Abstract In-situ remediation using reactive zones is a promising groundwater contaminant treatment technology that involves the injection of a reagent(s) into the subsurface to destruct harmful target chemicals. For efficient and effective treatment the reagent has to be delivered into a specific contaminated zone for the desired chemical reaction(s) to occur. The most commonly used delivery method is a conventional well where the distribution of injected reagent is mainly controlled by the surrounding hydraulic conductivity field. In this case, the reagent is easily delivered into the higher hydraulic conductivity zones but the lower hydraulic conductivity zones are missed. The goal of this research effort is to investigate a novel delivery method involving a single well vertical recirculation system or a dipole well. The configuration of this single dipole well is that injection and extraction occurs from two chambers separated by an impermeable central packer. Thus, this dipole well system can induce predominantly vertical flow across bedding plane features and it is therefore hypothesised that this delivery system can overcome physical heterogeneities creating a more uniform reactive zone. The objective of this research was to demonstrate that the dipole well is a useful delivery tool compared to the commonly used single injection well. Mathematical simulations were used to investigate the delivery performance of a dipole well using steady-state and transient approaches. A simple analytical model was used to determine the steady-state dipole flow field and observe the impact of system parameters on reagent delivery behaviour. The size of coverage area (the area swept by the injected reagent) was used as the performance metric to assess the impact of each system parameter on the dipole well performance. Numerical simulations were used to extend this investigation to homogeneous and heterogeneous (structured or randomly correlated hydraulic conductivity) aquifers under pulsed operation to identify those situations where the dipole delivery system is more efficient or effective. Both forward and backward particle path lines were used to identify reagent coverage areas around the injection well and down gradient. The impact of each system parameters on the dipole well performance was studied. The shoulder length and the injection cost are characteristic parameters that affect dipole delivery performance. A relationship between the down gradient coverage area vs. characteristic system parameters was developed and can be used to predict the dipole well performance in homogenous aquifers. The impact of the hydraulic conductivity distribution on dipole well performance is consistent with either a structured hydraulic conductivity field or randomly correlated hydraulic conductivity fields. Regions of lower hydraulic conductivity can be swept by the dipole well and the dipole well outperforms a single injection well, which is analyzed as a base case in terms of the shape of down gradient coverage area. However, the advantage of dipole well over a single well delivery is small if the degree of heterogeneity is large or the horizontal extent of the bedding plane is small.

Abstract In-situ remediation using reactive zones is a promising groundwater contaminant treatment technology that involves the injection of a reagent(s) into the subsurface to destruct harmful target chemicals. For efficient and effective treatment the reagent has to be delivered into a specific contaminated zone for the desired chemical reaction(s) to occur. The most commonly used delivery method is a conventional well where the distribution of injected reagent is mainly controlled by the surrounding hydraulic conductivity field. In this case, the reagent is easily delivered into the higher hydraulic conductivity zones but the lower hydraulic conductivity zones are missed. The goal of this research effort is to investigate a novel delivery method involving a single well vertical recirculation system or a dipole well. The configuration of this single dipole well is that injection and extraction occurs from two chambers separated by an impermeable central packer. Thus, this dipole well system can induce predominantly vertical flow across bedding plane features and it is therefore hypothesised that this delivery system can overcome physical heterogeneities creating a more uniform reactive zone. The objective of this research was to demonstrate that the dipole well is a useful delivery tool compared to the commonly used single injection well. Mathematical simulations were used to investigate the delivery performance of a dipole well using steady-state and transient approaches. A simple analytical model was used to determine the steady-state dipole flow field and observe the impact of system parameters on reagent delivery behaviour. The size of coverage area (the area swept by the injected reagent) was used as the performance metric to assess the impact of each system parameter on the dipole well performance. Numerical simulations were used to extend this investigation to homogeneous and heterogeneous (structured or randomly correlated hydraulic conductivity) aquifers under pulsed operation to identify those situations where the dipole delivery system is more efficient or effective. Both forward and backward particle path lines were used to identify reagent coverage areas around the injection well and down gradient. The impact of each system parameters on the dipole well performance was studied. The shoulder length and the injection cost are characteristic parameters that affect dipole delivery performance. A relationship between the down gradient coverage area vs. characteristic system parameters was developed and can be used to predict the dipole well performance in homogenous aquifers. The impact of the hydraulic conductivity distribution on dipole well performance is consistent with either a structured hydraulic conductivity field or randomly correlated hydraulic conductivity fields. Regions of lower hydraulic conductivity can be swept by the dipole well and the dipole well outperforms a single injection well, which is analyzed as a base case in terms of the shape of down gradient coverage area. However, the advantage of dipole well over a single well delivery is small if the degree of heterogeneity is large or the horizontal extent of the bedding plane is small.

Thesis (Ph. D.)--University of Texas at Austin, 2002. / Vita. Includes bibliographical references. Available also from UMI Company.

Not available / text

Thesis (M.S. in environmental engineering)--Washington State University, December 2008. / Title from PDF title page (viewed on Apr. 17, 2009). "Department of Civil and Environmental Engineering." Includes bibliographical references (p. 15-18).

Thesis (M.S. in environmental engineering)--Washington State University, August 2009. / Title from PDF title page (viewed on Sept. 10, 2009). "Department of Civil and Environmental Engineering." Includes bibliographical references (p. 14-17).

Thesis (Ph.D.)--University of Nebraska-Lincoln, 2006. / Title from title screen (sites viewed on August 10 , 2006). PDF text of dissertation: [ix], 139 p. : ill. (some col.) ; 1.44Mb. UMI publication number: AAT 3208089. Includes bibliographical references. Also available in microfilm, microfiche and paper format.

Thesis (Ph. D.)--University of Missouri-Columbia, 2007. / The entire dissertation/thesis text is included in the research.pdf file; the official abstract appears in the short.pdf file (which also appears in the research.pdf); a non-technical general description, or public abstract, appears in the public.pdf file. Title from title screen of research.pdf file (viewed Oct. 16, 2007). Vita. Includes bibliographical references.

Thesis (M.S. in civil engineering)--Washington State University, August 2010. / Title from PDF title page (viewed on July 23, 2010). "Department of Civil and Environmental Engineering." Includes bibliographical references (p. 15-17).

Thesis (M.S. in environmental engineering)--Washington State University, August 2010. / Title from PDF title page (viewed on July 30, 2010). "Department of Civil and Environmental Engineering." Includes bibliographical references (p. 13-14).