration (OTC) than its corresponding alcohol. In this study, both chemicals were identified by both sensory and chemical analyses separately or in combination in natural and treated waters. It was also found that the sensory and chemical characteristics of samples with grassy odors have a tendency to change upon storage and shipment. Hydrolysis was determined to be a major controlling mechanism for the degradation of cis-3-hexenyl acetate and the formation of cis-3hexen-f-ol in aqueous solution. The kinetics of the hydrolysis of cis-3-hexenyl acetate to cis.3-hexen-l-01 was evaluated in bench-scale experiments. These studies showed the concentration of cis-3-hexen-loOl and cis-3-hexenyl acetate to be strongly pH-dependent. This study shows that preservation by refrigeration and adjustment of pH to 4.6 were important steps to be taken when quantitation of the compounds is needed. However, the samples should be analyzed as quickly as possible.
IOP Conference Series: Materials Science and Engineering, 2019
The paper presents the method for calculating the strength of the ship vessel on the longitudinal... more The paper presents the method for calculating the strength of the ship vessel on the longitudinal wave, based on the modern theory of the beam and computer mathematics. It consists of two parts, which are the determination of hydrodynamic loads on the hull during the passage of a wave and the calculation of the stress-strain state caused by the ship vessel as a beam. The main feature of the technique is that the loads and deflection are considered simultaneously, which was made possible by computer mathematics. The developed method allows; increasing the accuracy of calculations of ship hulls for durability, has a relatively low cost, and does not require expensive software.
SEPA anticipates mailing a "screener" questionnaire this fall to collect basic information from m... more SEPA anticipates mailing a "screener" questionnaire this fall to collect basic information from more than 600 water systems that serve populations greater than 10,000. The information collected will be used to select a sample of facilities that will subsequently receive a detailed questionnaire. Water
A modification to the disinfection process, termed the 'disinfection aid process' for was... more A modification to the disinfection process, termed the 'disinfection aid process' for wastewater effluents has been investigated. The addition of a second chemical, 2,2-Dibromo-3-Netrilopropionamide (DBNPA), to supplement the primary disinfectant, chlorine, seems to be an effective method of disinfection leaving little residual and eliminating toxicity problems. Various parameters that have impacts on the disinfection-aid process were investigated.
SEPA anticipates mailing a "screener" questionnaire this fall to collect basic information from m... more SEPA anticipates mailing a "screener" questionnaire this fall to collect basic information from more than 600 water systems that serve populations greater than 10,000. The information collected will be used to select a sample of facilities that will subsequently receive a detailed questionnaire. Water
Specialized sampling equipment and ultra-clean analytical methodology were employed to quantify t... more Specialized sampling equipment and ultra-clean analytical methodology were employed to quantify the concentrations or fluxes of mercury (Hg), cadmium (Cd) and polychlorinated biphenyl (PCBs) in ambient air, precipitation, runoff, sanitary sewer, and wastewater treatment plant (WWTP) influent. The relationship between the atmospheric deposition and runoff on controlled surfaces were explored for the three pollutants. The impact of the atmospheric deposition and runoff to the headwork loading of the WWTP were investigated. Atmospheric deposition was found to be the primary source of the mass of Cd, Hg, and PCBs in runoff from the controlled surfaces. Neither atmospheric deposition nor the runoff was the main sources of the three pollutants to the Detroit Wastewater Treatment Plant (WWTP). Wet weather flow contributes the main portion of the Cd, Hg, and PCBs loading to the WWTP.
A workshop of international drinking water experts was convened in Sedona, Arizona, March 26-27, ... more A workshop of international drinking water experts was convened in Sedona, Arizona, March 26-27, 2001 for the purpose of developing a method for testing drinking water system components for their potential to contribute to taste-and-odor problems in drinking water. The workshop participants derived a method using provisions from European Standards as well as newly developed approaches. It is intended that this method can serve as a temporary procedure for water utilities, as well as a recommended template to derive an official standard. Materials to be tested may include pipes, fittings, ancillaries, joints, lubricants, tanks, and reservoirs. The recommended method includes a migration (leaching) test with chlorinated water, followed by sensory analysis of the samples from the migration test after dechlorination. Sensory analyses use both statistical (e.g., triangle test) and descriptive (e.g. Flavor Profile Analysis) techniques. A decision tree for the results is provided.
