In Situ Chemical Oxidation
In situ chemical oxidation (ISCO) can be a cost effective remedial option – when applied correctly. To help identify potential failure mechanisms, design parameters, and treatment abilities, bench scale testing is mandatory for a successful full scale application. There are several different oxidant chemistries to choose from and different activators/stabilizing approaches that can be used depending upon the:
- Site characteristics
- Compounds of concern
- Budgetary restraints
- Site goals.
XDD Environmental experience includes:
- Determining the stability of Hydrogen peroxide, which provides stabilizer requirements needed for full scale field applications.
- Measuring of the base buffering for alkaline activation of sodium persulfate.
- Evaluating persulfate and/or permanganate oxidant stability at different concentrations and with different activators to determine the most favorable site approach.
- Calculating the total oxidant demand with varying concentrations and activators to determine the site-specific oxidant demand and therefore loading.
- Full treatability evaluations of the oxidant system to confirm client objectives will be met.
Field applicability is strongly embedded in XDD’s design of our treatability tests. The goal is for the final results to be directly applicable to the full scale design and application. XDD is able to achieve this applicability by
- the use of low pore volume batch tests;
- mimicking site contact (when applicable);
- using only concentrations and activations feasible in the field; and
- considering other site limitations provided during the design phase (such as anticipated radius of influence, access limitations, hydraulic or geologic constraints).
In addition, XDD incorporates our own twenty years of field ISCO implementation experience into the design to increase the usefulness of the results.
XDD performs treatability testing and microcosm studies to evaluate the site specific feasibility and to develop field-scale design parameters for all common in situ remediation technologies:
- In Situ Chemical Oxidation:
- Catalyzed Hydrogen Peroxide
- Activated Persulfate
- In Situ Chemical Reduction:
- Zero Valent Iron (ZVI)
- Bi-Metallic Particles
- Metal Sulfides
- In Situ Bioremediation
- In Situ Metals Stabilization
- pH adjustment
- metals sorption
- metals precipitation
- metals co-precipitation
XDD Environmental will customize our treatability services to meet you site-specific needs. Our most recent approaches include:
- Thermal enhanced soil vapor extraction
- Thermally enhanced bioremediation
XDD uses a methodical approach for our site evaluations. These evaluations are often aided by our state of the art treatability laboratory, confirming that the optimal remediation design has been selected for each site.
Reductive Dechlorination Cultures
Through the acquisition of Bioremediation Consultants, Inc (BCI) methods and equipment, XDD has acquired over 22 specific cultures. These cultures can be grown in site-specific groundwater and provided for bioaugmentation and include:
- Chlorinated Ethane and Ethene reducing cultures.
- Neutral to low pH (5.7)
- Low to high chloride and sulfate concentrations
- Chlorinated benzene reducing cultures.
- BCI’s polychlorinated bi-phenyl (PCB) reducing culture.
In-House Analytical Capabilities
- Natural attenuation parameters
- Dissolved gases such as methane, ethene, and ethane by gas chromatography (GC)
- Volatile chlorinated compounds by GC
- Alcohols, glycols, and water soluble ethers by GC
- Organic acids such as formate, lactate, and acetate by capillary ion electrophoresis and by ion chromatography
- Molecular hydrogen by reduction gas analysis
- Anions such as nitrate, nitrite, phosphate, chloride and sulfate