scholarly journals Modeling and simulation of in situ bioremediation for TCE-contaminated groundwater through methane injection in Kimitsu city, Japan

2006 ◽  
Vol 6 (2) ◽  
pp. 253-259 ◽  
Author(s):  
S.O. Soda ◽  
M. Kitagawa ◽  
M. Fujita
Keyword(s):  
Competitive Inhibition ◽  
Model Simulation ◽  
Monod Kinetics ◽  
In Situ Bioremediation ◽  
One Dimensional ◽  
Monitoring Wells ◽  
Advection Dispersion ◽  
Degradation Ratio ◽  
Tce Degradation

A one-dimensional model was developed for simulating the in situ bioremediation process in which trichloroethylene (TCE) in groundwater was transformed cometabolically by methanotrophs. The model includes basic processes such as advection, dispersion, and equilibrium sorption of methane, dissolved oxygen, methanotrophs, and TCE. Monod kinetics with a modified competitive inhibition term between methane and TCE, cell inactivation by product toxicity from TCE transformation, and deactivation of the enzyme in the absence of methane were also incorporated into this model. Simulation results were compared with data from a pilot biostimulation test performed at the Kururi site in Japan in 1998. The calibrated model provided good matches to observed changes of the chemical and the most-probable numbers of methanotrophs at the two monitoring wells for the 180 day test. Spatial distribution of the variables and the TCE degradation ratio were also evaluated using the calibrated model.

scholarly journals Comparative application and optimization of different single-borehole dilution test techniques

2020 ◽  
Author(s):  
Nikolai Fahrmeier ◽  
Nadine Goeppert ◽  
Nico Goldscheider
Keyword(s):  
Groundwater Monitoring ◽  
Saturated Zone ◽  
One Dimensional ◽  
Monitoring Wells ◽  
Advantages And Disadvantages ◽  
Advection Dispersion ◽  
Fractured Aquifers ◽  
Tracer Distribution ◽  
Deep Boreholes ◽  
The One

AbstractSingle-borehole dilution tests (SBDTs) are a method for characterizing groundwater monitoring wells and boreholes, and are based on the injection of a tracer into the saturated zone and the observation of concentration over depth and time. SBDTs are applicable in all aquifer types, but especially interesting in heterogeneous karst or fractured aquifers. Uniform injections aim at a homogeneous tracer concentration throughout the entire saturated length and provide information about inflow and outflow horizons. Also, in the absence of vertical flow, horizontal filtration velocities can be calculated. The most common method for uniform injections uses a hosepipe to inject the tracer. This report introduces a simplified method that uses a permeable injection bag (PIB) to achieve a close-to-uniform tracer distribution within the saturated zone. To evaluate the new method and to identify advantages and disadvantages, several tests have been carried out, in the laboratory and in multiple groundwater monitoring wells in the field. Reproducibility of the PIB method was assessed through repeated tests, on the basis of the temporal development of salt amount and calculated apparent filtration velocities. Apparent filtration velocities were calculated using linear regression as well as by inverting the one-dimensional (1D) advection-dispersion equation using CXTFIT. The results show that uniform-injection SBDTs with the PIB method produce valuable and reproducible outcomes and contribute to the understanding of groundwater monitoring wells and the respective aquifer. Also, compared to the hosepipe method, the new injection method requires less equipment and less effort, and is especially useful for deep boreholes.

scholarly journals Application of Combined In Situ Chemical Reduction and Enhanced Bioremediation to Accelerate TCE Treatment in Groundwater

2021 ◽  
Vol 11 (18) ◽  
pp. 8374
Author(s):  
Min-Hsin Liu ◽  
Chung-Ming Hsiao ◽  
Chih-En Lin ◽  
Jim Leu
Keyword(s):  
Ph Value ◽  
Chemical Reduction ◽  
Test Site ◽  
Electron Donors ◽  
Pilot Test ◽  
In Situ Bioremediation ◽  
Oil Emulsion ◽  
Emulsified Oil ◽  
Tce Degradation

Groundwater at trichloroethylene (TCE)-contaminated sites lacks electron donors, which prolongs TCE’s natural attenuation process and delays treatment. Although adding electron donors, such as emulsified oil, accelerates TCE degradation, it also causes the accumulation of hazardous metabolites such as dichloroethylene (DCE) and vinyl chloride (VC). This study combined in situ chemical reduction using organo-iron compounds with enhanced in situ bioremediation using emulsified oil to accelerate TCE removal and minimize the accumulation of DCE and VC in groundwater. A self-made soybean oil emulsion (SOE) was used as the electron donor and was added to liquid ferrous lactate (FL), the chemical reductant. The combined in situ chemical reduction and enhanced in situ bioremediation achieved favorable results in a laboratory microcosm test and in an in situ biological field pilot test. Both tests revealed that SOE+FL accelerated TCE degradation and minimized the accumulation of DCE and VC to a greater extent than SOE alone after 160 days of observation. When FL was added in the microcosm test, the pH value decreased from 6.0 to 5.5; however, during the in situ biological pilot test, the on-site groundwater pH value did not exhibit obvious changes. Given the geology of the in situ pilot test site, the SOE+FL solution that was injected underground continued to be released for at least 90 days, suggesting that the solution’s radius of influence was at least 5 m.