Abstract : It is the purpose of this research to further study the kinetics of the RBC process fo... more Abstract : It is the purpose of this research to further study the kinetics of the RBC process for carbonaceous substrate removal using a synthetic sewage. The interest is to concentrate on the mechanism of the reaction and its rate order, both observed and intrinsic. This paper details part of the experimental work of a long range project, the final results of which will be published at a later date. The overall objective is the development of a simplified, practical approach to design. In essence the extremely complicated
SEPA anticipates mailing a "screener" questionnaire this fall to collect basic information from m... more SEPA anticipates mailing a "screener" questionnaire this fall to collect basic information from more than 600 water systems that serve populations greater than 10,000. The information collected will be used to select a sample of facilities that will subsequently receive a detailed questionnaire. Water
Proceedings of the Water Environment Federation, 2000
Non-point and diffuse sources can be the most significant sources of pollutants in a watershed. A... more Non-point and diffuse sources can be the most significant sources of pollutants in a watershed. Atmospheric deposition in its three forms (ambient, dry, and wet) has often been neglected and thus was not included in watershed approach for water resources management. Often regulatory frameworks for water resources protection have not taken into account atmospheric deposition because little or no data is available. The project undertaken is new and unique in its scope and approach to monitor and measure pollutants in atmospheric deposition and its impact on storm water quality within a river watershed. Specialized sampling equipment and ultra-clean analytical methodology were employed to quantify the concentrations or masses in ambient air, precipitation, and runoff for twelve trace metals. These metals include mercury (Hg), cadmium (Cd), antimony (Sb), aluminum (Al), arsenic (As), chromium (Cr), copper (Cu), manganese (Mn), nickel (Ni), lead (Pb), vanadium (V), and zinc (Zn). Meteorological parameters including wind speed, wind direction, temperature, and relative humidity were also measured. This study represents the most complete set of atmospheric concentration and deposition data for trace metals and mercury in an urban watershed at this time. Additionally, this is the first time that mercury together with other trace elements in dry deposition and runoff has been measured in a study of this length. The results of this study provide both the critical information and valuable study approaches to monitor trace metal deposition in urban watersheds.
Proceedings of the Water Environment Federation, 2000
Pollutants loading from non-point and diffuse sources can be the most significant in a watershed.... more Pollutants loading from non-point and diffuse sources can be the most significant in a watershed. Atmospheric deposition in its three forms (ambient, dry, and wet) have been neglected and thus was not included in watershed approach to water resources management. Often regulatory frameworks for water resources protection have not taken into account atmospheric deposition because little or no data is available. The project undertaken is new and unique in its scope and approach to monitor and measure pollutants in atmospheric deposition and its impact on storm water quality. Specialized sampling equipment and ultra-clean analytical methodology were employed to quantify the concentrations or fluxes of mercury (Hg), cadmium (Cd) and polychlorinated biphenyls (PCBs) in ambient air, precipitation, and runoff. The relationship between the atmospheric deposition and runoff on controlled surfaces was explored for the three pollutants, and the impact of the atmospheric deposition to the toxic chemical loading in runoff was investigated. Atmospheric deposition was found to be the primary mass source of Cd, Hg, and PCBs in runoff from the controlled surfaces.
Proceedings of the Water Environment Federation, 2001
Overflows from combined sewers (CSO) during storm events result in the discharge of untreated was... more Overflows from combined sewers (CSO) during storm events result in the discharge of untreated wastewater to receiving waters. Disinfection of CSOs is required under the U.S.EPA 1994 CSO Policy and the Michigan Department of Environmnental Quality (MDEQ) regulations for full body contact protection. The City of Detroit Water and Sewerage Department (DWSD), as part of its NPDES permit is required to construct a treatment facility for CSO from the Baby Creek outfall that includes disinfection, screening and floatable materials removal for the 10-year 1-hour storm event. CSOs disinfection is normally achieved through the use of chemical agents, primarily liquid sodium hypochlorite. Several chemical disinfectants that are potentially feasible for CSO application were evaluated in bench testing and their results are reported.
Proceedings of the Water Environment Federation, 2007
Ultraviolet light (UV) disinfection has gained tremendous popularity in wastewater disinfection o... more Ultraviolet light (UV) disinfection has gained tremendous popularity in wastewater disinfection over the traditional chemical disinfection process using chlorine gas and other chlorine compounds for many reasons. Mainly, UV disinfection offers a safe process by eliminating the use of a dangerous gas and eliminates the production of toxic disinfection byproducts. UV also eliminates the need for chlorine residual removal (dechlorination) using another chemical reducing reagent. Thus, UV disinfection replaces two processes and eliminates completely the on-site storage of dangerous chemicals.
The presence of grassy-type odors in drinking water has frequently been determined by flavor-prof... more The presence of grassy-type odors in drinking water has frequently been determined by flavor-profile analysis (FPA). Previous work (Khiari etal., 1995) has identified cis-3-hexen-loOl and cis-3-hexenyl acetate as the causes of these odors in laboratory experiments. Both chemicals possess very similar characteristics; however, cis.3.hexenyl acetate has a much lower odor threshold concentration (OTC) than its corresponding alcohol. In this study, both chemicals were identified by both sensory and chemical analyses separately or in combination in natural and treated waters. It was also found that the sensory and chemical characteristics of samples with grassy odors have a tendency to change upon storage and shipment. Hydrolysis was determined to be a major controlling mechanism for the degradation of cis-3-hexenyl acetate and the formation of cis-3hexen-f-ol in aqueous solution. The kinetics of the hydrolysis of cis-3-hexenyl acetate to cis.3-hexen-l-01 was evaluated in bench-scale experiments. These studies showed the concentration of cis-3-hexen-loOl and cis-3-hexenyl acetate to be strongly pH-dependent. This study shows that preservation by refrigeration and adjustment of pH to 4.6 were important steps to be taken when quantitation of the compounds is needed. However, the samples should be analyzed as quickly as possible.
IOP Conference Series: Materials Science and Engineering, 2019
The paper presents the method for calculating the strength of the ship vessel on the longitudinal... more The paper presents the method for calculating the strength of the ship vessel on the longitudinal wave, based on the modern theory of the beam and computer mathematics. It consists of two parts, which are the determination of hydrodynamic loads on the hull during the passage of a wave and the calculation of the stress-strain state caused by the ship vessel as a beam. The main feature of the technique is that the loads and deflection are considered simultaneously, which was made possible by computer mathematics. The developed method allows; increasing the accuracy of calculations of ship hulls for durability, has a relatively low cost, and does not require expensive software.
SEPA anticipates mailing a "screener" questionnaire this fall to collect basic information from m... more SEPA anticipates mailing a "screener" questionnaire this fall to collect basic information from more than 600 water systems that serve populations greater than 10,000. The information collected will be used to select a sample of facilities that will subsequently receive a detailed questionnaire. Water
A modification to the disinfection process, termed the 'disinfection aid process' for was... more A modification to the disinfection process, termed the 'disinfection aid process' for wastewater effluents has been investigated. The addition of a second chemical, 2,2-Dibromo-3-Netrilopropionamide (DBNPA), to supplement the primary disinfectant, chlorine, seems to be an effective method of disinfection leaving little residual and eliminating toxicity problems. Various parameters that have impacts on the disinfection-aid process were investigated.
SEPA anticipates mailing a "screener" questionnaire this fall to collect basic information from m... more SEPA anticipates mailing a "screener" questionnaire this fall to collect basic information from more than 600 water systems that serve populations greater than 10,000. The information collected will be used to select a sample of facilities that will subsequently receive a detailed questionnaire. Water
Specialized sampling equipment and ultra-clean analytical methodology were employed to quantify t... more Specialized sampling equipment and ultra-clean analytical methodology were employed to quantify the concentrations or fluxes of mercury (Hg), cadmium (Cd) and polychlorinated biphenyl (PCBs) in ambient air, precipitation, runoff, sanitary sewer, and wastewater treatment plant (WWTP) influent. The relationship between the atmospheric deposition and runoff on controlled surfaces were explored for the three pollutants. The impact of the atmospheric deposition and runoff to the headwork loading of the WWTP were investigated. Atmospheric deposition was found to be the primary source of the mass of Cd, Hg, and PCBs in runoff from the controlled surfaces. Neither atmospheric deposition nor the runoff was the main sources of the three pollutants to the Detroit Wastewater Treatment Plant (WWTP). Wet weather flow contributes the main portion of the Cd, Hg, and PCBs loading to the WWTP.
A workshop of international drinking water experts was convened in Sedona, Arizona, March 26-27, ... more A workshop of international drinking water experts was convened in Sedona, Arizona, March 26-27, 2001 for the purpose of developing a method for testing drinking water system components for their potential to contribute to taste-and-odor problems in drinking water. The workshop participants derived a method using provisions from European Standards as well as newly developed approaches. It is intended that this method can serve as a temporary procedure for water utilities, as well as a recommended template to derive an official standard. Materials to be tested may include pipes, fittings, ancillaries, joints, lubricants, tanks, and reservoirs. The recommended method includes a migration (leaching) test with chlorinated water, followed by sensory analysis of the samples from the migration test after dechlorination. Sensory analyses use both statistical (e.g., triangle test) and descriptive (e.g. Flavor Profile Analysis) techniques. A decision tree for the results is provided.