In situ bioremediation of cyanide, PAHs and organic compounds using an engineered SEquenced REactive BARrier (SEREBAR)

2006 ◽  
Vol 14 (2) ◽  
pp. 478-482
Author(s):  
Jamie Robinson ◽  
Russell Thomas ◽  
Steve Wallace ◽  
Paddy Daly ◽  
Robert Kalin
Keyword(s):  
Organic Compounds ◽  
In Situ Bioremediation ◽  
Reactive Barrier

In Situ Bioremediation of Perchlorate in Groundwater

2009 ◽  
Author(s):  
Paul Hatzinger ◽  
Jay Diebold
Keyword(s):  
In Situ Bioremediation

On-site and in situ bioremediation of wood-preservative contaminated groundwater

2000 ◽  
Vol 42 (5-6) ◽  
pp. 371-376 ◽  
Author(s):  
J.A. Puhakka ◽  
K.T. Järvinen ◽  
J.H. Langwaldt ◽  
E.S. Melin ◽  
M.K. Männistö ◽  
...  
Keyword(s):  
Iron Oxidation ◽  
Wood Preservative ◽  
Pilot Scale ◽  
High Rate ◽  
Contaminated Groundwater ◽  
Groundwater Temperature ◽  
In Situ Bioremediation ◽  
Contaminated Aquifer ◽  
Fluidized Bed Process

This paper reviews ten years of research on on-site and in situ bioremediation of chlorophenol contaminated groundwater. Laboratory experiments on the development of a high-rate, fluidized-bed process resulted in a full-scale, pump-and-treat application which has operated for several years. The system operates at ambient groundwater temperature of 7 to 9°C at 2.7 d hydraulic retention time and chlorophenol removal efficiencies of 98.5 to 99.9%. The microbial ecology studies of the contaminated aquifer revealed a diverse chlorophenol-degrading community. In situ biodegradation of chlorophenols is controlled by oxygen availability, only. Laboratory and pilot-scale experiments showed the potential for in situ aquifer bioremediation with iron oxidation and precipitation as a potential problem.

Initial-boundary value problems for the one-dimensional linear advection–dispersion equation with decay

2020 ◽  
Vol 75 (8) ◽  
pp. 713-725 ◽  
Author(s):  
Guenbo Hwang
Keyword(s):  
Boundary Conditions ◽  
Dirichlet Boundary ◽  
Boundary Value ◽  
Initial Boundary ◽  
Initial Boundary Value Problems ◽  
One Dimensional ◽  
Advection Dispersion ◽  
Asymptotically Periodic ◽  
The One ◽  
Initial Boundary Value

AbstractInitial-boundary value problems for the one-dimensional linear advection–dispersion equation with decay (LAD) are studied by utilizing a unified method, known as the Fokas method. The method takes advantage of the spectral analysis of both parts of Lax pair and the global algebraic relation coupling all initial and boundary values. We present the explicit analytical solution of the LAD equation posed on the half line and a finite interval with general initial and boundary conditions. In addition, for the case of periodic boundary conditions, we show that the solution of the LAD equation is asymptotically t-periodic for large t if the Dirichlet boundary datum is periodic in t. Furthermore, it can be shown that if the Dirichlet boundary value is asymptotically periodic for large t, then so is the unknown Neumann boundary value, which is uniquely characterized in terms of the given asymptotically periodic Dirichlet boundary datum. The analytical predictions for large t are compared with numerical results showing the excellent agreement.

In‐situ Bioremediation

2021 ◽  
pp. 1-14
Author(s):  
Shamsul Haq ◽  
Asma Absar Bhatti ◽  
Suhail Ahmad Bhat ◽  
Shafat Ahmad Mir ◽  
Ansar ul Haq
Keyword(s):  
In Situ Bioremediation

scholarly journals Dynamics of Methanotrophs during in situ Bioremediation

2001 ◽  
Vol 16 (1) ◽  
pp. 37-42 ◽  
Author(s):  
Katsuji Tani ◽  
Tomotada Iwamoto ◽  
Kazuo Fujimoto ◽  
Masao Nasu
Keyword(s):  
In Situ Bioremediation
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