Abstract : It is the purpose of this research to further study the kinetics of the RBC process fo... more Abstract : It is the purpose of this research to further study the kinetics of the RBC process for carbonaceous substrate removal using a synthetic sewage. The interest is to concentrate on the mechanism of the reaction and its rate order, both observed and intrinsic. This paper details part of the experimental work of a long range project, the final results of which will be published at a later date. The overall objective is the development of a simplified, practical approach to design. In essence the extremely complicated
SEPA anticipates mailing a "screener" questionnaire this fall to collect basic information from m... more SEPA anticipates mailing a "screener" questionnaire this fall to collect basic information from more than 600 water systems that serve populations greater than 10,000. The information collected will be used to select a sample of facilities that will subsequently receive a detailed questionnaire. Water
Proceedings of the Water Environment Federation, 2000
Non-point and diffuse sources can be the most significant sources of pollutants in a watershed. A... more Non-point and diffuse sources can be the most significant sources of pollutants in a watershed. Atmospheric deposition in its three forms (ambient, dry, and wet) has often been neglected and thus was not included in watershed approach for water resources management. Often regulatory frameworks for water resources protection have not taken into account atmospheric deposition because little or no data is available. The project undertaken is new and unique in its scope and approach to monitor and measure pollutants in atmospheric deposition and its impact on storm water quality within a river watershed. Specialized sampling equipment and ultra-clean analytical methodology were employed to quantify the concentrations or masses in ambient air, precipitation, and runoff for twelve trace metals. These metals include mercury (Hg), cadmium (Cd), antimony (Sb), aluminum (Al), arsenic (As), chromium (Cr), copper (Cu), manganese (Mn), nickel (Ni), lead (Pb), vanadium (V), and zinc (Zn). Meteorological parameters including wind speed, wind direction, temperature, and relative humidity were also measured. This study represents the most complete set of atmospheric concentration and deposition data for trace metals and mercury in an urban watershed at this time. Additionally, this is the first time that mercury together with other trace elements in dry deposition and runoff has been measured in a study of this length. The results of this study provide both the critical information and valuable study approaches to monitor trace metal deposition in urban watersheds.
Proceedings of the Water Environment Federation, 2000
Pollutants loading from non-point and diffuse sources can be the most significant in a watershed.... more Pollutants loading from non-point and diffuse sources can be the most significant in a watershed. Atmospheric deposition in its three forms (ambient, dry, and wet) have been neglected and thus was not included in watershed approach to water resources management. Often regulatory frameworks for water resources protection have not taken into account atmospheric deposition because little or no data is available. The project undertaken is new and unique in its scope and approach to monitor and measure pollutants in atmospheric deposition and its impact on storm water quality. Specialized sampling equipment and ultra-clean analytical methodology were employed to quantify the concentrations or fluxes of mercury (Hg), cadmium (Cd) and polychlorinated biphenyls (PCBs) in ambient air, precipitation, and runoff. The relationship between the atmospheric deposition and runoff on controlled surfaces was explored for the three pollutants, and the impact of the atmospheric deposition to the toxic chemical loading in runoff was investigated. Atmospheric deposition was found to be the primary mass source of Cd, Hg, and PCBs in runoff from the controlled surfaces.
Proceedings of the Water Environment Federation, 2001
Overflows from combined sewers (CSO) during storm events result in the discharge of untreated was... more Overflows from combined sewers (CSO) during storm events result in the discharge of untreated wastewater to receiving waters. Disinfection of CSOs is required under the U.S.EPA 1994 CSO Policy and the Michigan Department of Environmnental Quality (MDEQ) regulations for full body contact protection. The City of Detroit Water and Sewerage Department (DWSD), as part of its NPDES permit is required to construct a treatment facility for CSO from the Baby Creek outfall that includes disinfection, screening and floatable materials removal for the 10-year 1-hour storm event. CSOs disinfection is normally achieved through the use of chemical agents, primarily liquid sodium hypochlorite. Several chemical disinfectants that are potentially feasible for CSO application were evaluated in bench testing and their results are reported.
Proceedings of the Water Environment Federation, 2007
Ultraviolet light (UV) disinfection has gained tremendous popularity in wastewater disinfection o... more Ultraviolet light (UV) disinfection has gained tremendous popularity in wastewater disinfection over the traditional chemical disinfection process using chlorine gas and other chlorine compounds for many reasons. Mainly, UV disinfection offers a safe process by eliminating the use of a dangerous gas and eliminates the production of toxic disinfection byproducts. UV also eliminates the need for chlorine residual removal (dechlorination) using another chemical reducing reagent. Thus, UV disinfection replaces two processes and eliminates completely the on-site storage of dangerous chemicals.
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Papers by Khalil Atasi